Model Engine Maker
Engines => From Kits/Castings => Topic started by: propforward on March 20, 2022, 12:01:03 AM
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Well, on we go then.
There aren't too many build logs of this engine on the net. Stan Shire did a very nice one on this forum, which you can rest assured I will refer to often because it is excellent.
I have a couple of goals beyond making a working engine on this one - well not beyond it, integral to it.
1. Do not scrap a part (not actually that important, but something to strive for).
2. Make parts individually "by the numbers" rather than transfer punching features. Now - I don't consider transfer punching and drilling "wrong", this is simply a measure for me personally of how well I am understanding the parts, the drawings and the machining process. It should be possible to make parts that fit together by making them individually if the tolerances and methods are understood. One exception - I will likely drill and ream the crank bearings mounted on the base plate.
In my opinion the PMR #4 is not an especially elegant engine, but it is a replica of an actual work horse engine - a full size replica, rated at 1/4 horse power. So the larger physical size made it very intriguing to me when I bought the casting set in 2015, and now it is time to move forward with it.
I suspect that being a bit larger it will be less tolerant of alignment errors and such, but in any case I am determined to put everything I have learned so far into practice (rather than learn the same mistakes again :facepalm2:).
Here is a look at the supplied parts.
(https://photos.smugmug.com/Steam-Engines/Shoppe/Lathe-DRO-Install/i-zvf2HnJ/0/c6593d43/XL/Nikon-2022-02-12-0495%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/Shoppe/Lathe-DRO-Install/i-zvf2HnJ/A)
It's quite a lump. Here is the cylinder casting, and I am no waif I can assure you weighing in at (too much) and standing (about this high).
(https://dsm01pap002files.storage.live.com/y4m1CO5f1kEFGIpPuZqtN6R2lCeI-MZRo45wW3SdAw2gZGBZYMAvXQnthEwoWLblcGBFwdFUvzXOV4Nwl9rlmri6mTz9yuHJzA-uC8sIKR4NJCX-JApvTjsiN4Sr7pn2MmA4Cvru9pzU04cHC_RHtuOEHHIx0M_iqFFRCb9QACt8J6Fv3xcwn_V3qfuR6A9OgSB?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mPKsZeuct4pEHnchb15p64H1NHAKR3X38eHlNm3_Ta73yvmg6wxmSAjjAaOhOWeBJlfXnLb4WU3H-QEetovJ04Qa1DqVd_PWlaX-2xVUzlVMDjqdPoxQq_RVjOkKADlaObDUYDjEmTgfVcim9a-IZVltduS03h-d59Fnr_eZGwCY_ySsDfgBhcjeIzTEyGvbY?width=1024&height=768&cropmode=none)
Flywheel is a decent chunk too.
(https://dsm01pap002files.storage.live.com/y4m3oD7wFE2bos_hYK91eirhun22Qe7_r7hHrGij5KKm7Smui6Kvelzh9Ocava8_X9Lf_VjS8HEObN1M6Z5R7GzEit0taH6huilJ0mnYsramfbbkjb7PPc4kZ1yPSeWaRS5O0HDrF0fzQ3at2Ew_wp8eL-MUXscpe7YyK7bCQhD7aH9sH7An65VZkXtfgEUUQws?width=1024&height=768&cropmode=none)
Anyway, the engine itself is actually a fairly straightforward design - but holding the various parts will present some challenges I'm sure. I've had the drawings on the wall of my office at work since the start of the year, so I can peruse them constantly and think through the build a bit, and that has helped me formulate a general approach.
I'm starting with the base. This is because it is a reasonably simple part, but also because the base will go on to become a fixture for machining the bearings in due course.
I started by putting it on a surface plate, and checking flatness and parallelism. It rocked a bit on the surface plate, feeler gauges suggested about 10 thou rock underneath. The top surface was flat within .05", which I think is reasonably good for a raw casting.
(https://dsm01pap002files.storage.live.com/y4mw7QCJzmJX9hGKAe0uzMIx5Zcd_xdIUzJs1Fz96iKD1aNUT6PoioUn_q-7zPkDTeDNU6bPlRf4jPto0TfKdvXtWMz0-PIB-BNlu5YV9c3h4tkAVsKwwd-4jPTuVjUI4zbkHFUuzwa9h6r5uG3rIAuhT6efoG21QwE4WEjH2WyHOTIfiVqE2V8jAaS4vxMFNrA?width=1024&height=768&cropmode=none)
Where I didn't do so well on my last engine was not understanding the starting castings well enough. I'm determined to measure and understand the castings better this time so that I can balance the machining and not run out of machining stock, as well as keeping machining balanced on each surface.
I mounted the base on the mill and shimmed it to get it reasonably level.
(https://dsm01pap002files.storage.live.com/y4mU5cq5ISqeWsARZIIBZ5KD-3z1lErVeyVaJfUxvqXtJXWGQOmYGpn5CacU7oM-BA_qHYVsVweOxbMZ2UdTv-B4RW46dc7Q8leTTjo3eLYBtsBd3qMT4va2QpUBWsHNu7fC4fjIJaLT7bQgfmiEYbTLxeAugId9hgLTjOk6ZSS-HQoYh7k2OZ0PLHVCIk_jyT0?width=1024&height=768&cropmode=none)
Then dusted off the top. I didn't completely clean it up, just about 30 thou to get it to sit flat.
(https://dsm01pap002files.storage.live.com/y4mmIfIz01ugSOcL0qEYzwv6oqxJy0Qzu-0ZbMf6TkvYpM0l9tBMsDPULC9Hsf74F56mNHh-R0shAGpjO_H0zzWb3TzuehhnF8juJj7AXK6uBTKuP-uRcYJlkdSyVML9AY2FCb1OGZ6nmdfjNaVnCAeG59WFsE1qmeSmKOzdjQ0qKmKTZizBuWor5PPzTEkXgrH?width=1024&height=768&cropmode=none)
Here is the drawing, on my trusty rolly cart. Nice to have it presented so that you can see it clearly without tools piled on top of it.
(https://dsm01pap002files.storage.live.com/y4m_JbpFDGDb0hCjhBRW6WbLPLoVaQHBvrOgReryoqr_sx_IHLWnVPWv69ulzJgMFK8Fde7-qqOyezgAgtVIFQcVScff_qYf4_dQAqb0_yl7vAcVejjyzHGkYMssK30sg88Q0rYOAPtM1OQnubmiS3ixkvmA1QZWxeCt2GZYCYIsGuIok3PewK0bdLGr9KMVErG?width=768&height=1024&cropmode=none)
Anyway, after dusting off the top surface I flipped it over and skimmed the underside.
(https://dsm01pap002files.storage.live.com/y4m53tdi6yfHMh0xkiaITnKU5a90LrnjjBisLpH7arT0SbiW-IdugY-cLcChtouWMD9_DX0Pnk6DXAk4RvHyDyxxf9e3-BhmfaxP5aUfI07AdBe_ZlujZsGdgwatS586BL30jXwY5hyNqA1vnLZB9zh8xgDgj3gzibTDBbMtRMruRzncK1N63V9DPph6dYg_Kfq?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4msOjxquUbVObxTv25FMALI9tV-6d7oizHbpS8K0TojXid5AamHJTckWNccQ7zpRrthxpcYa1JIYM_pDt-hfw2lOipaEH3PdX1bUVe9wjn_xWezz6E0IpBh81Uh4o0ldBWUR1msHQT8_i4LYan11Jo1raf8Cs6-oWdI8HZEu6ZKyw3zY8f2xV7uLb3DoV-1jmC?width=1024&height=768&cropmode=none)
Had to reset the clamps after milling part of the base.
(https://dsm01pap002files.storage.live.com/y4md01I5U39Y1F4Ftsr2d3fdWD8mCRR9uMqdyUWLhrEWhgBfS3vdJmMDAOJ5bPpBiCFI-Wt-KHZldTVGfYTA8jNNBn4NeX0ocMfNmSgXXVZ2N1mI8TOo6lk1jJ6c3r7QluOHyyBNfOamj7zAb41HwB4JUFaRPHz5aKOaM7qgOojQy0E71LFYuTqAolGNtreWSbL?width=1024&height=768&cropmode=none)
I checked the top surface for flatness after this step - and it is flat to .0015". I am pretty happy with that to be honest.
Then back on the mill to finish clean up of the top surface.
This time when setting up, I squared the part up using my newly repaired interapid DTI. This is because I'm going to drill and tap the holes in the base as well as do clean up.
(https://dsm01pap002files.storage.live.com/y4mmhQSDzOoCN5aOqerlzcmtCKBGnNvn9j0yB_i2dFEjOBkqDXx6TmspIGwnM0d76TJj2HZPa8MSCGHf8fN1uVeyj3r3CimO2G1PxnJcrQ5Wc1cNhf2gX_T3_M1AmDvCTbR3R_Z7A5xXrg_wXJMHkTcNSWB-zAfWtPnBqSrGBo8luhQsYgke6Ju6p7l_G4hAFri?width=1024&height=768&cropmode=none)
I touched off on the front edge first, and got that square (completely square according to my DRO). I do not run the DTI over as cast surfaces - I touch on one spot, set zero, back off and move down, then touch off again. I chose the front edge arbitrarily. Basically, you have to trust SOMETHING on a casting, so I chose the front edge. After squaring the front edge up, I touched off on two positions on the other 3 edges to check them. The right edge was withing .001", the left within .0006" and the back edge within .005". Not far enough out to warrant any balancing acts - this is plenty good.
So I finished tightening the clamps, and skimmed the top surface clean.
(https://dsm01pap002files.storage.live.com/y4mI1Nx4NDTiikeS8GTnC513iEgzdnSFTnHoq98j1tiw0CtwU72lZBYxmzBKU3Zzv7rav29lDs66sJOvXm0jH7Npoaz_5OHjrUHbFpzS4QNJGy7Xf-dp9qiQF784Q8GMrUhiwslUm3fpXiKMCDT0NvpJSZQ0PHM___PtDz87ZqNSkQZoh9-E7LBu4znGubn4sIC?width=1024&height=768&cropmode=none)
And that's where I am.
Next step will be to drill and top the holes in the top surface, then I'll re clamp and drill the holes in the bosses currently being used to clamp the part.
Off and running! :ThumbsUp:
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Great start on a big engine. Got a big bowl of popcorn to match!
:popcornsmall:
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Hi Stewart,
Great start on the new engine. Must be very satisfying to have such a project to prove out your new DRO installations, not to mention the other lathe improvements.
MJM460
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I’ll be 3-4 rows back, sitting comfortable & watching 🍿
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This is fascinating, and educational, for a newby, thanks for posting and I am looking forward to the next installment.
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This will be fun to watch. :popcorn: :popcorn: I hope your air compressor is up for the challenge. :Lol:
Cheers Dan
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Thanks everyone for looking in and following along. I appreciate the interest very much, and any and all critique / suggestions along the way gratefully received.
MJM - absolutely, it is very pleasing to see tweaks and mods to the machine tools bearing fruit. I just swept the surfaces of this part and they are flat to within half a thou, and no sign of saw toothing from the face milling process - so that means my mill is trammed reasonably well and pleases me very much.
The next stage was pretty simple, just drilling and tapping holes. Not very much to say about it, the main point I guess is that to keep everything as visually symmetrical as possible I established the center lines in X and Y axis by using an indicator mounted in the spindle. A technique I got from Joe Pie on youtube, and who's channel I thoroughly recommend. Not that this is a unique to him approach, just one I wasn't practiced in using, and I must say I do like this for finding center on awkward parts where an edge finder doesn't work out so well.
Simply rotate sweep and find the high spot of your indicator on one side, set zero, move to the opposite edge, find the high spot, move the table to get zero on the indicator, then move to half the value of the measured dimension and there is zero. Not a very good explanation - best to just watch the man himself if you aren't familiar with this technique:
https://www.youtube.com/watch?v=RygvDDyA2X4
Anyway, couple of pics
(https://dsm01pap002files.storage.live.com/y4mejr_wYZRYGjyKWwDIhFNDaIrC2Rg1rLLucbANUOeSz7fY_1oOnxLK6R7jdbwGEExFud-8Tyfczet03FSSd0jyz_wwsTuvGYP6w13V4NW4spCnzSc1Dx4OnYTpo46rjWZhPxfiNAAeb9EC8LvX0W7I_f8c78UvITxbaKdPXLo9-E8IBdma3bZdT11_98TzHl5?width=1024&height=768&cropmode=none)
Having done that, it's a matter of center drilling locations, drilling the pilot holes and then tapping. I have taken to using a spring loaded tap plunger because it does make getting straight threads much easier.
(https://dsm01pap002files.storage.live.com/y4mF8j8O_zz8xsIV7jAIxOmZVrzmnmpf4nwEXla7ogItSK5g_lLCRMbIXkjT-nA6Rdh6K5YEDK1lORXZqt2dvnhD9PfzfE-gjiCO6Uu6Zo6P3_GF7wv2iX0zPEyrUhZBH-lOArFw_kb2gyIA4KGneTvXLRqG8MnIPdxnPX_Q45nHt7ayt09dFq9HO7kfoEcSnHo?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mnZvOXjpTpa-RH7fICBYFWwbagmk5mMRZSCqPrpe4oIzc5R2XQrxGcpXrdEwcRGaLbDd_m4awJPFX18IIhbOCCJL7DIJO1gFH8SpROil31rx7s6LNzyzUYXZsv2IgD82_OsS2txvB4bXHq_JvX2uwt_OzZtBupJJYdn98VwWnMfd7_chCI-ambmHF33uQNnFx?width=1024&height=768&cropmode=none)
I also set about the part with my files and cleaned it up. Should have done that first - note to self for the next parts.
(https://dsm01pap002files.storage.live.com/y4mCvCcMMIZmh7ak71-GdRs_ETFp9vXUXSj0iDsEFspHM4bAKqlnJM71iXTCl9ImS8_v5bjJ8YLVD8nNh99K7Olte568pYM7o_FxvAnYICnnT2I9nK9h_oVfgi_xMUyoD2PGujLY97sZqXNUZ0Feo_roDho-lucqczFdYODwCQxJaZOpqEGhMILQWtYbf6s7Ql3?width=1024&height=768&cropmode=none)
I reckon I could have made this part in at least 2 less set ups, but I'm less concerned about that efficiency right now, and mostly focused on part accuracy.
Anyhoo, speaking of next parts, the column is up next.
(https://dsm01pap002files.storage.live.com/y4mb0HM4TgtYk9D1Bd-CF5nDWhoAo0oVfh148Mrt8-qskeWmCDNNhRDHPU9yTweVPjJnKYsQNycY5XapRdT22jQzM67ZNy9CdB04M8z-Zxp1PQRH983-tDJeiz1LPuF02JRiE0xGUxd-zmKoEvGEXhGQ45ibnF2S7jLoh6HwzAdY2BLoxO6xLuGUEArUUofu0QA?width=1024&height=925&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4myHaesmw_k8JE5Q-eWMchYrlieiPWaWDD_lgw-Z_zLw8bhaDeFad98j-gXoTIxmBdbuwqLKXiZZMmMS6BKRhWjWlzvvjifGQfEdZP3c_MZBRbk1BJCc1j8XZ3PG1CkksHP20iJgGvQAdqjfcue63uLRwZ4NQ5EfSHmdDqKoAaS2APqIzgQjQCQmfffjvim2yJ?width=768&height=1024&cropmode=none)
First thing will be to spend some time with the files on it, and in the meantime I'm mulling over the approach for it. Stan Shire faced the bottom of the feet in a lathe, using a mandrel to keep everything square to the cast bore. I'm more inclined to either face mill or side mill the feet flat, but also using a mandrel to maintain squareness to the bore. I think side milling may be difficult because of the size of the feet, so I may have to make up a jig to clamp the feet and stop them vibrating / deflecting when face milled.
More to come!
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This will be fun to watch. :popcorn: :popcorn: I hope your air compressor is up for the challenge. :Lol:
Cheers Dan
Just the excuse I need for a new compressor. :LittleDevil:
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I will be watching this build with interest, will be some interesting challenges, what a beast, how much does the kit weigh. I looked at this engine a while ago, would have to re-mortgage the house to pay for shipping to Aus,
Gary
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I'll also be following along! One of these days I'd like to attempt a larger engine also!
Good work so far and good luck as you progress!
Mike
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looks like a nice sized engine
why would you set to the cast bore its just a cored hole to be machined it should be set to the out side of the casting that is unmachined
that need to look right the bore is machined so will be concentric if it is a bit off as cast it does not matter if there is enough metal to clean up to size and will be correct with the unmachined part .the machining will make it true to the out side the machining may be uneven to start
with but that does not matter it will come true as you machine it cores often won't be perfect in the centre and can often be off by what looks
like a big amount it is ok as long as there is enough metal to kleen up to size and true to the unmachined parts. which you should have set it up to.
John
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Thanks everyone for your support - really good to have you all following along.
Baltic - not sure on the weight of the engine - it's plenty massive though. 19 inches tall, 1-1/2" bore with a 2-1/2" stroke.
Mike - thanks so much for following it means a lot.
John Mills - you have a solid point, and I've been thinking about that. One reason I was going to set up off the cast bore is that I have seen two builds done that way very successfully. However, it pays not to take anything for granted. Your comments about centering everything to run true and look right based on the externals are spot on.
Here's what I am now thinking - make a tight fitting mandrel for the bore and set up off that initially. Then indicate the outside of the casting to make sure that is also true, and adjust as needed. Some initial measurements show that the as cast bore is quite close to concentric with the outside, within about .030". It could also be that the mandrel actually gets in the way of keeping the part true. I'll try a few things with the set up and see what makes the most sense. This is not a part to rush the set up on, it's worth taking the time to get it rock solid.
Looks like I have enough travel to stand the column upright for machining.
(https://dsm01pap002files.storage.live.com/y4m20fMpy9Ly80AzPn0IAiI4UKdYt6dSZZvev9kbTsyAVxlzMII9ULYsDiRiry5Rinb_4BbpFZ6OUMmUvma7FuxohrpLOi1AwmyRCuiZAspjYGrWK3ifjvmd92SW0dY0aPi3oSy7_wkfJi6nK-6gKaw_dm3JaVxCeXi11_WTZSJMkNmTFu9PdtK43KgZ4o0tTaa?width=1024&height=768&cropmode=none)
So I started making some restraints for it. I don't want those legs shaking around as I try and clean up the feet.
(https://dsm01pap002files.storage.live.com/y4mBl4qiR3Z6HGYqvIOlOEPBjSYU3uBvacdBbtuf8PZkbSAJsXukYI_kwe_n6oFueIb48KpTol7GOnNKNhj5e4J4FPPKmVv-C5aFsC6GKPhlVO9_wSL-WUaT1m9lMpY0fJPuTDW14TTYhIJitFlrOEyNcqq6POrQWVXzS2nIjH_NveAnkj4krNB_9wYZEgSOtvl?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m-Xt0_nl2H-GgSXsYWcS8WAgjN8uydctIgEZq7LI4rAjITopebSiQgGVYUDHT9ahcDPj56Hs1YlJARPSE-688w1VwEN7oefeziHw7XGUxfvUAw1rQcpiVw-fAoCI4dhRiguaAMiLKAMg4kdMRn_XDKLv0_tsVd5VapuDtB8nfvyCrKSBXx1vCy1o-mew4A_Dm?width=1024&height=768&cropmode=none)
I have to try a couple of approaches to clamping it, but I think I'll just clamp each leg to its own support bracket. I could equally make a spacer block to go between the legs but I don't think that's needed. On the other hand, might be even more rigid.
A company I was working for 14 years ago throw out those steel bars and blocks, as well as some other similar sized pieces, so I nabbed them with their permission. Glad I did! Glad I learned some rudimentary welding as well, it's super handy for making fixtures.
I personally think I'm getting better at it.
(https://dsm01pap002files.storage.live.com/y4mk1epEllxxniJBQDq6pj_RsM1S13g_9Qz2JqG6eULrvB4EN7-rqND6IvMHLsxSeHs9mj33V-3J2KQ4RVsH9JBWczGG-mtHBYDya3rWv-rE5hJwXBwclDKo6bpQHorNVTcDVvYfJO4D3dnXi_XN9UWx6vDSHe5GgtHQBCwsynMWc6EKJz6mXhX7eIJE-crDDWB?width=1024&height=768&cropmode=none)
Spent a little quality time with the column and my dremel getting it fettled, but I feel good about this plan, I think I'll be able to get the part set up during the week and maybe have a first pass at machining the feet next weekend. :ThumbsUp:
(https://dsm01pap002files.storage.live.com/y4m-1mhke9pYUcFqvcP_yaFgOW7FezCRfO-KQGeNJkr_qSI9NgWqN61A5YoH-JT95Gjg9AyJWhWdwTfmzZ-MeP062tu3aoiG-UyxKB1BTmzMwBa8lSmOR5SeY-vCdcgUGHSM757UAmi8mniXJmIdsWr6GoFcRzQPaTvV6LC0oKVz33MZ3CfeoPj4t7Jh5M0nFGk?width=1024&height=768&cropmode=none)
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Great work Stuart, looks a good sized engine. Do you follow Blondihacks on youtube? She has got a build series on one of these currently on the go
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Hey Sam thanks for checking in. Cool that she’s building one as well.
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Progress is slow as usual, but I did get some time today. I took the day off because a friend of mine is coming to visit from the UK, so I had a few hours before needing to go and collect him from the airport, so had some fun getting ready for the next step.
After measuring the body casting carefully I established that of course there are no really straight features on the outside to easily align from, but it appears that the as cast bore is quite straight in the casting, if not round. So I decided to go with the mandrel approach to holding it after all.
Here is a piece of 2" round bar I had on hand, just long enough to do what I want to do.
(https://dsm01pap002files.storage.live.com/y4mkRsovQaAU7geiPxMr6s0mymklrOdVUnkjeqt-PrK9DrlpC-f9H8dWR1UUycbpdEX4YZLgAMk8ov7WS98DMuPRbxglFpF-t9Westi0MEyXca26YetE-6wsYW2mvKKpl3DfSEl3d5gTbVyt7XWfeluRtoA7DtCbt10llAIzyB5qbi5-Ljv4Kf-jCSnnn5SqC47?width=1024&height=768&cropmode=none)
I turned down most of the diameter to get a really close fit in the bore.
(https://dsm01pap002files.storage.live.com/y4mM-rxLDTlo0Lc0vMbM1_rwjc77YzE6psAKk0m_YgDmPu-fNaZ8QCIZfIde52G6SBmKvrBvEu9A_EKRF-gxw-kO9m3CGedE5C7Ftp5w6xTSm6_Dvcm0gMRO8mDPfeK3tNloCvfFA1WGOcPKo0Vq5fREHzGUEBrjqDWtSFvzj_y2ljO7KI3AHWAk-Q5Ilg6dUx5?width=1024&height=768&cropmode=none)
After making that working diameter, I mounted the 4 jaw chuck, turned the bar round and held it on the machined diameter, and clocked it in to be very true, then faced the opposite end square.
(https://dsm01pap002files.storage.live.com/y4mrsag6-STWRln9EAPWT-AOu1-gdSw_7UjX7ODkWX_FJ9BHMcr1qPb0ZtXf_EYIzCf9tC72Y-98dWYisPcEGQauM_1QnhA2_KYhuk2L5WC9cUl6wMNqZ98A_i6l13HlHjDYZgCWe9RdW_Kcc6MtPbsFs_s-pPBnHFDD4_diR3GGqm1HQ2qb8OPBaHrmr9IzbY7?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m0QBaBtpXnUZy00mfqtt-JZJlb-eU2j7ZnLGnppoqNAokN12Y9C_x7oLUdzFKLbKviqr39gImMw3rEXbt3gwCT7wGgvsXuzwlZY5LnWtFImfGYRtxXV1DNTzRPK7MIGYoxRYfYYLPTmYq_fzkLJ7aOtM6GirU_qBny-Ai1lcqmuUh2uRuvbpKW4RDWURXytfQ?width=1024&height=768&cropmode=none)
I finished the boss OD as well, just in case I need to indicate it later.
(https://dsm01pap002files.storage.live.com/y4ma1xV1X3sdnTsodxgDnmTEPXur2wjvCk8COk6hnM40ldC0EvWa1Pp-9vNRE8i0jTxXZBmCeh17oWtYHxG57ceCDQhPDP-RNxieUo-1Cs7ezqzQnt9IqyOvuJqbeDEgbedaksn7u6lVi_jOcNkwcDUEjfhmv0qjrcHEWTI-rkbi92UVzrYFvLCzOf7JweywL7O?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4muHNdzrtBHail42zlrUROu_hmwwRX0PVdWNdib6Y3WGXPW4jsEr5olIjrVFB6GeSvsEHNnn_3y_kyhksxxvkYTXp7-teqX1TahTKrXO9aCV95WXGfRojaIiDP8Hn3UBZ0cSoThwqAQUuA7Qz4YoZ5FkKt2uNkr4t0GT_OcvtLyAZAIdlj_f3NGzcdl9kHq9Me?width=768&height=1024&cropmode=none)
So the idea is to clamp the part to the table, with the fixture mandrel forcing the part upright. I did clamp the fixture to the table and ran my indicator up and down the shaft using my DTI in the machine spindle, and the part is very straight, plenty accurate enough for this job.
(https://dsm01pap002files.storage.live.com/y4mOS9-6re7kVLOjHJ6BOwEPcp5ZHTR8c2nRUk1n713Gb8WCCKv_5pO8Hhb40LfWtKPfezibt5RV-bTFjm_fP-psNzGbR4-IcOcmNUwg6ZbCSIXxznQ-gLwdJivuWKhOoKFoTP3goZ5IYONa31eI9JlWuInQp4d3xpHKjcP5Dq1A1l1OCsfwYCvkZlu_ZMpYPgW?width=768&height=1024&cropmode=none)
So then I got to work mounting the part. This took some time.
(https://dsm01pap002files.storage.live.com/y4mJKQXE3DNl-gOvmFfDdd54DEltssQmRgZozEnyynub_cRHkKdis7pkEmeZ1CS3re1LVmV4GdgwPfnFHGCH6aYm0nJvImZprjzeYKN1Rxq4BcvC8vCyBEWulHNYJEgiSkjiKyQReo0XORm9mNBaYITBPha_j_RaTP9uOv78UvdU8o4-aABy9646ocAK1M7H1Te?width=1024&height=768&cropmode=none)
I first clamped the top of the mandrel fixture to hold it in place and upright, then lightly clamped the casting on the head end. First I squared it up by touching off on the far side of the casting on each of the two feet.
After that I clocked the sides of each foot, inside and outside to see how true they were. I also measured the width of the feet to understand any asymmetry. Using a combination of my height gauge and the mill DRO, I touched off on the tops of the feet at all extremties, and also on the underside of the head end of the casting to see whether there was any significant tilt, and essentially I have every surface dialled in to within 0.010" - so it is pretty well as straight as it can be.
Couple of pics of touching off on the lower end using both the spindle DTI and height gauge.
(https://dsm01pap002files.storage.live.com/y4mTjc9q9rAKCyZZSDrapIdX9OA1z_w5YMacd4D5j4NWW4WrTBIyQUsAIbdSF4UQLpflU0Ns_QfTcC6YzaUYBUUath7UcMz7VJHpifxKCZ2b3vkpPnEu9yZ01I-Qx8qpgvBb46wQb_RoCgCsiClv90TWaN4V3WVTKTHOEBVKyTJ8PPNc72ynX_dwYU6kmCKZVB_?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mhXcER78_a6DGx30QVr2j_suzDe7OCi9dfQNSu4NQizrmTrbQE3CC9Jh2tT3TN8P8NMNPoYBZFzJ3ur5BB9Dldga4_A-Ti3sL242LN_OHH3tOEGJPUd7v8Q644Jr1MkxZL1qfeEFKBXhBl5wBoOOMcHrF3adf8HqkeCQsU3-RzQn1SP3aEzu5Q7e_5bRuf0Jn?width=1024&height=768&cropmode=none)
As a result of all these measurements I am very satisfied that I can now mill the feet flat, and drill the bolting holes and that this will keep the part visually straight when assembled, as well as maintaining machining stock on the head end. I have also established that to maintain the reference dimensions on the drawing, I will not be able to fully clean up the feet. That is OK - the area of non clean up will be quite small and won't be visible when assembled - but the key is that I understand what the casting is, and so I won't compromise the finished part by accidentally machining the feet back too far.
So - that's it for now. I have to finish clamping the part up and then I can start cutting it, but for now I am wrapping up, and heading to the airport. Have a good weekend all! Looking forward to putting all this prep work into practice. :ThumbsUp:
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Nice jig! Looks like you've got things held very square, Stuart!
Are you planning to support the long legs more before you actually mill them to length? Just seems like you might bend or break one of the legs without more support for them. I seem to remember someone did that? (Tennessee Whiskey, if I remember right?) But maybe if you're just really gentle and take very small cuts?
Kim
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Hi Kim - that is exactly the plan. I have two very stout steel supports, one for each leg. On milling day I’ll re clock everything then bolt those in place. Even then I’ll go easy but they should damp out any vibration and keep the legs secure.
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Hello again.
Had a great weekend - lots of reminiscing with a long time friend from back across the Atlantic. Wine was consumed, tall tales were told. Good times.
But after a fond farewell, I got a couple more hours in the shed, so managed to actually cut some metal.
I squared up the casting just a little bit more, and really got it in a very good position.
Notes sheet as I clocked the various sides and surfaces of the feet, and some reference measurements.
(https://dsm01pap002files.storage.live.com/y4mmW91XK88GXUboQgBK_cmNy0uoFl20Ha_F_GxiWh-tAuhpigFjFqnNqh1cq8zQjRZ6ngv6nlQ2KJZY8u2NWDgACfBZOlyB9fATRppl4obBKwp1S6Mw-co02uEH5QQQcCO2JycCZA2cHDLOfj-QUKoIJBIQlV6SDOHoJjR4qFENYk5_mjIJZZem7M-rkXuS3Mj?width=1024&height=768&cropmode=none)
The conundrum is that there is not enough material on the bottom of the feet to completely clean them up and maintain the 0.44 reference dimension. However, there is .100 of stock on the cylinder end of the casting, and I'm only .03" deficient on the feet, so I can easily maintain the 11.810" dimension and fully clean the cylinder end and the feet. BUT - what does that mean for the whole engine? The bottom of the guide on this casting will now be .03" lower than nominal. As far as I can tell, that won't interfere with the connecting rod. So the .44" ref dimension will end up at .41". On balance I don't think that matters.
(https://dsm01pap002files.storage.live.com/y4m0qH5kklac2MTHNxqhpwn6ADlyea9Y9SBkPaDySBr9DUBhYfsHAvmWV_Kg16SiC8C983XzMnUuztgvD5cZX2G9DIga0_WaaLguDhFzOoQQ4-5A1Orv6yi5Fbpsow0dqAXCDWgM6T_8GKf7cPWQ7gWz9u4TGMexr1XcQnDoCFrFr_blawA9Af5-anM8IhqDkS6?width=768&height=1024&cropmode=none)
So on we go, I skimmed off .02" at a time using a 1" insert end mill. No problem at all.
Intermediate check of foot face to table. At this point I was right on nominal height to maintain the .44" dimension. You can see how much there is to still clean up.
(https://dsm01pap002files.storage.live.com/y4mxdEsP4qDuKEPQT1bx1MM0LF7nkejJqcDHQMuTvjykRqO0UZsFKlIZcQRq6wEBxJyRaC7yTZRBKja30rTfnj3Y_0ntEGgZ1pc4D77uykn6fBScSwL_HzbJ9Sp-Sp5Z2IuAnlK1u8_gOLh9xN5FTdhF8a80cVq9xDrdiTh1Y29flmDv1UV1oP2yPWoJHNSo8zv?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m9xxohvdT7KIaCCzWnRoaKNNOuZTt3-O2bCNM7e5cwfQGuX3j0ix25tEGk56x00ujkfHuaXLZu5M2VorsMvrLEOVvtu-1yQrAHqgavYs5l2S4soRrMCOwbNwGDnH9MYC9p_khDnOfmFiINNX53QJxsK-8T0iS4fSCZ0TjbcyepWKu3SI3SCYKEEVExIuz3ZiQ?width=1024&height=768&cropmode=none)
This is where it is now.
(https://dsm01pap002files.storage.live.com/y4miDOos5eAmLqipjAsrU8-MQHdbvwF2VthDrd2skgsyGoEp4uvUaUDqjalxZQld1FArARFNiz5OPCMX_v8tUsR2jvLugYNm-Mh5-FONB4O5WbECYBO5EV3pumNwTa9GaFEy0IRZVfNzftvmvkqizCNf2aSO2moXCDjGCTpOwVdEifgVa9oSeVDbH2Fl8qEnsxr?width=1024&height=768&cropmode=none)
I'm going to ruminate on that a bit. I think I may well leave it here - there is more than enough seating surface and I don't want to eat into my machining allowance too much for the opposite end.
Anyway, there it is for now. Next step, establish the center and drill the bolt holes. Not today though.
EDIT: On reflection, I've decided to fully clean up the feet, but not drill the mounting holes yet - so squaring the casting up for that operation was for naught, but no matter. Getting it true vertically was important. My reasoning is that the mounting holes need to be centered relative to the finished bore. It will be easier to indicate the finished bore than locate from the mounting holes, so I'll go with that sequence. After cleaning up the feet, next operation will be to mount on the face plate on the lathe and machine the cylinder end face and diameter, and then the guide bore. It's a plan.
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A little bit here, a little bit there. I finished cleaning up the feet. The set up worked well, I'm very happy. The feet are flat and co planar within .001" which is plenty good. For anyone who wants to try this approach it works very well indeed, but don't even think about trying to mill those feet without some hefty supports. So the turning option per Stan Shire might be a bit easier in a lot of ways, but I was nervous about that. All in all, glad I went this route.
(https://dsm01pap002files.storage.live.com/y4mgTTg_NA4SvX_PCs0j8fRV3ivb0oJ155sds6HMRK70u-LvHg1DjKAEg4W4bc6RNwX305iJKjsaQ_odQEGHIs6nSIaMf2t-eIciQ-dMVZPgPauNKFBweO1wTHl9nWTKdQM8fR5xWnz0G9YvNTjdfjS6V7bIgpnFafwKRzkhQwDXblUERilf00zSG7jP-WsihkI?width=768&height=1024&cropmode=none)
Absolutely no sign of any rocking when on the surface plate, or when tested on the base. :ThumbsUp:
(https://dsm01pap002files.storage.live.com/y4mOU6xvDegPZseJd_rbcve7mrHh9xkOq1VCj1Cy0BAwbtProyD6vfPx67FogGbwIp8lR213Glg9rLxagGt0lFP5wZt7mEzsIy0ZMgF1d5WPWquqwlenLaw28IiL6dE5pj5HwcG1z9fy1STwv5vBHKNkL1RPqHaf_M5tSd86jASpsFY8fGZim8jzVZKaG6GcJgZ?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mwWjvIZBHhwsREyADi_qNh6Ox3_8vw4jk0iLSoIbyl5RbKeF4KT_uK3QXihs6m87BnNlnxJ0nZ7nGIwcFoWbz6mNnqO0hkDw8mXRbGwWuIByg7qwEE2GxDAXItV3IFaL89QB7nliR5gqk0UWMjKHmvLe5xsPNXgCGIxweOE5WZ2QaoVnuPI7nV0TFMrKmslT6?width=716&height=1024&cropmode=none)
Now giving the faceplate a light skim to get it flat for the next gripping installment.
(https://dsm01pap002files.storage.live.com/y4mtvr_RJAD0XqDroJK31uGbP-TABRIeENCs8ReMpxO-Z0xax320W6sNwJuh9oW8sgrBmnbxBNiTp9JSzfOEopW3eYha-xrdcMenMgZ4trOYi4vHNqRFIdcEvN2X59vWCVc9nKMnkQRBm_rQyiYSfh6BtRmBQ8xaRKlm48NT_7_CV0T10femD8c0anvGbZSn5UA?width=1024&height=768&cropmode=none)
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Well done! Long legs like that are tricky things, great setup
:popcorn: :popcorn: :popcorn:
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Yes! Very tricky! You had a very solid setup there, well done! :popcorn:
Kim
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Hello Stuart,
I might like that steam engine too. You are very good at machining the castings.
It's not as easy as the A-stand on a Stuart 10V. But as they say:
Many roads lead to Rome.
Greetings Michael
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Thanks all, thanks for looking in and commenting, much appreciated.
I had some fun this weekend - made a little more progress.
I finished skimming the faceplate:
(https://dsm01pap002files.storage.live.com/y4mY-BMu7RHxbSGlarC1WxLgH8mn_zl-XEXamxaFPDtrevaaXuh3d9BZRjgaGZj96OPnxusr5K-t7ukByg-ZY_YT5IcUwr8HcEBObvxpcJPteYSn3qkRSe1VqEuhOU2fTvMewbFHJpIH78ey6U11ZMNP1q2JVJvThpDrp8SYD0SsoFH9QbFHQ-xxFa_Sovn709y?width=1024&height=768&cropmode=none)
Then I got the frame casting mounted and trued in. I just used my fixture from the milling to get the as cast bore mostly true, then spun the faceplate by hand and watched the external features to make sure everything would look true.
(https://dsm01pap002files.storage.live.com/y4mWuMy8YIg2JLmVlBmcZtM7Xz-ZB4SwO7Ak8nP_x_ShhbPuNuDUuRyrXRuHwSctGIB3NOL4YW86V_GI-NMpLX7wgpYgpHHWLgT9z1dd2WH0Ahgv-bAPuwh2ovrdycg_lnv8W8F0V5_IDBjNgtgLLRLNMdOj_3PJ3Oa6MYXh-AHw-Cd18T5UkDdSThq-hDNP7of?width=768&height=1024&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4md3falqWLf5lhBxb9MG30AOEJwEBK4aMmDSm9nuGNrHEC1BPKowi3VBRHuVLJhH1CfDBnNVbNFQGRafdPjswFN5BbFIw3AE2_vZZtFwxU8B85rz8eQVuuex14fur-Lko8sotQMzjOeh_kyZOJ9QfLs8LcOjyOE0ZCUeYy7SXe8Do0ExkyAsRMRyVgFSouWG0U?width=1024&height=768&cropmode=none)
I needed five pairs of hands to get it all set up, but got it there.
(https://dsm01pap002files.storage.live.com/y4mtYAyPEzgnaQqewGulFJ4XoniUGXEKxvwIsLu7oRRhB8oBhxi0WbYnPH2h-tCW7uoHD2wyKM2pd1RDZvDkTy2uzGR84yDtNI1C22yJgEaqu6ByrnBgD2WL1MtV_uyzt3sBAh4SRBNTmVyNgbqywOMdxb3dRgUe7RFcaGMKEW_OMfLNBPbkDv3VFVqvI8926ka?width=1024&height=768&cropmode=none)
Then I drilled a center in the end of the fixture, to allow the use of a live center for extra support.
(https://dsm01pap002files.storage.live.com/y4m9QwdMNroqBsud2k5UGokEEEaYS7vsLF8hkrKSIlP6oZapxaMjoTKeSEQI3ittX15t8u3AWriItCRXQpfqqeg1QW8WhNU9rMs3gSUWTYv_cO90ON1_u1l9pA1F8894YLzQyLTWFuprl6GX5q3MOaRs_CTgq4UQt6Ul3Tvw866JwPiRpll6WYiO50wVlnGM5xs?width=1024&height=768&cropmode=none)
Then turned the head end OD to size:
(https://dsm01pap002files.storage.live.com/y4mN76uYEtPSQNHY7rDMrW3xFrqri_mIH69rUPSChO6AZ4z9TxjPw9e8XAznHwNdnPyOoyQplq4lvVt2flMRMz5_oAO_KSeG6sq5NbGHXfwTI49PS704LAEhW9FFCla6Xb1UvnLvvial8nv_6MdkPTKrAyCb0FGcdk_OOfI-xVhekObWPjPXrhKVcEdWUNyAsjP?width=1024&height=768&cropmode=none)
After that I faced the part to length. I added a cross hole to the aluminum fixture so that I could clamp it to the part, again allowing the use of the live center for support.
(https://dsm01pap002files.storage.live.com/y4mFkfJ0PNHVrCCNPWVz_UJSkFUlKs-ZQb47bumFzxCeknm50QIi_Z3RvK9loHtJMC0RjppdH_ncjqVH_MnaREFNpEiOkaMMjFAS8wwVMGDwA9Rkwnj6_CpQ-htYYeZv4cM3EAYwHcXsTJ86FnaUhoRpb6mU5zyId3umfMfnoIFEVjM4EFyEjrFTrgkCt1ny98i?width=1024&height=768&cropmode=none)
That all went really well - so I just kept going. I had obtained a 3/4" X 10" long boring bar, so I got that all set up and worked on the thru bore. This is just setting up the boring bar and making sure I allowed enough length to get through:
(https://dsm01pap002files.storage.live.com/y4m6eLeQCOTGA7da7I30VHLnnbkNh42I4EEkMRYvZSLe0iNbZBywFy7XjG9Krr9g4zcOS4RmWtSC3vE3NxTtV7Iv9-Rnfff-JaGd7KFtXnGWflxoPvLvjGhuaXjEp3pn79UDsUu_WoOwxyReNpK7Ge3N9jBGT5Ts36_mI0Lj_6JK9u5ABrm2Ktj0XCzoL5RpU1Y?width=1024&height=768&cropmode=none)
Then I set up the steady rest to give the casting extra support. I had to shorten the 3 fingers in order to fit the part in.
(https://dsm01pap002files.storage.live.com/y4mtKSxiv3pmhlkzpr3ID-MVyP5oyc5Wmwe4qvyItt4MuvKq7Y-HxjP2M-bR61yBPyQvcmHgjOBb0Xc_BCAjACN7h6OqXKeFydJ3qjnFiyH3l4FMxyfmHi14wSa0u2Qpirh4t8JO_sD4sclwqo7SZ30FVAjNs133EJi6kKce1AohLvwluedOiRasncGzfO_pKyd?width=1024&height=768&cropmode=none)
Then I bored it out - .03" at a time to take out most of the material, pausing every few cuts to measure the ID.
(https://dsm01pap002files.storage.live.com/y4mFKHuoCcMCuc8LH8jrx4uUuM344TJ3c1q_75pU6EBIXt7Xz0VUmvu8AV2OVepzHJqnvhrR2BWNBqNY5BDbLBpopTqtjveTpB1UFwIAiMzPHewGVZ8AIz3VpEHjXbZFQCSBzBdzGa88GzeuyA054QNwU5I1ZVQMfLW6ydmbq_1_TuXQ6gjabe-QJjZSJbjhW4r?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m88jWu1iWu02DTBB1s6lMm4SlkrTmThoh05iDB02CR69TqbklyGk2udBNygA_8Yp7QtNbiziREgc0kAOZDmee-V-tDjWtwOqjZG8ysd6dS9vEfRg9a0UD-Xy5ArmO2am5x6QcKqs8MKTW8-JWUZIgM7JwaDsrmVFfcYYhbP5tXEziow0AK8TbvkjQXU6U3Gn6?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mPjrZXX3dghMpWMQtgeAT1b8rTv81GDydzYsbPia-PkOpU-GDV6gEEbGAgbB9_d0fO0goDudGNW_AiBFK5ScBWuRQ97rvDhoWaDic6CNWSBdsHnuV7P23fMFLqhe7pDP4-c1GUl53ciqFiuD4dLj97_o4jxCERmZ2n0e81PHtNnDzkSfMCQ7BNNrQRzuim3tt?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mkt0F_dn1guSdBf0ZZ_vAcskO4kPrmjEYnzyttl2ThSNkF9LNWurmSrAYC_KbcIv8FQXCmiSOk6gyn8UkDQps454m9xdl3PCXjLmOps5lKQXuDE5l1-3WZOVW64q5aYLmrDACqWHzCkB-hB5EtvEa9DvJUAnppgpk4uHPrkuSoYIhMusZFqw4QwN4Crc_gVT1?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m1RX2EZIWW2HCJVhs9esHiSNOIhWQ83gc42wNtQZhZz1cGgunZJsq9NADYy7TWEznQCiivXvVGOXl3KuQPEoov_I46PeVDGP_wX44MMLIfpiiVQoeSn_tn2SPKoskMSinZqM8Wtkp09xjtM9fjFDg-QzJaHEBDmG4cCzpdcRc0jqZI_0xxsasxcIVS6uHQBWz?width=1024&height=768&cropmode=none)
And there we have it!
(https://dsm01pap002files.storage.live.com/y4mxSOtC_yas9Lv-tYaA2JL1O7nERzGzvjb6LGobx81cpLr5K-4TjU89Q3QJOqDBMVgf_uO2BQDHuyYjX_8wCkdrjFyR1q6CYyRDClxJLsCLAGA6YFLsXxQ9R6TxShDRMQ_ZSW-Z4S3NBjeJMipq0YwjOXFhXfV2aN2Jc4t_OzgihL0PVG9zlPnpARH84a7WehM?width=1024&height=768&cropmode=none)
So far so good. The bore came out a little oversize which is annoying - that was due to my not allowing enough for the final spring cut. That bar flexed more than I realized. Lesson learned. This is OK since I will match the slider to the actual bore, but it's vexing because I am trying to hit tolerances, which I am doing very nicely in general, but this was a new situation. Should have tested the spring cut while machining out the stock. But I know better for the cylinder.
Anyway, there we are, progress and a very enjoyable shop session. Next up will be to add the bolt patterns to this part. :ThumbsUp:
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Stuart, I like your process! I think it worked out well for you. Those parts are tricky and IMO you came up with a great process to get them done.
Again, great work!
Mike
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Thanks Mike! I feel good about how this is progressing. Thanks for your kind words - it means a great deal.
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Very nice setups, Stuart! I really like how you did this, and how careful you were at each step to get a good solid way to hold that spindly casting!
I understand the chagrin at missing the tolerance you were aiming for, even if, in the end, you can make up for it. It's still frustrating.
But the part looks beautiful! And nobody will know. You'll even forget once you see it all running!
Kim
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Hello Stuart,
I thought long and hard about how I would have done it. But your way is perfect.
I also know from myself that one gets annoyed about a mistake for a while, but that passes 😁
Michael
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Thanks guys!
I am doing a much better job of thinking through the set up process, and also understanding the starting component / casting than I did when I started in this hobby, so consequently the set ups are working out a lot better. I'm also having so much more fun with it. It was really enjoyable working on this over the weekend. I have high hopes for the finished engine!
Although I'm still miffed on the oversize bore, I am very pleased with how the bore is perpendicular and uniform to the end face, and how the end face is parallel to the feet. This will all work very nicely with the other engine components and is how I aim to get to a smooth running engine. That's the goal anyway.
As always, thanks for posting, all comments and advice appreciated!
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Some more shednanigans today - and got the frame finished.
Bolted the frame to the table, and then swept the OD and the ID to find the center. The ID and OD appear concentric within a few tenths as best as I can figure it with this method. I could not readily measure runout of either one, maybe a half a division on my indicator, so 0.0002 approximately. I'll take that I think, given that the mill spindle is likely not better than that anyway.
(https://dsm01pap002files.storage.live.com/y4mjINbWPWJ6n9LQhgD4wUpz6-dOYaKR87zoj6rHCEsLVCyWPdVbraNikTcyuXeNDKb1zE7Vp77VlEQfC7sREPgUN8RYcIwn6K3M7CWBaQfJoGAsWBhqazRPReWye1w1AHglyK9X2hWEPA1leOnewu6D7ygUp3T6y1057nXpBslrwh1IrfzsBLXfGp8E5T7jZYu?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mYWiwNahgO6igPN6zQUU8frlAArAGYtvjEJElYJWvoHYF8Gl6OcPcb7zBTYXxnXSaFXcFFYyvN95YoSsxNMD_GLJ0FkQRkkX33stZV9-lGViMS1bi4EU2PjWEZjZwhci19LxWkEJMFsVvVV3JS-p4bfxu_maEqZcfK51kB9JKpDxj_VzMhQvAbRzG3xcAUZDl?width=1024&height=768&cropmode=none)
There was some balancing to be done between the bore and the outside features, squaring the part up, and then I took some reference measurements from the DRO on the feet, so that I can set it up the same way when turning it over to do the feet. Of course, what I should have done when I cleaned up the feet was dusted off the outside features to make a flat reference plane for such set ups. Didn't think of that until I was done drilling the holes on the head end, but what I have done will work.
I thought I'd make use of the DRO to program the bolt pattern.
(https://dsm01pap002files.storage.live.com/y4mpjetNntTbLqz8-i0CRtKmME7FBeH6LcEenZ7JPqr-qxyr4AekhLW9AZTbOjgwePAB2eMGQVbrjkH6e2AsiF-hugX8LZHpn9CGX1XQmp53yrewR-Ma-WNQM7KYg0jJib3bZKia955drVCnm2i4biPPhmO14ZNTtoulJ3CdO9N1XO4S8SlPvn_vpqLrJmJqken?width=1024&height=768&cropmode=none)
Very nice graphics on this model for doing such features.
(https://dsm01pap002files.storage.live.com/y4m4vlz-E6CEhnGAX823EfTEhLfyX2hCVRGBQCfBK4K3-IRLWEQe1nJ-_5GAGoD0xYmhvv33hVhh-mM-m-vap0_Pqlc1NdbM1RPyFd7o_FeQz8xWy04wlO66Dz6j_-C2sHR1TERvPQRhAlKoeVFiejB8mQmZbQ71DecG-d-BsP_ECGmHhnvh4l2Y6NinhgMakak?width=1024&height=768&cropmode=none)
So that was all very well, but when I looked more closely at the drawing I realised that the bolt pattern is not actually equi spaced. Glad I checked before drilling. So I abandoned the bolt circle program and just went from the linear dimensions on the drawing.
I didn't quite have enough clearance to make use of my drill chuck so all holes were drilled using R-8 collets.
(https://dsm01pap002files.storage.live.com/y4mJaNGLDSi-J9e27uX5fh0U8B08tDJBjWZJUeU3WntC2EJqj7yRggQ6zU0lDpNZdV2B3UK9EEvzFECNHPRvdFR9LQ7l8R3NNiaoK7QaUFaThyfD2X7NX8Wd9IEsgAw4uOUDSyvbKBzuLcmLvXOwNkMnQ2lOoyFB_Bo-UZpByQG3AgPpFQ8s_Gl_cZma9L-gYNy?width=1024&height=768&cropmode=none)
Then turned the part over, balanced it to match my earlier measurements, and then found center. This time I could use my center finder which I find is a bit quicker than sweeping with a test indicator - although I'm sure that's a matter of practice. However - this tool is just a lot of fun.
(https://dsm01pap002files.storage.live.com/y4m5pd_6O_KE9I3Y-Pp1Ro3tY36X_7yT2-DSo-LfvdPGFP6iQC2j8dKmQvmtz2L0QhlBWWemm_HL2IVWbdabkqCnasttebG9QUCI8ngrTEzlQofIJ08hOGo897jo1nTdNdRFZihMFqEPIgXwJAxNnH31N_B3PyFkn7ReNRckZ6qpCXPOZI9UoDtBTxIlWHxNNpj?width=1024&height=768&cropmode=none)
Anyway - then it was a case of drilling out the feet to match the drawing - 4 1/4-20 clearance holes. Simple enough. The PMR drawings give pretty generous clearance holes for everything, which I expect is to aid fit up later, but I have opted to use more standard clearance holes and keep things a little better aligned (as long as my machining is accurate enough). We'll find out in due course about fit I guess.
At this first stage fit is just fine - the screws went in with no binding at all.
(https://dsm01pap002files.storage.live.com/y4mOMPSdYjbfqN-hOdAvP9Sr4euorYnKMGqW2MfEaQRW72bYYBs0DSDvu570vhK2EaI_DR362k0d1kcbnpR7Q1Bo2jrm0ZUPsKka1KncKZwkPvLDf6WXS1yeHNZvgBO4xEtZsefy69jFLnBDmrYGYxribCSAsLgW1IFf98otszitG81fgHYxYwM87GlRepHVEb5?width=768&height=1024&cropmode=none)
I intend to make studs for this engine, I think they will add a lot to the appearance of the final build, but I'm using the supplied fasteners for now for fit tests.
Now to decide what to make next. I feel like turning some things, so maybe some of the glands. Don't know - need to peruse the drawings.
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Looking great Stuart
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Nice progress Stuart, I have been enjoying seeing your setups and thought process.
Dave
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Impressive work - that engine is so much bigger than I'm used to, and the long legs must make things a lot harder. Well done!
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Thanks all!
Those long legs did present some difficulties. As chunky as the castings are, when presented to a cutting tool those legs have a lot of flex. Left unsupported it's quite amazing how much they move about. Bolted down that casting looks like a bow legged man, kinda sorta. :headscratch:
I might be laboring a bit on some of my setups, but the results seem to be coming out where I want them - and I am really enjoying making this engine, I am having more fun in the shoppe of late than I have ever had.
A few fiddly bits today I think, then I may start work on the cylinder.
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I might be laboring a bit on some of my setups, but the results seem to be coming out where I want them - and I am really enjoying making this engine, I am having more fun in the shoppe of late than I have ever had.
Getting good results makes it more fun. Getting good results in machining often means much more time is spent in prep and set-up than in actual execution. Embrace the ratio! :cheers:
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I quite agree Ron, it's very fulfilling when the time put in to set up pays off.
So by the time I was done with video calls to my family in the UK it was a late start to machining today. Fine with me, I was talking with my Dad in Scotland, and he also makes model engines. Our calls usually consist of a good hour of holding parts up to the camera and discussing set ups, it's great having this technology to connect us.
Anyway, I turned a few parts.
(https://dsm01pap002files.storage.live.com/y4mPk8uYxKh1TFBVf3jCBDnxyUdhjG-_GijFOZHg12S-4aKDKshuj7fVwD5mDqAxc0kldWryiOuZKV3y1OU3oDHvOqsX9rhiIoc0hD5hSd0kT1NjzlsN7Y3ZF0tBqAdAfxi0SZUTD8qpFciV3QY_mW9l2jEsxyBoNEj9WicYPLbKhnLrEAbdbIurJ0wNUJ4ezor?width=1024&height=768&cropmode=none)
Nothing too remarkable there. I have finally learned to chamfer parts on the backside before completing parting off operations, which saves trying to grip awkward parts.
(https://dsm01pap002files.storage.live.com/y4mJJe4zgrsBjW18aLLf68zonyNLkNZsvyTYBfGN_bt6q5hBVEiEaVgjsdXE9hzDKOtVm2hgzMqaWWfXKqYtHhGKRRt58lRDKdrdAWfuzk8fw22sH-iQNMkGKrDRF6slMdalUPnrZeR80inonw3kuznXlfEvNrZ49ua73htGjqQKWz899zeYTiI0fWYsWUoj-XL?width=1024&height=768&cropmode=none)
A neat trick that everyone else already knew! :Lol:
I've been measuring up the cylinder with a mind to starting that next, but there are a few challenges on it that I haven't worked out yet, so I made a start on the bearing blocks instead.
Now, the bearing cap is cast as part of the pillow block, which is handy. I think I will leave the caps attached until some of the features are machined in - that will make holding them a bit easier.
After measuring these, I discovered that there is literally no machining stock on the underside of the cap, but they need to be skimmed flat. I decided to clamp the castings to the table, and just dust off the top of the pillow blocks to get good, flat surfaces, that should be quite parallel to the undersides.
(https://dsm01pap002files.storage.live.com/y4mTYokVCOaEjMdg2272Q_gdwSyS6jyUrAbL9GmjAMxZtn561U_BtxOXdUvKfWjL4ww0dbQ3YxMuz-Qdg0JpOkPCPsXQBLzm194GEVN-6vwA9XwkWQdlXzwhjHNkSVIvPnnhypy3cK_DCHGuimGxLaArOMFcAe7IiLz-NE20bduOvHRqqNSIfRNVH_n_kWHbmGi?width=1024&height=768&cropmode=none)
Just .015 removed.
(https://dsm01pap002files.storage.live.com/y4mOD5cGF5LxRIL5xt_em38z-crZPZP6aPeo8DoIrQPYha5DlnTng9ZmObU2e25tK-qQfUkwACyE1eqeKzYkl5slj0M_JkrT3Eb2_zCgNBjf4-vrhDb03G3bFHq5xBCxogrO7l9Qdtn6Hfsj1xMkLlL1V7HMLP9B2r6HtczeSYTZS45fFNNRP1JCHg3zSUcAG5B?width=1024&height=768&cropmode=none)
Then I set up the vise (getting good at getting that trued up quickly). I use a piece of scrap spring steel to hold parallels in place.
(https://dsm01pap002files.storage.live.com/y4mUwh9-hHBhmnV3dAasJQF9JTcH3VmJq8q2bmGt1TxpBT8DLaYQgVW-S1Nq6MZfE7cv3BTgfIFMNZ2_bxDuuS7vafi4IslvSSD4uGfGwsK1KV_QaSKL99TEc3P8r6fGhMqLDDPsMXNwFJ2OJFAhbWsM-LWRn14r0_wcuxF3TcVIIL10JnGSAQpZmnifuEBg4gk?width=1024&height=768&cropmode=none)
I clamped the castings in place, and then touched off on multiple locations to get a feel for the flatness of the casting surface.
(https://dsm01pap002files.storage.live.com/y4mA_NWmRBEs_4jFblcwydKXS7jiusd83Taeu0gnADaNbNsoc9eoEym7kszVVvuZGM9Suv3ZiAIAyAG08d6dLdh6jySLbpDwh50aDXWIv2KTGOtYQzSFkL_mVwgrdFd9z5L4fBAM3O9JIxtYKq2A0WfpQtLARvTvbDSUrZ1a0eyw_Ctn9bniWxiqlQFHNDIqR5z?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mdhosKfLhQZTddCuuEsFXIbNhJuG_jVlIKH31KJ5StggCEoQzTqTSlzBWoQklc3LBqUudh2OYcOjy1jo33veWBJDzOkzE6RXwz6tO2HgOSDMmS6sh40erlG9w-u7l-8SnB3a4tNaH2BsO4aJtq6yXpgfPjgqqdvNgIKXTjP-lEX589DOa-vzHu5gdekAmI2dK?width=1024&height=768&cropmode=none)
Amazingly the variation is about 0.012", which is pretty impressive really, and that is all that I removed from that surface.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-C9Lqrbz/0/a680d315/XL/IMG_6515%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-C9Lqrbz/A)
As you can see, the stamped in part numbers are not quite removed, and that's fine. There is also a little roughness near the casting gate. Again - unimportant. I can't afford to remove any more from the bearing caps and maintain a good appearance, so this will do for now.
So that's where they are at - next phase will be to get the pillow blocks to the right height ( plenty of stock on those - .079 left to go), and drill and tap holes. I think I will do it by clamping these parts to a flat aluminum plate, so that I can put the through holes in the bearing caps in place in the same set up. Then I can cut the caps off, clean up flash, bolt the caps to the blocks and machine sides and get ready to bore the crankshaft bearings. That will likely be done by bolting the bearings to the base and boring through both bearings in the same operation.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-f46RHNT/0/f622a9c1/XL/IMG_6517%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-f46RHNT/A)
That aluminum plug in the lower half of the picture is a plug I made to test the bore in the frame. The bore seems to be quite straight with no taper which makes me happy. The plug also serves as another means of verifying the ID before making the slider.
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I use a piece of scrap spring steel to hold parallels in place.
Nice trick. I'll remember that one.
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The banding straps from crates is ideal stuff. :ThumbsUp:
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Latest part here - lower valve head. It was supposed to be two parts, but the second one got screwed up because yours truly didn't pay close enough attention to the drawing. :facepalm2:
Anyway, a few shots of the process. Not much to say about it - the key feature was the backside step diameter which is called out at .624 +0 / -.001, so I was keen to hit that. That diameter locates the valve head in the reamed valve bore, so I was keen to machine that in the same set up as the reamed thru hole.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-pp6hfBc/0/6f27e2a6/M/Screenshot%202022-04-24%20115921-M.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-pp6hfBc/A)
So, simple enough really. Clean up the OD, turn the boss for the 3/8-24 thread. I added an undercut feature at the back of the boss for the thread to run off to - cleaner in my opinion. Then I elected to use a grooving / parting tool to make the .624 step. The thru hole was of course drilled and reamed as shown on the drawing.
Clean up
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-4f75vXq/1/2d669516/XL/IMG_9378%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-4f75vXq/A)
Boss
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-2Qf5Dft/0/d50b9a7c/XL/IMG_6521%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-2Qf5Dft/A)
Undercut and start of the backside step. The backside was opened enough so that I could get my calipers in there.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-FFbhHjG/1/3ec3beba/XL/IMG_9380%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-FFbhHjG/A)
Finished backside step prior to cutting the thread.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-bPjbgkx/0/5f7cf5a8/XL/IMG_6522%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-bPjbgkx/A)
Then over to the mill for the bolt pattern
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-rTRLQnq/0/b9ffee90/XL/IMG_6523%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-rTRLQnq/A)
Which I located using the DRO bolt hole function. I rather like that feature. Alignment to the bore was achieved by using a gauge pin to find the center.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-VH78t7p/0/7f539e4a/XL/IMG_6524%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-VH78t7p/A)
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-4kdBsC2/0/e61d1551/XL/IMG_6526%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-4kdBsC2/A)
And there we are. Not a very dramatic part, but it came out well and very accurate. Every dimension is within .001. Decent finish too - the way this steel cuts I'm pretty sure it's 12L14.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-t4mg4j4/0/125937be/XL/IMG_6527%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-t4mg4j4/A)
Out of time now unfortunately. Shame about messing up the other part. It would still work even with the one dimension off but I can't have that, have to remake it. If it was an expensive casting I might live with it but since it's just a matter of a short piece of steel round bar that I have plenty of - got to do it over.
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Great Job, I like your set-ups, and the spring steel idea I will pinch, :)
Did you single point cut the 3/8 thread?
Thanks Gary
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Thanks!
I used a die for this thread, since I had one available, although I wish I’d single pointed the thread, just for extra sense of achievement. My threading tools are all quite large though and won’t get in very close to the shoulder, so I need to make one more suitable.
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A couple more parts made. Nothing too fancy, so no need to do much description.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-hqCRsZB/0/7830f16c/XL/IMG_6533%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-hqCRsZB/A)
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-CNx2DS4/0/89bd35c5/XL/IMG_6535%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-CNx2DS4/A)
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-4gjnJSB/0/991425a4/XL/IMG_6536%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-4gjnJSB/A)
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-2MQLNb8/0/873e6362/XL/IMG_6537%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-2MQLNb8/A)
I think I may get back on to the bearings next, that will be a little more involved.
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I thought I would quickly make the eccentric.
Well - quickly went out of the window almost immediately.
The process started easily enough. Skim the OD clean, then use a groove tool to make the diameter and rims.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-FRj3bCT/0/80f1aee8/XL/IMG_6538%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-FRj3bCT/A)
This cold rolled that PM Research supply has to be leaded steel, it turns really easily.
A bit more.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-9xP9gLf/0/be03a19b/XL/IMG_9413-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-9xP9gLf/A)
Rubbish picture here, but shows the process. I don't know if it's accepted practice, but I started by taking bites out by feeding the groove tool in like a parting tool, indexing over, take another bite and so on, then turn off the last material by starting one end and feeding the groove tool along the surface. Did not seem to cause issues and the part came out well.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-vJ9vV7D/0/f3c7d13b/XL/IMG_6540%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-vJ9vV7D/A)
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-jCgtV6p/0/724ea04b/XL/IMG_6541%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-jCgtV6p/A)
I then moved the part over to the mill and set up to drill the offset hole.
Here I am indicating the side of the machined diameter to make sure it is square up and down.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-9NDS5Hc/0/3f372506/XL/IMG_6544%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-9NDS5Hc/A)
I realized after drilling pilot holes that I do not have a drill big enough to clean out most of the ID for the eccentric hole. It has to end up at 5/8. I have a 5/8 reamer, but no drills. Of course, I could bore out the hole on the mill but I've never done that, so I feel more comfortable boring on the lathe. So - to the 4 jaw chuck.
Initial centering by eye to get close:
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-xtGPrjC/0/c1d51f85/XL/IMG_6545%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-xtGPrjC/A)
The hole is 1/2" at this point, so I used a gauge pin for final centering.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-9RscgD6/0/1af4dac6/XL/IMG_6546%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-9RscgD6/A)
Then I ran into difficulty. I chose to center on two positions on the gauge pin but I could not get both positions to run true. I spent a lot of time on this, and in the end decided that I probably did not have the part straight in the mill vise. What to do?
After spending some time watching joe Pieczynskis set up videos on youtube, I changed my approach. Since the face of the part and the OD were machined in the same set up, it's reasonable to assume they are square to each other. I therefore indicated the face to make sure it was true. It wasn't - so a few taps got that true.
https://www.youtube.com/watch?v=kU6pVSixjv0
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-t8z95kk/0/24054a9f/XL/IMG_6548%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-t8z95kk/A)
I verified the part was true by indicating along the length of the OD on the crown - I did this with both indicators and there was no measurable change.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-L3bLwFd/0/1bae2e79/XL/IMG_6550%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-L3bLwFd/A)
Then I indicated the gauge pin right next to the face, and adjusted the part to get it concentric - this is to position the bore center as accurately as possible.
I did a few iterations of that until face run out and pin runout at the face were within .0005", and no noticeable taper on the OD crown.
And then turned the bore ID to the drill size called out on the drawings.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-VPqWwRJ/0/794be9c4/XL/IMG_6551%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-VPqWwRJ/A)
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-S7c677R/0/850c98d4/XL/IMG_6552%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-S7c677R/A)
Then I went to mount my 5/8" reamer in the drill chuck.
Oh.............of course my drill chuck doesn't go that big. :hammerbash:
So there the part sits while I decide what to do next - which will most likely be to procure an ER40 morse taper 3 collet chuck (since I have ER40 collets). If I didn't already have the reamer I would just machine to size - but I've been planning to obtain an ER40 collet chuck for the tailstock anyway.
Oh well - that's it for today.
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I've used that same technique with the parting tool, learned it a while back on one of the threads on the forum.
For the bore in the eccentric, why finish with a reamer? I usually just take light cuts with the boring tool till its the right ID. Last passes without moving the cutter out, just run it in and out to smooth up the tool marks.
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For the bore in the eccentric, why finish with a reamer?
Mainly because I already have it, but that's just being bloody minded. I think I will finish it up exactly as you describe, which sounds like a fine approach. I have HSS inserts for that boring tool, I'll probably dress the edges on the insert and then go at it as you describe, and get just as good a result. A case of not seeing the wood for the trees, while I wandered around fixated on the reamer I already had.
Thanks Chris for the suggestion - very much appreciated!
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For the bore in the eccentric, why finish with a reamer?
Mainly because I already have it, but that's just being bloody minded. I think I will finish it up exactly as you describe, which sounds like a fine approach. I have HSS inserts for that boring tool, I'll probably dress the edges on the insert and then go at it as you describe, and get just as good a result. A case of not seeing the wood for the trees, while I wandered around fixated on the reamer I already had.
Thanks Chris for the suggestion - very much appreciated!
Stuart,
I use a carbide insert tool known as a groove/turn/part tool all the time and I think it's the same as yours. I have one tool that's 2mm wide and another one 3mm wide. I make wide grooves all the time by moving the tool sideways and it seems to do just fine as long as you take fairly light cuts. I tend to use the wider tool, if possible, on the theory that's stronger when side loaded.
For your bore, I wouldn't hesitate to do that with a boring bar. In fact, I do that all the time. I'll use a boring bar just about every time if I can vs a reamer, particularly as the hole sizes get larger. Big reamers are NOT cheap!
It looks like you're making great progress! I'm enjoying watching.
Mike
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I'll second and third what Chris and Mike said. I do both things fairly often. I tend to prefer boring to reaming whenever possible. Not only is it cheaper (and I'm cheap), but I can (try to) get the exact fit I want (tight, snug, running, loose,whatever). Besides, what better way to exercise your newly hot-rodded lathe?
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Well that settles it!
I may have been a bit gun shy after my last boring adventure, but today every cut I made that I finished with a spring cut came out at the dimension I was shooting for, so given that I should just keep going. The finish in the bore right now is pretty reasonable, so with a bit more care should end up just fine.
Thanks everyone for your comments - very helpful and greatly appreciated!
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Spring cuts are your friend! When boring out, one thing I like to do (when I remember anyway) is to test out speeds of turning/feed and depth of cut before reaching final dimension, to see if changing anything slightly will give a smoother finish. Sometimes need to adjust the boring bar up/down slightly or put in a fresh insert - better to find out before that final pass! With proper setup its normally possible to get a nice shiny smooth finish.
:cheers:
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A couple of things that worked well for me on my engine.
On the eccentric strap the print has you drill through the threaded rod connection point and into the strap so that the hole in the strap becomes an oil hole. I moved this oil hole around so that it is between the rod and the connecting bolt. This allows easier oiling and access to the grub screw in the eccentric so one can adjust the timing without removing the eccentric strap. ( Thank you Keith Appleton) Also with mod you can line up the grub screw hole with the oil port and fill it with oil, making it somewhat a reservoir.
On the valverod to the flex joint connection I deleted the pin and made this connection threaded. I extended the length of the coupling so that it had plenty of thread length. My thinking was that as designed you could only adjust the valve position by one thread pitch at the eccentric strap and I wanted something finer. Once running I could adjust the valve position, while running, by turning the valve rod by hand and getting the best running that I could.
These two changes made getting the valve timing and position very easy and for me it was a success.
lg
no neat sig line
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Hi Larry,
Thanks for those suggestions. They are solid improvements and I think I will implement both of them. The threaded connection you mention for the valve rod is a lot like the design on the PMR#1, so I'm sort of surprised PMR didn't already include it here. Thanks for mentioning it. I am also planning on making a tapered lock collar for securing the flywheel to the crank shaft, copying Stan Shires on that one.
No work on the engine last week - crunch time at work on a big project. Lots of overtime, then we had a weekend away. Hopefully get back in the shop this week.
Dratted work. Got to pay for the hobby somehow though, and have money available for materials in retirement. Ho hum.
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Haven't been in the shed much the last 2 weeks, what with trips, overtime and a night at the opera thrown in. What time I did get in was mostly making some jigs and fixtures. But I did get this finished today.
(https://dsm01pap002files.storage.live.com/y4myN8vGBFWq-2CLT_ZBBkc56fHT3rPqekhHjOb3OqV6axHH_LxhNaDRLa5yNQHyvZ0dl8bCDEtUBg4_Zv6-lQWjRj5CijmWI_woToHxg4XVyZoS430Bw7JvpTWjDL-NmTVOuXsms8XRW3lyYwooRFhV6R-Chj4pLKuoYEOdsyMRx_1mh6HG3P1PRkMnqCMP2aA?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4moRYEXiu8hc5x1KhTaf3Ws5jqajbl_kjAYnrxfq35O63gDVW4LDJTyjNVG3WKhORALbo9-2cTidVo4T1BcNA6UrnckEQRiAaT_1-ezp9XzcQqmZ4gMSx2UNbLy4feHSK3LEetnTzpYZle7-f6QFdEezAqTDTUkZTkpNAqL8YtJ9x87giBLJkeA4XV2IMHjkAW?width=1024&height=768&cropmode=none)
Not very much to say about it. I have plans for more interesting parts in the coming weekends, so I'm looking forward to that.
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Back at it again, and picking up on the crank bearings.
First thing was to get the blocks to the correct height. Touching off with a DTI and using the DRO suggested about .09" to come off. Easy enough. I clamped both blocks next to each other for the best chance at height matching.
(https://dsm01pap002files.storage.live.com/y4mmSy4iyTvR-WOnPwcqAIexnXTJJXnkq81MXye4UHAmRvqlZoyZyEp88Fo6AkTxowVZqj6AqkD_j-2g91kh03oIEQ3jKXLgF1UhkgPrB_tlmcOD6Z-XfGNr6elPypi-QdgAqDpeMqWlC-l0rwtiBM5NQQ2gm1SQBGBHbaxkrwkSQ4R9gjdaYuaiOHswWnqGNM_?width=1024&height=768&cropmode=none)
Checking the final height:
(https://dsm01pap002files.storage.live.com/y4m5-2VX2EOjwZdYSk5wM7WgTJatj9tUdFSN7aAkeUbmF6yfWw8qHnPrEHDUWHaL60gbFY9Ssoch6Y3QPWFkhVfFCGvZ5LXcdYBpO2yfdHbpK3IQE2oW4jWqCaJk9mDHESUASU7LbyRIpL_k3JDU3QQDMP_j_YDjBZ-IO-njfHs9HG9oCMfSVtKlnFzhhoOD2U8?width=1024&height=768&cropmode=none)
1.375 was the nominal sought dimension.
(https://dsm01pap002files.storage.live.com/y4mbf7h7El3Z6HJCJRHVQV9WKE7UD4I_EZAe5S9L3oiy_FHjXgD54T4B-yYVmNKwX8LGC0Dm4pZJ70Pmo-dBk-4FxHr1Xo4iytIN_4z9YZ9AROl4N2lShapeN62oRMQ5U9lF2xG0xEzM0Wje58O9W6PUGvi3Zwa_8EFrEJIbosTPGiCKzL8dv0X2VoqH5I9PPQh?width=1440&height=1080&cropmode=none)
I'll take that.
Sweeping across both blocks suggests coplanarity and flatness within .0005 to .001 - I'll take that as well.
So then I set the blocks up one at a time on a fixture plate, to protect my mill table. I used a .750" gauge pin to visually align the casting to the mill axes - basically just centered the pin on each boss of the casting.
(https://dsm01pap002files.storage.live.com/y4mtRc0ky2WT6eEnPTpOindvgx7bQlKmKoMdUeymH2Ua7B37MjEmmToJgKC4BRSnU_RGtIBunvdEKIRg-Bm7gB1Sr_NmZb-xhmcjK5pX53PFm1S27Sc7s_MDQ3iYp2tvS6aS4HXWLLA2oOU63DlS2ZVDu0a9V_C63AOsNX9g-0x9Kf7HjUDY3flkMEiOsFTv0WF?width=1024&height=768&cropmode=none)
After doing that I touched off on the front and rear of the casting base, left and right, and showed that the edges of the casting were within about .020" of parallel to the mill axes. I figured that was good enough - I want to get a decent visual and have bolts centered in their bosses as much as possible, rather than have a rough casting edge very straight and bolt holes obviously off center. It's a balancing act the whole time.
A quick look once the center of the casting was established shows that the center point is about right.
(https://dsm01pap002files.storage.live.com/y4mDy1Ia95H7DRi5a8njmzf9TRBKSXt3ggxA4MqfZ_MvS7BqL-QxGPfwaAWQE7eqEq3G2L30bv2yI6Svi04cSJfS70peUilVqjd2sLZpD3oOTI6a05SeEjqdvcQu5Lhw6GusvutS5259ZTw-QjsV4GLR_ceRbd09MEU6goGBgWjjlyAB8XNDr05QG-aWW_lgqFw?width=1024&height=768&cropmode=non)
Then it's a matter of drilling and tapping. As much as I like to make a mountain out of a molehill, and post umpteen pictures per step, I can't bring myself to show those operations.
End result seems OK though.
(https://dsm01pap002files.storage.live.com/y4mKVlDNOy5V_OYESWx8SCFkv6gmnwp3_bqrTs-Q7XVRJLjgZzFaiKPxz3D8ODI_c_mm-itmoLlC01JExTA374qEZjfLcMKaR8HyQ6SGIgdbxjwyQvP4gLKX5JnoGTchDXe8xRoTBTTQiIVYmDa73hEIe_csyr9ZYLRQcW3WQs55dGyE4N3cBCOjtxnVzIKtClE?width=1024&height=768&cropmode=none)
I repeated the process on the bearing cap - which you can see is still attached to the bearing block. The idea being that it is a bit easier to hold the cap by clamping the bearing block.
Again I visually aligned the bosses as best as I could, choosing the center oil hole boss as a zero point. No pics of the process, but after straightening the cap to the mill axes, and establishing a center zero, I traced the part back and forth with the point of a center drill just to make sure it was not obviously off.
(https://dsm01pap002files.storage.live.com/y4mtTgT6FtYE_ZIdukVplSPqDvA6OpjdfhL5SwW9C3AqNG7M8364dmEHBYPUqMJo0xjwxDWuxYEkCPg8aFqVMWkk8l0mZ6m4kOobfbKZiD-fuYOD-rsepcj-76d_jmkbyy8USetp7WQtNnh-WfVENpuYpkNMvV96-z4YbYDI5hHXg3QrqRMYytadzVlPGPBkhl3?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mc6TsH5bJY5xWP-ujP7KFJcwhUvaVnLy67sloiCrHH7UQtz6evMGsqh5zQaXmXxhBhDmST-fWgv23s2c5VxE3fU6MfIbCEj-OQz5xjP0yDv9mItYTLQi2OCeQ6V3Kf_7MYdkXJYFBZzxMex8MGms9RK6fyQb7qQcTW2KcqFmxPUtabu3zqEMXrJrnj3lpJnii?width=1024&height=768&cropmode=none)
After drilling I finally separated the cap from the block, and did a test fit.
(https://dsm01pap002files.storage.live.com/y4mgyS_PjGrcXpeENZNjW--tXZ4HawdHi29tUSBdLC8iXmz1i-KiHSTQ0uFSLpE4wfpUK_KZxtSC2mbn8-Fnwq47ugyP9XYdXid1qcuaC9CuMU24jCeTvYevVZnM9gIQXPCM8ZoT-0XQfS7wOy1M9wx9Yj3-SbUwy78ZRSZXqUGMQgpb2NFq6G21l4-VEjsFSuu?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m_V-gAXLz1wUj4_Y-YeDIzfmqx5ZHrMTRAIB_LJK09hYgNhQn-JIut4p1lwtQWjOaJclENKuuXTdcNIVKPZl-Bw9qCtwe_N9Y5L8s4E3vzTPLuVqgnZ778P3B8LVfUkEheao7eZgBc95aEHn3-z0NhgR1o5ILz4PcKEr-zbBYxe-kqjKbxXumVSuso6uG5MWb?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mPPplXx60wgmCwDFgkmtnbGT4x-5xXgDilZ4bVCSTKAVrmEQNX0rAhtp5-5sWlKUaAzzoDmxQjPueKi0ekP5Xgty6bfd95NpalZUambY5EqgxJzWXYH6apcIFFUGTpH87Z3Zd25DH3pgTZQdwxcMnP79o7iLQr4N3fPJK3oPKqBG1ZNHyQLLvpmYNJyLtR4Wz?width=1024&height=768&cropmode=none)
Other one:
(https://dsm01pap002files.storage.live.com/y4m6D9HxRi7s1cPd7g5TaqccNNIfyINj-vEEgPYGPP0T_gNaSOgrYgqgIRHi2HJ5kJ2oRKPUjz5p5HufOfQs4bh0HnHUuINYhIXb-hMsX_Sv94BCNVKoExZL2B82k4bDm4cuckp1jigdvprmArbNQMtsPRf_r2M95wY8gqpqLaHMoCD_xavZ44blxfsh1PSUHV-?width=1024&height=768&cropmode=none)
I'm well happy with these. The casting edges of the mating parts align very nicely, and everything is centered pretty well. The holes are all accurately placed, so these are in a good place for drilling and boring for the crank shaft. I also have to clean up all the flash now - I deliberately left that in case I needed to blend between caps and blocks - and also need to machine the sides of the bearings to the correct width.
So anyway, that was fun. Not particularly complicated, the trick was to understand the casting and locate everything accurately but also matched visually to the castings.
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Hi Stewart, good to see you back on the job, it is going very well.
I think you got the balance pretty much spot on. Not a mountain, and really helpful emphasis on the critical aspects of dealing with the vagaries of castings.
The bearing blocks are looking great.
MJM460
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Thank you!
I intend to make studs and nuts to attach these, and will likely attempt to make the studs a “close fit” for better alignment. The holes called out on the drawings have a lot of clearance. While I decide what “close fit” is to be in this situation, I may move on to the next part.
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I’m enjoying your build.
I’ve always liked the PMR #4 & #6 engines.
Thanks for documenting it for us.
GT
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Hello Stuart,
the idea of making the screws with a tight fit is a good one.
You may have to do this before drilling out the holes for the crankshaft bearing. So that the lid cannot slip.
Michael
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Very definitely Michael - the main advantage is to holding the caps to the blocks securely and maintain alignment during boring.
Not to mention studs and nuts will just look much nicer on the finished engine.
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I have to either make or acquire a rounding bit to make the studs the way I want, and I haven't decided how I want to machine the sides of the bearing blocks yet (angled or flat basically), so while I make up my mind on all that, I moved on to the cylinder.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-XNxj5ZR/0/072a3c7e/X2/IMG_6585%20%28Large%29-X2.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-XNxj5ZR/A)
The aluminum alignment plug fits the cylinder nicely after filing out some flash from the ID, so this seems like a good way to hold the thing for the first passes to machine each end clean. I spent some time measuring the casting and ascertained that the rough bore is quite straight - within .020" or so - so aligning off that should maintain visual appearance reasonably well.
Setting up for milling the first face:
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-3gqB3bt/0/d97c2eda/XL/IMG_6587%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-3gqB3bt/A)
The casting is about .3" long, so a decent amount of machining stock. I took the first face to mostly clean (about .100" removed).
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-dkhmRmn/0/4c9e6c35/XL/IMG_6588%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-dkhmRmn/A)
Then inverted and did the same the other side - now clamped directly to the table to get the faces parallel. the aluminum plug has done its job at this point.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-n4HRHcp/0/4b6779df/XL/IMG_6589%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-n4HRHcp/A)
The print shows that the circular boss on the side of the casting should be centrally located, so I used my height gauge to touch off between the high spot on the boss and each face. From those measurements, and a measurement of the overall length, I calculated how much to take off each end to keep the boss in the center of the casting.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-VvRDM8L/0/c4c84821/XL/IMG_6590%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-VvRDM8L/A)
So then I went back in the mill to finish cleaning up the faces. No pictures - looks the same as previous set ups.
Once complete, I was within .002" on length (tolerance was ±.01" so I''m happy), and the boss measures exactly the same to each face. End flanges are within .020" of each other on rough thickness measurements. Overall this has balanced out very well.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-6JDRkzf/0/5b500264/XL/IMG_6591%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-6JDRkzf/A)
Then into the lathe to bore it out.
Quick set up to get it clamped roughly in place.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-Bp2RwBk/0/720c002d/XL/IMG_6592%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-Bp2RwBk/A)
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-SHTp9hd/0/ed054cc8/XL/IMG_6593%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-SHTp9hd/A)
The aluminum plug came back into play to get the part centered. The live center is being used just to hold the plug against the surface of the cylinder. Coarse adjustment first using a drop indicator:
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-Bc6XsRH/0/1de22bf7/XL/IMG_6594%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-Bc6XsRH/A)
And then fine adjustment. Same approach.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-rvxPfdn/0/ed74f44d/XL/IMG_6595%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-rvxPfdn/A)
Then clocked the face to make sure it was true:
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-7TVZ2p9/0/757574d9/XL/IMG_6596%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-7TVZ2p9/A)
Setting up the boring bar so it isn't over extended needlessly, and checking the rotation of the faceplate and part to avoid any collisions during machining.
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-zmvDmHN/0/0e895698/XL/IMG_6597%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-zmvDmHN/A)
First step was to get the bore to clean up. Once I had done that I did some experiments with spring cuts, which caught me out last time. This time I determined that I needed 3 spring cuts to make sure that I hit dimension, and avoid a taper in the bore. Having learned that I set out to hit the center of the tolerance range (shooting for 1.500" +.002 / -.000 per drawing).
My testing suggested that my measured bore typically came out .0002" over what was shown on the DRO. Not sure how reliable that is at this point, as using those spring loaded plungers for measuring bores is a little trickly, but I remeasured multiple times.
Final result:
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-N4t4N4k/0/4876546e/XL/IMG_6598%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-N4t4N4k/A)
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-jN9xPrQ/0/b6fdfc83/XL/IMG_6599%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-jN9xPrQ/A)
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-B9ZmLdx/0/176ea532/XL/IMG_6601%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-B9ZmLdx/A)
I'm rather pleased with this - I measured it at 1.5009" throughout the bore. The plunger feels like it has an even drag through the whole bore, so overall I'd say this has come out well. It could certainly use some honing, which will be for another day, but even if I don't do that I think it will bed in quickly and easily.
With that done the next step is to machine out the valve guide bore. I have a plan for it, but I'm out of time for today, so that's the next installment.
Ciao!
(https://photos.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-68n2Krv/0/b26935cd/XL/IMG_6602%20%28Large%29-XL.jpg) (https://propforward.smugmug.com/Steam-Engines/PM-Research-4-Quarter-Horse/i-68n2Krv/A)
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Stuart, the cylinder came out great!
I do have a question for you. Why did you bore the cylinder on your lathe vs your mill? I've done it both ways and to me, the setup is typically easier on the mill and I can't tell that the bore is in any way inferior to doing it on the lathe. i do tram the mill though before boring anything critical, just to make sure the head is square with the table.
Anyway, great work and I look forward to how you'll do the valve bore.
Mike
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To be honest - just because I’ve never tried boring anything on the mill. Figured I’d go with what I had a (very small) amount of experience with. But as I was finishing facing the cylinder I did think that really boring out on the mill would save a lot of set up, as well as reducing the risk of getting the bore out of true to the faces.
I also considered leaving stock on one end to face off on the lathe for the same reason - should have done that really, but it all worked out.
So boring on the mill is very likely be what I try on the next engine. :ThumbsUp:
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So I used my aluminum alignment post again, this time turning the larger OD end to a very close fit for the cylinder bore, then drilled a clearance hole and parted it off to make a simple location post.
(https://dsm01pap002files.storage.live.com/y4mdSSrNK4Y6fYwu-bVLLmN86mAvI1J4hqEAnE00WrqxCoZaNqxRZT-znlBc8H7tYXXVMfaXxeEDeFlYZ6FdJXI7pgrJz42UA6kFXIZhZd2GFMM1-FbzWTfil0qjm92nH-vng8W6En13AdBtqQdCuH3iYKIOpNHPRTmlh_00ktHv__HZy06_c1NIE8UBDWiLIAt?width=1024&height=768&cropmode=none)
The idea is to stand the cylinder up on parallels, locate the ID of the cylinder, then touch off on either side of the casting at the X location of the valve bore, then balance the side to side measurement to get the cast valve location straight in the X direction relative to the cylinder bore, so that the whole arrangement doesn't look too out of whack when assembled.
(https://dsm01pap002files.storage.live.com/y4mlTg-f1LUOR4pBNxMMlEOo80S1JgShFU2iE1PaUX7UTWVEO3tI_HGIbHVKLAEwk0DQATMhvjzkDezIFnfeKj09rYxbvz-FZ8Ld7D53k8upZOVY6mNyf6-ZoR56XqL03Uz2ixQse88Ti9b19mf1BxY94PCWaKxmlou1DKthiDORxWvsevUNpYc7ucqh840WvOX?width=1024&height=768&cropmode=none)
I love this tool for finding centers. It's just a lot of fun for some reason.
(https://dsm01pap002files.storage.live.com/y4mdtviMq7girfN_Ef15F4FilOOwVnyvelOSey8-Cc9bXVujrBZ-mUVEm-O-M5xs7TIREQgtvV1QcXqvxFB26PFWNS7eanyR-XzLNz-j09Yt6ydZxt9LEcTLY4ElNeENWm036QtLRoyYbfHw8A-NOR-DHRctLFzqG1kidW1V1tzQFMB4PcLF5noF-Hw1ObFTqN2?width=1024&height=768&cropmode=none)
Anyway, the plan worked a treat. Squaring up the part with the bore located on the plug was easy, and I rechecked center of the cylinder bore after squaring the part up. All was well.
Then I just lightly touched the surface of the casting with a 5/8" end mill. The final valve bore is to be 5/8". This was just a final visual indication that the machined bore will completely clean up the cast bore, and look central. I think it is positioned nicely.
(https://dsm01pap002files.storage.live.com/y4myiX_meYxFgkYAw7KlbmO1DDpaMP-9mjHMoqkDkiSTVaj0NXM06UK_CvplJm7RjKEhOGAtGjrsw2qbk9p_8AY1vomln2DPqZHFCNfR659Ee42a0jHgFTcaxx00M_TiOpcq9zwi06U4PH8WbYCII275MO8X4IW5CoQKaDGFAJ7z2yFpvuNzdRFWjsfFjVdkuQi?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mxjkG8i9bPMXSltnYZdQJrFCdt0o3iAHrR5HE0BLpnoYwwoy5XTulGj-fxr-0Un1tEGxRTS3F2aEynZuDdQ9lGjOZwlHxRlgD7BaYvSyTA3PlXZ1kU4PaLkNjURFekU_HNt2lXAUgvFfohW-eV-1fGj1Pumjgs08LpE8UlTH29OObS5Pho7AqqJ9OU04aoKLW?width=1024&height=768&cropmode=none)
So then, on to machining.
How to make a 5/8" close tolerance hole? I have seen some people stuff an undersize drill down the cast hole and then ream it, but that doesn't seem like it will guarantee a straight hole. No, I think the right approach is to bore the hole out. I do have a 5/8" reamer already, so I may well elect to bore close to size then ream to final, or I may choose to bore the thing to final dim. I don't have a powered down feed which is not necessarily an issue, just means the rate of feed is not constant.
So, went to set up then remembered that while I have a perfectly serviceable boring head, I do not actually have a boring bar to fit it. :facepalm2: :wallbang: :Doh:
So I have to procure one or make one. I may well make one to take one of my inserts. Don't know yet.
In any case I decided to make something else today while I ruminate on that.
So, on to the inboard head. This is supplied as a cast iron part. There is not a whole lot of machining stock on it, so I needed to be a little careful with it. I decided to hold it by the boss initially to make cleaning the OD simple.
(https://dsm01pap002files.storage.live.com/y4mTy9qOu4Wl9T5OlKCmGQcZcz3_8XkedzvXAhXo50csxfk4yJbIOoBnh2YtVmYKJdh6Trp6GdDJZDFloaN7YK2YX1zM0_sk7ftb_MLnfIZJw9ZZ6nowtZGfYAOixAj4sA4OMStkQFASpdZ9aZ_UfhkQyp347QT7LG7zCSoHhh6h5-aR6NuT60-f8c-Ddcdsm5s?width=1024&height=768&cropmode=none)
Then turned it around to make the boss features and locating step for that side. The boss just about cleans up.
(https://dsm01pap002files.storage.live.com/y4mF4isiphthlYjXzG3keflOwJ4ckracw4wDZzWE5xzWTwGLP72EcrzPvu_jlgaGrLlDNsqNMrg6za8yFkzHOpLG37a_Zw0XAY61N90ZDG9Q5331IWf3F0UW-AH8-VW72W_yHT3hTIGPE_PEYVWp2idH_FhjMzJ9zxIFIRYpq4VxIALfQa8JmT1R5PoWoRGOO3O?width=1024&height=768&cropmode=none)
I bored out the ID to tapping dimension, mainly because the drawing shows a flat bottomed hole for the threaded part. I am sure that doesn't matter at all, but I was in the mood to do it this way, and it went very smoothly.
(https://dsm01pap002files.storage.live.com/y4mTrtnKQ9vbST3GLNLb0_LFW4aXQewE_HVjm20ItRB1vX4w_qCr0urCbweLu9WhUBkjFWzL6CkC_eec42xLHXDcdcob6aTu_YSu4f9m66irIZMTKrXZdIknC8RXKxpjzQz78DLMYKgQorAdjlAew3bfnUoEWcJq3_FbYUDmqmXQP1Izx1dCW2nKFQlmWtPGDNA?width=1024&height=768&cropmode=none)
Then I turned it around to set up for the other locating step.
I actually set it up in the 4 jaw at this point. The reason was that when I set it up in the 3 jaw, I could not get the face running true AND the bore on center. It was 5 thou off, which would mean that the cylinder would not be concentric to the bore in the frame, by an unacceptable amount. I think it's the geometric relationships that are easy to get caught out on, and I strongly suspect that is what caused binding on my previous engines.
Anyway, getting that sorted in the 4 jaw was simple, by checking the face of the part for run out, and also the bore (by use of a tight fitting gauge pin).
(https://dsm01pap002files.storage.live.com/y4mFy88t9yHpXQi8xCgXfhTIDn-nPW6leygHulwRTAtO7y4KaRpytTaiq1aLMhZIUNPB-K_2a9JpJIZJXtdcp5MyoPk6T4QSi_PxKflxziKoe_TG6rmv1yLQFy9b2272w7La5Q5TshcXKE4tN88KQOdl64h2PtMtdgOs7CeMysqMgTFW0G0mNSWlzxEWBbD7dsI?width=1024&height=768&cropmode=none)
A simple enough job to turn the step, resulting in a very pleasing fit to the cylinder.
Then to the mill for drilling - this time knowing up front that the bolt holes are not equally spaced.
(https://dsm01pap002files.storage.live.com/y4mMKh2QgCwCRgSE7CI5rDSTqNpxSfBe121kpCu5l4Vee5mhAItT9tCYWDzue8FmF0WaPT6YHSMy5O6iLeO-9Jm4KoJtks1f1zACm3qTTRCAgZM5pKgi6TqD8S_3dhab4pVeJsoSVCLnaC_g9t8Y52rO5YU17qouRnqDL2decdGTiY9IxD8eCdRxuWN7Bj4nXbw?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m_24LqACIScwofieGERUysDSwBFz9WF-ZgCoEnOtvKeGS9jEgeJ3vDyuvwnouXhzNtR8CJDRP56urP4zLnb73Q14izdwhBuOxWHVThAYUdEWBuFTjF-nnw4CgXXiKWYPA46UtJQOCXkSlG0f9gAaXI_qEfQ7uGqzODnFSqby-ZZrNE5L3PmI688lbrR0P3UzY?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mcMXtCuE9i2W6SbOftAWsNn72tLsGhhKBBM2flakc4Da6h9KwerR7_OTVJqZGTkaty_uLij86V06jVVcVCOL6MmYToLp0FEBGm66mTyepI4sLnL04LF-utgzr-CQZ-D1h9lC8aymnIA2bqAKw_pLegeqT6rwtWyDoZemknM248yH7gIUIhQz-zmS5N6V8mTb2?width=1024&height=768&cropmode=none)
I made a part correctly and first time! No rework! :whoohoo: ;D
Very satisfying.
So that's today's shednanigans.
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Incidentally, the irony of not boring the cylinder on the mill, only to choose that approach for the valve is not lost on me. A few set ups could have been saved.
Hey, if I was good at this I’d be making a living from it.
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You're doing some real nice work, Stuart, whether you like to admit it or not! :) :cheers:
I actually set it up in the 4 jaw at this point. The reason was that when I set it up in the 3 jaw, I could not get the face running true AND the bore on center.
I don't even own a 3-jaw, although I do recognize their convenience. I much prefer the 4-jaw, or collets where appropriate.
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Thanks Ron I appreciate your kind words. I must admit that today, after installing the 4 jaw I did admit to myself that I would be better off just leaving it in place and using it as standard. With a bit of practice and two chuck keys, it does not take long to get a part centered.
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Nice work Stuart.
There's something so exciting about the machining of a cylinder!
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So then, on to machining.
How to make a 5/8" close tolerance hole? I have seen some people stuff an undersize drill down the cast hole and then ream it, but that doesn't seem like it will guarantee a straight hole. No, I think the right approach is to bore the hole out. I do have a 5/8" reamer already, so I may well elect to bore close to size then ream to final, or I may choose to bore the thing to final dim. I don't have a powered down feed which is not necessarily an issue, just means the rate of feed is not constant.
So, went to set up then remembered that while I have a perfectly serviceable boring head, I do not actually have a boring bar to fit it. :facepalm2: :wallbang: :Doh:
So I have to procure one or make one. I may well make one to take one of my inserts. Don't know yet.
In any case I decided to make something else today while I ruminate on that.
So that's today's shednanigans.
I chose to ream the 5/8" bore for the valve. It was a couple thou over when finished. My problem was that the material for the valve was a thou or two under 5/8". I did make the valve from the supplied material and in the end it worked but gave a constant leak out the exhaust. I made a new valve from some 304 stainless and 'fit' it to the bore with a tight slip fit. The leak went away and all is good.
lg
no neat sig line
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Funny that Larry - I was making a revised sketch of the valve today, incorporating your threaded attachment method for easier adjustment - and as I looked at the PMR drawing I had to laugh. If I issued a drawing for a part with an OD of .624” +0 / -.001, and issued 5/8 round bar to make it, the machinist would happily come snd kick my posterior seating cushion. I’ll be starting with 3/4” to give myself a chance.
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Funny that Larry - I was making a revised sketch of the valve today, incorporating your threaded attachment method for easier adjustment - and as I looked at the PMR drawing I had to laugh. If I issued a drawing for a part with an OD of .624” +0 / -.001, and issued 5/8 round bar to make it, the machinist would happily come snd kick my posterior seating cushion. I’ll be starting with 3/4” to give myself a chance.
:facepalm: Yeah, the 5/8" roundbar usually has a much larger out-of-roundness than that! :wallbang:
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Update....................
Boring bars were obtained. They were not expensive, and make use of inserts I already have. I've had trouble grinding HSS to the right profile for boring. Getting better at normal turning tools, but decided I wanted to press on.
Earlier in the week I tested the offset boring head by making a 5/8" hole through a block of aluminum. That went well, so onto the real thing.
(https://dsm01pap002files.storage.live.com/y4m4mT5_m_Tq0dQj-WpG3GNgb4Jyg6uXfOQ5Wb52dbTYoRRUAOs7grfQhD-E2zGRv9DI650zKcvEX8njsU34vTCDKjZd2iYBiEur0v7PGbQEiNpT4Pb9gEK7GgvbA60xosOOoVtuczGrQpTNr160jAOVLrc2ruCojYSc-ZrqRN-xVkRB0wwgOGH-oAmAPe-hhf_?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m8q8k0gkvDv5BC4JscvvhWYacNAi2w0dMA9RGaDx4QnYg6n8jDr0Zej-apXDWkC6oPn4Nj-oQg9Cv14jxrZ56L0tcNZHTARsbDBVxfksGjHJQ7rtRwGXCyp_yR7KCobXuJQ7ZnrQrBRCgGLRHk6-nsbm7kdRxENU1YjMffMZ7Z6yVfzY3jnD2OFg7g28mKsiH?width=1024&height=768&cropmode=none)
Anyway - all worked out rather well. In fact, so well that this will definitely be the technique I try for the cylinders on my next engine (A Twin Victoria I purchased from Ron Ginger). There is no measurable taper in the valve bore, and it's right on dimension. I'm very happy with it.
After that, a simple enough job to locate each bore and then drill and tap the bolt patterns.
(https://dsm01pap002files.storage.live.com/y4m-vIPoYDcd318TYCI5_SowlgvxFpYUkvnbWIANvku6NoQOzv_FvU6cpgbLzghFdlukwp5wooMB8o-9m5FvSe7LSZxmdMMYVJg3WKeDySgNkewnHgH-TvG43jKMZgXwmdcZSw6AOCqiwT_vn9MH58AbkZd6XP8ygxSd45dlqmSvhVPXL71OSiD0RQP0MuuPl1e?width=1024&height=768&cropmode=none)
Then on to adding the steam inlet - a 1/8 NPT into the side boss. I packed up the casting, then touched off on a few places on the face of the boss to see how flat it was - had it within about .01" which is plenty good for a cast feature I think.
(https://dsm01pap002files.storage.live.com/y4mHW2TvFeYwOeXariqI-gqVqG53mpFLzey4MlM4aIgY_XSjHKn92V1-yG8cR3PNDhNbqbOQO6CRP1YQqKKOXylYbAkjMqhURAez7e9SjXKLUsU7KcXh-vDI9eXxojQELWZNzPnoxWjwJyhU8QXWzT7991ATNvVYSk1Duq1mT0_WASX8cqb30kQpNEcW-E_ClQJ?width=1024&height=768&cropmode=none)
Then just cleaned it up with an end mill, visually centered the mill over the boss by using a gauge pin, and drilled and tapped the hole.
(https://dsm01pap002files.storage.live.com/y4mLqEXWdhqDfgzbdh94qIJv8RMYYJ8LkWxFAdnXLh7de5oNlLDZsuC9Gy9x8NfR1bb3Ds8cD6MnZPE2fvWmRApzQ2SxubOFE5O7qFndxOuod-XP-1wy8UwhXLdIOWNcRFSR_JuMYHqwEQxW__obugpCoY8_rPb9rLIe6n2sUdb0pk-dRenQF2mZ1xpP6dGqED_?width=1024&height=768&cropmode=none)
There are two more bosses on the casting for drain cocks if needed. I do hope to run this on steam some day, but I don't know what drain cocks I will use, so those bosses will stay unmachined for now, to be figured out at a later date if needed.
In the mean time, on to the outer cylinder head. This is a relatively thin casting, with a raised decorative feature on the outside. A difficult piece to hold. I decided to have a try at pressure turning, which I had seen Joe Pie demonstrate on Youtube.
https://www.youtube.com/watch?v=0DrI5B4hui0
Joe is turning a large diameter thin piece in that video, but the technique is very applicable here.
For this I need two bushes - one to hold in the chuck, the other to push against the part with a live center in the tailstock.
So I bored a taper in a piece of spare aluminum:
(https://dsm01pap002files.storage.live.com/y4m7Gbu0xPRigFB6dzrHC1txhzlc6h6MMD9ThfD0Ig-UG3wD-TsqUZCowMVO8_qMCLgDSPrJGEGHvBWEXGMlUKpv-grCicrI4zkbLkGkxx5uHCbxiN733M8biOwHiLyO4cBgDt3HOvf0dpwQj0msBb5nZ8FXjZxpiZ4gbqVfzvlXI45HSXrzpCHjZf5PsHjtJ8R?width=1024&height=768&cropmode=none)
My picture doesn't show it, but I turned an aluminum bush to a close fit on the decorative feature on the outside of the casting to hold it concentric. Then I pushed the tailstock up against the part with the other bush, and turned the OD. This worked a treat.
(https://dsm01pap002files.storage.live.com/y4mt3Nm6XlQFu3Xn3e1qwd9crskIDPt5pQQNSStTrX4r5afK2fAhmDsf7uGfVcn9Mhz631-bmcb25YxSqqU-tINFh3j0C5ZHlqqj3wYbg_G8TDIt3Uw0GmzxHQbJg0FzbQX_5UPbiM-8weX0a16KsCBjkEVX-vtH_5OG7VQOA6HPiaupLnnFssCX6nXDaysyqn7?width=1024&height=768&cropmode=none)
I also cleaned up part of the face, just enough to be able to clock it once I transfer it to the 4 jaw, which I can do now that the OD is clean.
(https://dsm01pap002files.storage.live.com/y4mYlgyzL4w-mUN3u2xnVwPug3mgTalGLIc8X0bkJmKSP98fpnNjzFabCKGKgANlcWxyrsMkNhdkiJXR4uPP3795SSO2dTR7MKCA7mOn1UvR028WOGhGE9vZS38nRk_B3mmiSRGMef1dMD5_tU1kQfBrPI9fWWPgVSmA6jY49W9XQriDwOjkYSzjElHEyzn0Nkb?width=1024&height=768&cropmode=none)
It's now very easy to clock OD and face and get the part running true, to machine the face and step complete.
(https://dsm01pap002files.storage.live.com/y4m9BpbgOLxz4BzvjQxpm4YNtQysLHN2MYvpF3wi7z76OVvJlW4X26qFUxqueRyaDZk3ACXGZuBfn7SxB11l0bFtKbw_U74GdAF3w39LSoYw6hTrwKSf8j85377eTnl2vUUiRaaX_c3eFuPVT7Jtw0MAB0f-9TnXEy5o7vtkrCJy_w7J67eojDrgi4tfuwkgSPw?width=1024&height=768&cropmode=none)
I've actually given up on my 3 jaw chuck now. It is a very inaccurate chuck, and I can get things set up much easier in the 4 jaw now.
Couple of pics of turning the locating step:
(https://dsm01pap002files.storage.live.com/y4mFbE68aksQGTlvkFolpyW5m1Zr-NudfgPZIrOU8Ll_vpc4nRSvbP57v-fyRBG33ZwUtT-l3nAuX8aONUdUXC4FmWK_0a1yicPGatm778dDSGrzulby8Pvqpj2YGt4zcRQBt-wVRLvRhBH5fEaDtSxSGWxZ_huQxxDS7wDVTiGI39PEnEouvKyt3_ZpAfcm5DT?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m-0O6bxCdpAky9jqCDMwO_VQhydJmFB2GBn3fFdRzQ4O35x38oO3bQiC49zPSamxFjHM_SkmEf9QpBIMLxrWR9eKLWDhsxUWX39BS6tiWhv0LECFxZ4qW66pwZG5s5ce7tWM_PZcVa2OjVrd6GYUuWdvJSKUp_JHj_GD1eMSV9YTx3tk-vA3tAXYtMuEuQL_0?width=1024&height=768&cropmode=none)
Test fit:
(https://dsm01pap002files.storage.live.com/y4mcsnF7JANwBCHsojnkKY4sf2R-xhq3hI7yAfXNugFJAnrXXF_ldUognXTbKL714MrHLy3VDSY4TkA-PjAPkpZO426dDjWefylOm3yNsDghRxELPR9cVmpvIVenOkRoLkaxNYu9NhbXFho-qpcgExZo3C0ip7MqVfo0g3qXBhGAZHS9ebGwugK5n7t7OzU7mcD?width=1024&height=768&cropmode=none)
After that, simply a matter of spot facing the outside, and drilling the clearance hole pattern. No pics of the process - pretty rudimentary.
Finished part:
(https://dsm01pap002files.storage.live.com/y4mFYmXTIEl9osRbj-dcPTRgY0kzGnV5zRCaFgYl_ac12vus0tfmptIiezo24gGQe0NYjZSsvZxa-FrzqETDACZ66cDgye__G_FkIEF3uLQfrA3kEak30_61GCn5Qn53gXXszPKKmX46_WY1iSUc-U8KOkkrf93Ay0v2KFEtYyI0BYBq7EfRUcUZGYf5sJhTfwN?width=1024&height=768&cropmode=none)
And then here are a few pics of some test fitting of parts so far:
(https://dsm01pap002files.storage.live.com/y4m-cx8ktDTOd0upOa-buOSqecClbI31w_d4l3KYmG3ECHvPyEB6v1fQod7Z9QUAhpZ8r4dKgR-iBNDLukfAVOibIDrorEEhvgXpdyAo7gcTsPS5p29Aj9iCHaP993fbcv3PUGp3JJNQe1FDb0gDRzVHe009RBxwVsYIGofPH_MyI8lXtE37ye-z3klORXusNB0?width=768&height=1024&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mIrKb4qBV2NfvkBgljG-L0cUbfsepyXxrnYY1_HC_jNTeeg46smOZebkINlPelU5i45Qm1MvpjwxbVSVubEgLwK4BdQOanu8SpAI8BHZVBUYjXkqKgKlILHRXz9Vbh3CKzOBdc1RiE3BSHnl0ljTEM26w7QNgqCES87B2mDVUZsyIbfEScjBniCu0-5zWWYOz?width=768&height=1024&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mxNbb8iDArOelObtZ4DKuvBpq5OI9ej6mPZnmeq-L5-eLEY9l-aLSryXUrGhWNChw0-cLLyanwBwlStSm3fmZQ4UwIuUCs_Rt8P8MDBVUm4ol_iBsh3eDmC68u_kJn99hAUod_wimMuio79gZ_J2AIcrohYkXEoiLywWUz24Qw3--FCNwSgfBV0MiWs8bObDU?width=768&height=1024&cropmode=none)
I'm pleased with how this is coming together. Things are fitting very nicely - I have high hopes for this engine. Now to get to some of the nitty gritty - up next, piston and valve, and finishing the bearing blocks. Now that I have tested boring holes on the mill, that will be an ideal method for boring the crankshaft bearings out. More to come!
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That big beastie is looking great! :popcorn: :popcorn: :popcorn:
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Hi Stewart, your patient approach is paying off and it is all coming together very nicely.
As Chris says, it’s a big beast. But really looking good.
MJM460
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Thank you guys.
I have to say, I am enjoying this hobby more and more. Now that I have got to understand my machines better and get them set up better, not to mention the processes themselves, the effect is cascading and I'm just having a blast with it. I can't wait to get back in the shoppe and work on the next parts.
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A teensy bit of progress today.
What I have here is part of the long term plan. That there is a piece of 20" long, 8" sch 40 316L stainless pipe. And I think that will make a very nice boiler. Bit of a way off but it was available and the price was right. Like.............free type price is right.
(https://dsm01pap002files.storage.live.com/y4mCnf1Tv8Y8pzMRvh54Il_R6_sLDsKnDwzA_2ZX5McgvPNrK-Yk8VmVju70eYhtCussXu879Qedtpel5zv7-e2DK4KqZYzXAQqd8h9Rwi_XMGCIPqCheULnZgh-PT9Mc2Qhi7MFrPDVaXM9FCiNcSHg92UTmzJcckUYHM0rfl3koyPY7TgjmPS82rVFk0Au2JK?width=768&height=1024&cropmode=none)
On actual engine stuff, I snooped around and found a piece of old steel to make the piston out of. It seems that PM Research forgot to include a chunk of steel for that. I'd call them about it but I bought the kit in 2015, so a bit late to be getting into that. It is also possible I nabbed it for something in the dim and distant past.
Anyway, don't know exactly what steel it is, but very likely 1018 from the way it machines. It's going OK. I'm at 1.55" on the OD now, so next shop session I'll get it to size and put the rest of the features in. Not an especially difficult part, but very enjoyable.
(https://dsm01pap002files.storage.live.com/y4mHpiob0PRgY4YgpfmwxJr-39-X4EudEQ01ISDBKtifI_M7Z5DnUXdg9OPxmvZxAHNKXunOZwoiUM4ldLl8BgVKq3mQNCXsE0le7eX8G8KRx8TqB0KX3yIQit4_0hU0BbbYoFCxKTcLcGPHhiJ3L24X6I1D78GogHmUf-rcVrsf8OAi68vMzKPj8LzFHcvYEA1?width=768&height=1024&cropmode=none)
That's it for now. Not much progress - but some progress, and a pleasant few mins in the shoppe.
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Stuart, very nice work! You've got more nerve than me regarding a possible boiler build. Those things scare me, even though in theory, I could make one.
One gentle suggestion. If it were me, and if you're going to one day run this engine on live steam, I'd think about getting a bit of cast iron bar to make the piston from. A cast iron piston in a cast iron bore is well proven to run quite well for a long time. I'm sure the 1018 will also work, but it might not last or long or may suffer from a bit of stick/slip unless you open up the piston bore clearance a bit.
Anyway, please feel entirely free to ignore my suggestion! I'm sure whatever you do will be great.
Mike
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That's good info Mike. I'll file that away - I'll go with this for now, but plan on making a cast iron piston for the long term. It will very much depend on the success of this engine when it runs on air.
As for the boiler, there is a long road ahead of me on that. Fortunately I have been designing pressure vessels for work using the ASME BPV code, and I have access to the code calculation software so I'll make use of that. Followed up with a full finite element analysis, which is something else I have been getting into the last couple of years. Finally, and perhaps most importantly, I have access to ASME section IX welders and CWI's, who will help me set up and inspect the welds. I intend to way overbuild the boiler, and will certainly strenuously hydro test it. I'm not taking any chances on it! Should be quite a project though.
Thanks for looking in Mike, I really appreciate and value your input.
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Looking through the photos of this build, in page #60, shows you holding the inner head.
That gives some perspective to this engine. It really is big, at least compared to the ones I’ve been building.
I’ve always wanted to build the horizontal version of this engine, the PMR 4.
Hope I have time, I’ve got a couple engines ahead of it, & I’m 74, if you catch my drift.
Thanks for taking us along for the ride.
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Thanks Ted. Don't worry - you're a spring chicken yet. I know this because of your avatar. You'll get to your big horizontal engine!
It is a big lump of an engine. Not the most elegant of engines, but impressive anyway. I'm actually very happy with how things are going. Lessons learned in earlier builds are helping a lot, and the build is more enjoyable for it.
Some of my pictures are not showing at the moment in earlier posts - I am in the process of moving pictures to a different hosting service. I'll do some of the earlier ones now, and by the end of the weekend they should all be done.
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Hi Stewart, I’m looking forward to your boiler build. I do hope that you will include a little outline of the design work up front, and particularly the FEA. I’m certainly envious of you having access to FEA. Unfortunately it came along a bit late for me, all my pressure vessels were designed using a slide rule. none of us had access to computers in those days! And they are still standing and operating.
MJM460
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The FEA is useful mainly for the more off the wall designs that come along these days. It is still better in general to do the calculations "by hand", but the FEA provides a useful extra insight for complex geometry areas of some vessels we build. Where I work we never use FEA as the sole design source, but use it more as supplementary evidence and support. It is certainly a useful tool. I don't really need it for the boiler, because that is very conventional design and construction which the BPV codes cover easily - but I'm still new to FEA and it will be a really useful exercise to model it. Besides I'm doing the design in CAD anyway.
The design will likely be complete a long time before the boiler gets started, but I'll gladly share the process. I don't know if I will publish drawings because of liability concerns. Maybe I can put enough disclaimers on to alleviate that, but there will be screenshots and so on, and for experienced engineers with interest in the calculations I can share those privately if there's interest.
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Hi Stewart, I could not agree more. These forums are not the place for tutorials on pressure vessel design.
Some screen shots of FE output would be interesting though. These techniques allow us to see how well (or not) the traditional safety factors allow for the stress concentrations introduced by some of the standard vessel details.
What ever you decide, I will be following with interest.
MJM460
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Stuart, if you do end up building a boiler, I'll also be watching closely. I have had fantasies of building one myself, but am quite cautious when it comes to a potentially 'explosive' situation! Plus i'd need to make sure my welding/brazing/soldering skills are fully up to the task. They used to be, but it's been quite some time since I've done any serious work in that area and there's a lot I'm sure I'm quite rusty on.
In any case, impressive work! I'm looking forward to your further posts!
Mike
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Thank you Gents! I will be glad to share the boiler project - I'm looking forward to it myself.
In the meantime, a little more work on the engine.
First off, I picked up where I left off on the piston. A relatively simple piece - an accurate OD, with counterbores each side and grooves for teflon piston rings. Critical geometry is to get an accurate through hole to locate on the piston rod, which needs to run concentric to the OD. Also important is that the inner face of the counterbores are perpendicular to the OD. Especially the one which seats against the shoulder on the piston rod.
In the event it mostly went smoothly, but I did have trouble with the grooves at first. I ran into some bad chatter which actually dislodged the piston slightly. Very vexing. I got the piston trued up again, but caused a bit of stress.
Some pictures of the process:
(https://dsm01pap002files.storage.live.com/y4mJeoLeMptDjYflXrvE84gDjhPHi6yXvADuj1618fYMB6KssBXqQLXCJ9inFR0Pqy-mhMO-iqc9OhKzYuTkS5Eq17A5zVDplPtU_q07zLOpvtvV-mLQid7gVapKI7UdPFn87KcNDicJy3J3ujLHYS6tkcrYMY7rU_fD8PHPi9ZCx35xgvEW2IY_JcR9r66a8o8?width=1024&height=768&cropmode=none)
Sometimes it is a good idea to map out where you are going with the cutting tool, so that you can take into account tool width ahead of time and not get flustered. I sketch it all on my board which is above the lathe before I start.
(https://dsm01pap002files.storage.live.com/y4mCd-3uAEFgkx24OBUSSLERICPbNn5dq2O06MKZy8mSUS1pEI5sEBQQYHcIO17Y0l83hHdwcmYfsj5UN9yTsj3u3f6ORWUClpsKrtbeenNczJKvrL809FriyArvbiNYa_5Q2hDvU375SD9xLNGWVVnsiA3gxMC09JHlOiL_7wMpCvWcdoEf6axx1et_kyTEujv?width=1024&height=819&cropmode=none)
Getting groovy.
(https://dsm01pap002files.storage.live.com/y4mMZp9nTLRFWg1OfSQ_ne6iKO3nLf5r1DZp9vMLJzM1bKgm-orJw58bCFOwTtBG7ACJ_XXNCKlYowASahdnJwTH0zk79ndXhCUqmXKgZvU03V_hUgZhN3FSQg9wtkRYiQsv_wN91XLjt_tgmqDpDPmCEu4TKWyii5A4CD2NR-uVLM-HynvaUwT2nvtHBMbC-nO?width=1024&height=768&cropmode=none)
After doing as much as I could in this set up I parted off the piston with about .020" of stock left on the backside. Important - I started the part off with my thin groove tool to make a face to clock against, before doing a more coarse part off.
I also made up some copper jaw covers to prevent marring the part.
(https://dsm01pap002files.storage.live.com/y4m87UFLjosG35MlZZqg0sAKoBkTNGVNmdUjptLLJyUZKJArAcJVVawVlDcsQ2KTsoKIu8we9D95y4EGZtmCDs0bUoWJeyVvGiDvhFDbpLNzTZxBQ6sC5Doxyf-3gruvSoi9Z1PYq-eII4iy9htaYuM6kuQAi8Z_BIaq7MnV_qdZlX6QiyxSNnIfu8tJCo4f0we?width=1024&height=768&cropmode=none)
Roughly centered the part using a close fitting gauge pin
(https://dsm01pap002files.storage.live.com/y4m6DKNPIJ3AmbxQlRVftqrzhcVKe22O9qLJKxzW2N5gciBxjBmuWaRTdVZ_-Ly8z3wrrOFqPjT_JPXuTrwOhmqBwoy-eNaMq2j1zCEQ8WeFVl2ZdBo2c9tESqfVkc8bJAVnV6C3XOXnprFu0XVKU7ZU80DzjzL1W2uAdZCvpVGIzCYJhiynZAZBawDQpg6eYiU?width=1024&height=768&cropmode=none)
Then carefully dialed it in by clocking the face then the OD.
Just a matter of clean up and making the second side counterbore.
(https://dsm01pap002files.storage.live.com/y4m6ZAbkG9FkLuzwdJ3EUav5gdWUMVgU_yhgx6GRhfBw0osP3MNmX5wve66MDRcf2Q-3qh0jlSaroVFCJOzD8h1lDnSQYEc28yvSLUGZgsMKwq0N28GjaR5loaBtZxTwo9zkanXa0jZxOulWz_bstcJMxqkxA_ixNwHFX8uLI-VeH_lMUg3D8EEUUge4w6uOetu?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mfH9boaT26KznLo-agV_Ut_0-4CV6A-rro08Hi0BPUGqdjHsHf6WBxCLJ1hH0ABjniVGMP_eN2vz909fcDPskT0oeFj0ZGHrbJRO7BKlfF0u7T7wXsQXy4nhYJMQFhoHwHJ2ggYtrlLKW6Fbj8V9crHSM6AjPa7Inv1-Yfx_z9vjIswzKm4EMKbXK3FdYFsvU?width=1024&height=768&cropmode=none)
I put a little groove on the face of this counterbore, to reference during assembly so I know which counterbore was made in the first setup vs the second set up.
After all was said and done, the piston came out very nicely. It is a perfect sliding fit in the cylinder bore, with about a .001 clearance. The groove diameters are within .0005" of nominal, widths within .002". Everything else is within .002" so a successful part.
So then I went on to the spool valve. I redesigned this per Larry's suggestion, increasing the length slightly and adding a threaded hole to connect to the valve rod, for easier adjustment.
Started with 1" material (didn't have any 3/4" after all). I think this is 303 stainless. I took it down close to final size .05" at a time, leaving about a .018" final cut, which got the OD to .001" under the valve bore as required.
(https://dsm01pap002files.storage.live.com/y4mNgqcuin5XMvCDWxCHaurkjNIKJcSEogLBuM-W8vBgW2lDP-K9fEAR6wejx3ix9bwtG4Jw5oaz9ULqUwJ9_o3ivkRCQ15BTZRAXWp_yXy1FLusklhg1Vr-yPAtId6XPs9wK2lIJcSEP_OVDzm6Yk_6IM6KYdtOXpLjHhCovSxmVH-WCKsTsJsPruMQMUwx25H?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mrERZCr2-UX00zAbx8AXR-YUpTYTlskjee_Ql01N9oFDnbvogkipxmazRdt06hY5S0BwT09AT0Nx8ovQScVVMvJuk_yW32hoGKrbC9MGTbgoOiTONQNUu91rcP9asxsEMTKnXsYwtnK7YgeQn7mPkS2CmhZ0EIQ8GTl-BxIhmx8ivpQVspAwEoJv8Jj0omyb7?width=1024&height=768&cropmode=none)
I learned a lot about grooving (and parting) during this process. Also, I pushed the unsupported length of the part far too much really. As a result I got some vibration and the finish of the smaller diameter wasn't great. But you live and learn, overall everything went well.
I didn't take many pictures during the process, but it was a case of plunging the grooving tool to remove the bulk of the material along the valve length, followed by a light skim to final diameter with the grooving tool, followed by drilling the blind hole, then turning the part around, aligning again with a test indicator and drilling and tapping the valve rod hole on the far side.
(https://dsm01pap002files.storage.live.com/y4mNmLLwfxMHj82AQsE-TRxrDN3_yAsqlLwx6E_yo_JyPz2TaRhhEPSdGkw3A74TqnYyFzDE4Tla8ueoLzNKIUbo5ht9RzDCJKaddeMr08_RTfu3Wtf0l2yzG3jBUIjJ59jy_n7mjh9JZm3y_sijjrdUG89yCUlJwCqijU0miSX94j-x7gcYxcCA_XQw-cHpyox?width=1024&height=768&cropmode=none)
The parts as they stand:
(https://dsm01pap002files.storage.live.com/y4mW4NTLw7PVNrMZ7HuwTuz5RGEZWSbKWj0pUyXMJVNDvyCzthsED3S-tfTQ258s5uw17j-aXk97drvBt2ku5ZzvQ5dZi1ulXwOHVXjv3EUm1qP-1qnzGVVLB4mTvxahGxppc-sOoi9Q4K20k4s7ze2_3Bfo9D1UIc0Xza1tOKAQsOMRfzMq5cniWFMS2agFhHD?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m4QZlmrw19wOw2l6jP-dTmAJg8ZGmJX6L76DeHNl8Ps1K9CvuDzffMGoT5ziI-MbGF5czoXwGsCTicnG-g31MJhvaa3QJ-rsmQsqVi9tg3Qi_VmFre01k4h_YYw8ar3e5C8dvkX0Vmz_mrdxhM4TBgmATJYehTYUzdhAFurtwHtaBr_en4a0DL2QyZfyH6Ffo?width=768&height=1024&cropmode=none)
I still need to drill a cross hole on the spool valve, but I'm out of time for today. Time to clean up and deal with some everyday matters. Such is life.
Thanks for watching. This was a very fun workshop session.
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Looking Good Stuart,
Good to see you knocking of the "rats and mice" pieces, + 1 for the Boiler Build, I have a decent lump of copper pipe, 6in diameter, I also, want to make a boiler some day.
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Hello Stuart,
I see you've made good progress. Now there is not much missing of parts for the first run of the machine. I find it very interesting and informative to watch you at work. When I see your way and the building of the machine on youtube by the girl who also builds this steam engine, it's nice to see how many ways there are.
I look forward to more pictures.
Greetings Michael
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Baltic - thank you. Yes, important to get these hidden pieces done. For two components that are actually pretty straightforward I derived a MASSIVE amount of enjoyment from them. I put that down to applying some thinking learned in my last engine build, where parts were not as well made geometrically. So I may have talked these two parts up a bit given their relative simplicity.
Michael - thank you also - one of the many pleasures of this hobby is looking at the many alternative ways of making the same parts. I haven't checked on Blondihacks channel for some time. I think she has been a bit space constrained on her particular machine tools, but I did see her figuring out how to get the frame casting machined on her lathe. Like many home machinists she comes up with ingenious solutions to use the tools she has available. I'm lucky in that I acquired slightly larger machines with a little more working space, but it's always good to see another approach.
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Stuart, well, if I didn't have a few sets of steam engine castings lying around, I'd love to build this machine too.
At first I thought the PM Research #4 was a typical American steam engine with its high stand and long connecting rods, but I also found illustrations of German upright single-cylinder engines in a book. Built in the neighboring town of Halle around 1902. It looks somewhat similar to the #4.
I'll take a look at PM's catalogue.
Greetings Michael
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Hey Michael thanks for posting that picture. The resemblance is uncanny - I have to believe that the original engine the PMR #4 is modelled on drew inspiration from that engine - there are a lot of similarities.
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I think these engines were state of the art for factory’s & mills around the turn of the last century.
I wonder how big the flywheel is on the German engine.
I have a PMR #5 I started couple years ago, think I’ll dig it out & start on it again.
BTW, the hen in my avatar, like me, is no spring chicken either.
Her name is Daffodil, she’s going on 11.
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I have a PMR #5 I started couple years ago, think I’ll dig it out & start on it again.
That's a great engine. I have one of those sets. I think it would be great if you would continue with that and post about it, we'd all enjoy seeing it.
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Prop, this is my progress so far.
I made a major blunder when drilling for the crankshaft, notice the scratch built crank bearing caps.
After a couple more mistakes, (all fixable) I decided to try out a few design changes, & use 4-40 socket screws.
This is gonna be a bitsa i guess, i just hope it runs well.
I hope the photo shows up.
Now back to four build ;-)
Cheers, GT
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A couple of things that worked well for me on my engine.
On the eccentric strap the print has you drill through the threaded rod connection point and into the strap so that the hole in the strap becomes an oil hole. I moved this oil hole around so that it is between the rod and the connecting bolt. This allows easier oiling and access to the grub screw in the eccentric so one can adjust the timing without removing the eccentric strap. ( Thank you Keith Appleton) Also with mod you can line up the grub screw hole with the oil port and fill it with oil, making it somewhat a reservoir.
On the valverod to the flex joint connection I deleted the pin and made this connection threaded. I extended the length of the coupling so that it had plenty of thread length. My thinking was that as designed you could only adjust the valve position by one thread pitch at the eccentric strap and I wanted something finer. Once running I could adjust the valve position, while running, by turning the valve rod by hand and getting the best running that I could.
These two changes made getting the valve timing and position very easy and for me it was a success.
lg
no neat sig line
My suggestion above I threaded the upper linkage part #23, not the valve. That way the adjustment happens outside the block. When running I can adjust the valve position while running and then the locknut is at the flex, not the valve. Being the valve is round it is free to turn in the bore.
Did I say before that I wish I had your build to follow when I built mine. Some of your setups and procedures are simpler than mine.
lg
no neat sig line
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Aaaaaaaaah - that makes more sense Larry. Well I can still do that, and I shall. I’ll think on whether or not to keep the threaded valve for connecting to the rod, but going back to a pin might make more sense. Or try it threaded and change if needed.
Thanks for looking in - appreciate your insight and comments!
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I would think that having the valve threaded would be OK. Not a lot to loose if it doesn't work. On a side note the engine will run just fine without the caps on either end of the bore. The caps only ever see exhaust pressure and control the flow path. The lower also provides support for the valve rod, but it will run with out it. I had some fun with the exhaust pipe length. The sound of the engine will vary a bunch depending on the pipe length and mine sounded best with a 1.5 to 2" long pipe.
lg
no neat sig line
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Some days are better than others. I had hoped to have a selection of specially made studs to show off, but all I have for a days work is a bunch of scrap steel.
Ho hum. Try again. I thought these would be simple parts. Maybe I got complacent - pride cometh before a fall and all that.
No pics. Noooooooooooo way. Maybe have some by the end of the evening.
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I cheated, I used set screws of the proper size........
lg
no neat sig line
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That's fair enough. I want to use close fitting studs to aid in maintaining alignment of the caps to the pillow blocks. Not really necessary, but an exercise in precision of sorts. Happily today was a lot more productive than yesterday and I now have my custom studs made. They are .001" clearance to the holes in the caps, and the caps slide over them when they are installed - it's a very close fit, they are not what I would call a "sliding" fit, more of a transition, but not a press fit. Since I drilled the holes in pillow blocks and caps separately, and did not transfer drill them, I am very happy about this - means that I must have the mill and lathe set up pretty well. This sort of precision was always my goal and I'm finally getting there. The recent fixes to the lathe have had a lot to do with this level of fit.
Anyway, I have been setting up the bearing blocks in the mill to clean up the bearing castings now that I have the studs made. This is all, as usual, taking a LOT longer than I planned. Doesn't matter though - no scrap parts made today, so much better than yesterday.
Pics of progress tomorrow.
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It takes time to get things the way you like, the devil is in the details. As far as I'm concerned it is perfectly ok to worry about things that no one will ever see.
Ask me how I know. ;D
Dave
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Very true Dave!
Well, a few pictures of a few things. Not doing a blow by blow account here, because most of this is straightforward. I did run afoul of the higher load generated from form tools, and tool heights set too high, and inappropriate machining sequence on slender parts, as well as too much stickout, the combination of which made me scrap too many of my precious studs. Still, that's all worked out and I'm chunking through them.
I want to make custom studs because I want to locate the crank bearings and engine frame more closely than a regular machine screw will allow. So I am making studs with a shaft closely sized to the holes in said items (I didn't think of it at the start of the build or I would have reamed the holes to a more round size, but no matter).
I ground a form tool to radius the showing end of the studs for appearances sake.
(https://dsm01pap002files.storage.live.com/y4m5J4AbfSZRFD-sMGw8oF4BI3xEuxjW6DExa8VkeY_QBUlnf8wMbptKnljUkmq6eOB_jbKXeDSEYn2HOKwqAx5BTSmhmS8Qo-02OqDZ8iIEoAF7jpakCsF76sN6VOH6e4uFeH6vApKCHoGQ3wRi51pkmPlqRxqWfwykCBVSffFo9MqopFCMjs1Kp9NwsOM3zNE?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mzw2ChKHX5TvKCn97L8fxG0GwVt9Zc3BjdPfee_NZirIOfoyV9CuNYjRdQC_26rmlPzVV39EjQFRkW6BVMzpKVK9s5fK9bahMfmjJH4t5g1PIfLnzuLdLst4mgpxXA2m1JpdjvP431DNnb--vjt3yaFr2NHHCgWdHWDQOwEtC38fOxPkKwQH26jDIWtIyrMgK?width=1024&height=768&cropmode=none)
Fairly pleased with that - I ground the radius using a small round bit in a dremel, and using a radius gauge as a template.
Anyway it works out OK, the studs for the caps are a close fit, so now I can finish machining the bearings.
(https://dsm01pap002files.storage.live.com/y4m2XEJuvMIkS3jSyePG0x7WzV9jYpWoVnPIttCXLm9XHKEeHEkw2soId2UKZrylPr2pXqBC68Gr14RRng_8IEXAz6A3eD0lv7T4jGVySEn9RUmcWtoj3yEA-ZT_maZCR9z4-4SGtHOi836c6FGei5aas-FxbiIk03AcLH4CYxT_V1LwENUM2uk66cqtwUJyS5j?width=1024&height=768&cropmode=none)
Which I am doing here using a vice in a vice. I decided to copy a previous build here, and just clean up the angled faces of the bearings. I think this will look good. Here I am touching off on the casting in 3 spots to get the surface level.
(https://dsm01pap002files.storage.live.com/y4mj1hIvb-3ba_0EkyOapGI1HdY8lr-u6PqYdrW3AyY94u7jlmvE1SdOtKCP2FhZvK_PJ8d1jjJWzclvSD_wuIDm-Hq38i2bengTE9PDpFzKq4r40m0gJIikOKpi6ygPp8v24AnV83KmfXg0A4HTnO0VoUVm3Lw-9HaXI0j4EbvmR5IEm0fU16DKp8NUVQepgfb?width=660&height=495&cropmode=none)
Then skim over it:
(https://dsm01pap002files.storage.live.com/y4mfWdRyXtGS3PHUh03a0FmfG4X-pK2c8RThDOteHx-IkZkilgr3W__r5HE5YaobQ71_iTvg4SlDkncFGtsGQUbcKwvQfW75iK-2JZEgWu8XG6QB4ZDdxbf6i06yFVu05oHq-FSQRnBQxI9iw29sg91IafNqkVwRinBJqmg9Sf37gUR6CPdA3vOLvPrs-wy4-2B?width=1024&height=768&cropmode=none)
A little hand blending is needed now on the castings to fettle the caps to the pillow blocks, and I also need to make studs for the pillow blocks to the base. Work in progress in the foreground.
(https://dsm01pap002files.storage.live.com/y4mkPrtM5CcOpvsZACRqhJTgVHRqk27vKVJbwmiwUSIHnnbVGTDjnYaJ43dFIfnKhJlgBmMBArpUBwBmYdaicDu9DnSUDBra_69H_AHrXnj8vRyQAWol9z1y-SyuhWb_RbJgEGL0Vzt_sY2hd_Jv_feoG6DdqlYiE5oHsbAEgjNsdOvKTCVJ3Kk5Nf1eqLxRRk6?width=768&height=1024&cropmode=none)
It took a silly amount of time to figure out the studs - but hey ho, they are now coming out how I want them. I haven't documented the process because for most people it's rudimentary stuff that we've all done. I think.
Anyway, I also made a packing nut, from a piece of hex bar.
(https://dsm01pap002files.storage.live.com/y4mQAVmB6zqxoX2PaE7q8HOtaFkRwh-dumViOWyxY2rnQgHXwmyJk3ZltWfqiB2fSR96lwne3G-Fzx_44_LX4swB9Mr7F5KfFjLUH3jfzLwgfpWIn2wBFUMdghycFMWdnkch1Vr-nIP127u5wd8QcnoNF_3rtbr2tIY2Jwb6rSpsT16QfuJxH3potIq_gwUA3WA?width=1024&height=768&cropmode=none)
I am a big fan of the upside down threading tool approach, running the lathe in reverse and threading away from the headstock. It is very stress free.
Touching off on a sharpie mark to establish the OD:
(https://dsm01pap002files.storage.live.com/y4mIOIgH6kOytchPCLgAhe8kFIrwfJL1zcUdJKKFxe27Lp2eobO55GVUp78aIx-1XiSk6yomoJoYXFJTGM8MhdfLncK7T8UebGl9UjXu_LVxLobHSDDKWZcjJjhA-UeQGEE2x8H8YhTA62UQ2-wFFsZtAE8zCEsPjFZup0tLRCpfUz-BlFh5S4oKD4nrHVnMLci?width=1024&height=768&cropmode=none)
This is a 1/2-20 thread. I tend to cheat on my single point threads and just use a nut to check how they are coming along. Since I'm not selling these parts I'm OK with that, but today, since I have a set of thread wires, I just felt like trying them - and actually they are easy to use. These ones have a little rubber device which holds the pair of wires for one side, and attaches them to the micrometer anvil, making taking the measurement a very simple job.
(https://dsm01pap002files.storage.live.com/y4mOn1G6yuzK9W0eI9a_gq4qIjIGRN-Vzt0jWFMdmDX8cxM-3JhHTob0C2vow7RZZwjDpS77M4dHrQQHktNlOZ-77Axhvn9QbHnaIkiuW9jJIUf_cudCZDAY-p4q6iiUY6-Vm4J_237nFhxvGfmJ8Iioc56Y-yggSWnurPHE0JRZwjwI6zCRU-cfgon078hKpCP?width=1024&height=768&cropmode=none)
The maths is actually pretty straightforward. I'm not going to go into that because there are many many many sources on the net and youtube that explain it, but there is a handy dandy chart that comes with the wires to make it easy.
(https://dsm01pap002files.storage.live.com/y4mzVQIR5C-rHqTIpRgM_JO96Rg5MfdDtHx-gsEAkGdcLUxVUf_6gJ2b6CSKeuIdY-xTmabbRMdTHuRtPXFZdyrBRqkiWtUjz1jEBDjrkgdyISs_H14ei7j92fdYhA1OiGKbC8E1o0K56ctl2SMMpMDd1JrgQASTV0RJfn9FkDCRYw43PWkWD6lWhxBPym-it92?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m6uX-TOUOBqzdQ3DEPEAwogy1OdujIXlzKO6C_V4I4DXuT7SjWPA7wqcIcuF-PkqwhvGqjN4ia9sBY_IMCy_h8L8OeGJXiCLljiZmwQ-8uN-naR4p9q09Szx7teOVBVkdWDq2ktH3YzJKLfWGASjbs2R0sbV4LSyDeL9np1cHCZrHK8FUUTc8ua5ke1aBdWO3?width=1024&height=768&cropmode=none)
A simple part really, very therapeutic. It even fits the mating part.
(https://dsm01pap002files.storage.live.com/y4mifGJxHYopSOJ2tEhuQN3ZWxkGaq4titzHhmPCI_j77svq4swJMKYlUVPgD1VGY_Kh5YgNaO8YTcGEtGyabHQxG0pgMdVxAP1wfFEmP4i5nl99G7TldbtfBGQRScwuFbuNREMgbpI2apNw9gNAY-mo6Nhv-Z2zrOStFY0079WLLALwXh7L0_-yHcH77VNmWkS?width=1024&height=768&cropmode=none)
Anyway, that's a few things I have been doing. As usual, when I write about it I wonder what took so long. Nearly finished on the bearing studs, then I just need to make some custom nuts and I can machine the crank shaft bearings. Something a bit more interesting - after that I will be onto the crankshaft I think.
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Nice progress Stuart and the parts looks good too :ThumbsUp: :cheers:
Per
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Nice job with the thread & brass fitting Stuart.
You are spot on, single point thread cutting is very rewarding,
I have heard of the reverse threading method, but never tried it,
well I have only cut a couple of threads on the lathe anyhow :)
Have you got a foot break on your lathe?
And, in your case did you spin the lathe in a forward direction to return to start? or simply using the thread dial?
Gary
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Thank you both!
Gary, I do not have a footbrake on this lathe. That would be a nice feature but it's a fairly basic machine. This was a 1/2-20 thread, and I have an 8 TPI leadscrew so I can use the threading dial, and just return the carriage by hand. I like to put an undercut on the thread so that gives me a space to move the tool in and wait until the dial comes round - this makes for a nice thread. I have also learned to just run the lathe slowly for single point threading. Theoretically given that I'm cutting away from the headstock I can use a higher speed to better suit the diameter and material, but in reality I've learned it's easier for me to engage the half nut in the right spot by taking my time. I do occasionally get ahead of my abilities.
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Nice work Stuart. :ThumbsUp:
:popcorn: :popcorn:
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Although I frequently turn from the headstock out, I’ve never threaded that way.
I’ll have to try that.
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Just make sure that your chuck cannot unscrew - mine is a threaded chuck mount, but it has screw on locks that prevent it unscrewing when turning the chuck in reverse.
I like it as a single point threading method because in general you just run off the part, giving you a lot more time to deal with stopping the machine, plus you are not trying to wind the cross slide out at the same time to stop cutting and so on.
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Yes, had the chuck begin to unscrew many yrs ago on my SB9. Sol long ago that I can’t remember just what I was doing.
I do remember that it got VERY interesting in a hurry.
I suppose I could try reverse threading with my er32 collets, as I hold the collet chuck in the spindle with a drawbar.
I always use the back gears when threading @ about 50 RPM with no problems, so probably won’t’ try it.
I’ve always wondered how folks thread with lathes that have 130 or 150 RPM as the slowest speed.
I guess you adapt, I dunno.
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I find I have to go 50 rpm anyway to make sure I engage the threading dial properly (i.e. at the right spot). That bit is just practice (I hope).
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Prop, I read in another thread that you have a Matchless you were going to restore.
What model is it?
Team Obsolete has a G50, Dave Roper took a victory at IOM on it.
One of my buddy’s in High School had a 650, I think it was a G12.
There is a ‘55 G3 on Craigslist in LA, bone stock. Same owner since 1963.
Sure glad I don’t live closer, as it would look good in my garage.
I’m enjoying your PM#4 build. Thanks.
Cheers
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Hi Ted,
It's a 1960 G12DL. It is all original matching numbers - frame, engine and transmission, but is a total restoration job. It's all in bits at the moment, but I have most stuff for it. What I don't have is readily available - so it's just a matter of doing it, it's just that I've lost interest. I will probably hold on to it for a while though, because I may get enthusiastic about it one day. In 10 years if I haven't done any more to it I may well sell it. Or if someone offers me silly money in the meantime. That can be a great persuader.
Well, I have made some progress on this engine. I made some nuts for mounting the crank bearings. Those were pretty simple and I didn't take pictures of the process. I still have more studs and nuts to make, but yesterday I went to work on the crank bearings.
First step, setting up an angle plate, clocking this in using a new to me test indicator, which I picked up from the local second hand tool place for a very good price.
(https://dsm01pap002files.storage.live.com/y4mwK2cv3sE55Knz_NE5joDOfx0DY_NAQ_up2qStsindN8Sb5KNFdu1zAKNBIgHZjTVSPtCwtcKVJmHdGcsgQvqUb3U7gDeppoC4aXFXP_8v1D6QUIrZUbjJ2GwltJHz2ctABkEdk77Wjt1KK6JlfxvzMXpFm61JWEoqYy7LnJSfod3tdVgh90X33PMR5mgLZL9?width=1024&height=768&cropmode=none)
This was causing me some stress trying to get the thing to clock in within one division, until I realised it's a .00005" resolution dial. So this plate is well square. I got it under .0005", and vertically it's just as good.
(https://dsm01pap002files.storage.live.com/y4mQLNL2LtC8BdFR3cfgXRkpd0mD5XKR4UbPsNNLVtelFf9K1VnKdIYn-ahv0VJdCka5eWIQzH2M-HyN9tphP_fo--EBJb6-EW39dn6JAN12UAVpXzE3LTrkB4s-kr6Y41X26FrDjC8GHt4yrAtSPFXwoit1fk9QUjb_Mwpr-2HeQmMz0L0WwNiuEai2yHe9PlH?width=1024&height=768&cropmode=none)
Quite a nice find that.
Anyway, then I mounted the base and bearings on the angle plate.
Since the bolt pattern was carefully set up and dictates the centerline of the crank shaft I am using tight fitting gauge pins in two bolt holes to get the part level, and also to establish the centerline. Really what I should have done when I drilled that bolt pattern was either drill and ream some reference dowel holes, or machine some reference surfaces on the side of the base, which would probably have been a bit more accurate. However, this will work plenty well and I know better for next time.
(https://dsm01pap002files.storage.live.com/y4mLpwc16Gqnse3FKBcwckSt07oxGBtoKKwQyJkHvgglhuNj-PMwNrNEURuVfkVwpHAJ7fpYsu5eQFnkQa7kSIFY6qjsEroUh6OvennYJrNQ3Hkik_mQEqQObeue2HfJOU-Hefoy0GHmkQoIy6nctef2t_8XA9bElplSUJAxl--LygXcfkEQ7M2xIGpN4ws2Fzx?width=1024&height=768&cropmode=none)
Bearing block back on, and bearing surface located using an edge finder.
(https://dsm01pap002files.storage.live.com/y4mVq-enQipFJppPPPkYUXsUKA9WO6lsKQL6eGUIBLgNbSsRG3McOp1RhWzt5XTFvAG6FvTecZ1amhLNIqUHSPJA5hea63QPAeJgGql-gFDqhPwJGA_ZjRYyU0o2nTXBumVICnO-bL_7PxkuyjYDqO-RNgxVUi2lVeiFCSUp9R81IkB6sntQqe90LNQqHhFBBBQ?width=1024&height=768&cropmode=none)
Then spot faced the bearing to get a flat surface and check visual center on the bearing:
(https://dsm01pap002files.storage.live.com/y4mYEP2gZqbZeFB6x4XfRyvehEATml4DlP52wW0gQsVti8K47ZT_1EuzU3OOl4hfi3gNlDx20jDrsw38YvsucKyRm444vaxMHU1kqh4H0E1TAGmcOep7ZIAhfq7sNBKex360fM8RqvdvUYKMz-y4PKC5Gtkc1hFAWy-lmnr7SeZV4GSihPk6Y1KSsNfaM8OBhgo?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4m6tQ1wApjC9LVDwCqQ7SPmiXQvcukDS2tRrZcNAi4OC7UGQrS373WzpUrBhh9zAVHrj3vVTQtWXn_qg50sMWjC-x4D-Z6krDb7h-maS4cs0WnWX2pXVwRQe2wKABYYLbWrjneIC6a0dQdALLRAKki4bI8ReO-dtt2xhi99jWKSa0tYgWIgtECffAa_fQ24gr7?width=1024&height=768&cropmode=none)
Looks pretty good - still some hand blending of the cast surfaces to do.
Then step drilled the bore up to 1/2" diameter. I am shooting for .625" final dimension. I have a boring bar that will reach across the 5" span to machine both blocks in one go, but it has minimum hole clearance of .575". None of my drills will reach the far bearing in one go.
(https://dsm01pap002files.storage.live.com/y4mxtGZh0N3bK0fKfuRg_1sXU2PbwSmFcFKdRwX1Y73ntWwueGh8L_79C-1J0MpBNswptWyLQ63j_NADRB59LjcO8jK3vBLSThIMpiy8FCed9S_aLmIGFTzijVj0gh1TYOtYSlIFeNx8s1irzTPbdyAmpYXgjEj1aqYe9hH47gbDN5WPuZfBpK9RwLbS828xD5B?width=1024&height=768&cropmode=none)
So, I made an extension tool to allow me to spot face the far bearing and step drill it.
(https://dsm01pap002files.storage.live.com/y4mrM0ChuyrQHIjFLn9D4JNEffBsPo9dFBIewaZHaVQ8u2-QWgCD99Xq6BocG3ln4b1JHWwsVYybz-2y7CmsdRIietX_5UsBJo9h-a8_Tr0QbxxKx9uFGKYLBTDZq8W0_qXHJGyj8HHkX1vHtheAkMICOMBwBFWaSFXPZRbXm8m9WPp190j6esMMqOBBhT38r8s?width=768&height=1024&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mAsHkH_q-m2PWP6qf1eW8p7kGjBatzHC4t__fw2e3gcvxFCFft65xjswSze9YDv4Idenjhv_UkzKVX0t4QrF_TVRtEWB9lQ9qa2RaNRC3FC3fEXCpzPMaT4hm0mp7Bf1Kx8ug-G1XvNJtjymxqA9qa6CJummGY20X1i9KLRaWHny5EeQqgsFTzVzWnbHRZ56T?width=768&height=1024&cropmode=none)
That actually worked pretty well, and then I was able to just about get my 1/2" drill through.
(https://dsm01pap002files.storage.live.com/y4mnUeVOKPX9-HUia32eT-3gs73AOugM7ecSMfgahXOUH64sj-ly3c-M1pzcCFX_Ptpdpvy8meElNC8YAxA57kHBwgccVWBYXrFGlWyIsA_-KX9vL0OolVh6jAu6JAadBlR37ME6O9cwEyHV5rjno5uEPBrAV7NiUVoXsx-K_Q_aJdfNfdg53l2zvsuoGi5OFtO?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mhBgzg77L6-RW1hy3GXPqKkO51vlaBWDRKhRhMkO-QK78_O3QGrYtiXHRDHf6A1rPKz3ggXVqzaJuBc8W5R7z9RSn7lOj1tHvQhJUdU3V6LM6xtKSvHJx5UBOzrK2Tn7ClG3V_FOsZHi8Tu1O8qEt8tRhUbhkfAVrn3Lnd0KAK5scl0x_I44RuRkmhtCaW-XI?width=1024&height=768&cropmode=none)
Final stage was to bore through both bearings and take them to .60".
(https://dsm01pap002files.storage.live.com/y4m6hchOiWE-qPpy2QM6oPJMv3qFOzJkezQ0B2QHQz00esNC_DBwAMzf-ibAYjCjqX1pSN5gbb2C42itKVv3ndwUVWraVvBHpd4wQn5_azn9-5qFy1i6BZS9SLnS36qJFRL7ax9RC33FyYgHMHRBEr2OXyFlH7eqK4NG0L5CzrEwD6FAFOkysL2JTQrz51NHvcX?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mjg2A0EwHFbgvRgCm9ZTakgSODoF4nV2MkVJjTwcawthPnzsZGVH2UcOYH4ZcWj3fkSlkh-zNcAeNdCROum00d6EqxOJjyT9gH9deqBffcG5DWp_cJ0Pj_HLWTViJC71lCoW9my_DI-AGFm3vKNfcT6gboi73YBKd9KjT9zkeXUuL1BN4tjDHoqKhUP8igGq-?width=768&height=1024&cropmode=none)
That's not the final actual boring bar I used, but you get the idea.
Last but by no means least was to ream through both bearings to final size.
(https://dsm01pap002files.storage.live.com/y4mcIBkuSLQP15tRc-KOibdhmHsVxu9LBXYRuyolBzzxWQ7uph6zKiQfSJWW0tzcxGdsRrqzzWXjYJ-03prfWtujdE8nvqzl3eyUAH2sPoPkTBsg7d3p8LxAuqSJ04gk09h2wh1VTqJLU1vpTIhhds2Z6slQthED7Fj7SXJ4zg6WMf6paqPp80kSq6CKlbTw8hg?width=768&height=1024&cropmode=none)
And there we have it.
(https://dsm01pap002files.storage.live.com/y4mYIsH2GxR-8dAwOp6c8cJD-FZkKfZARA2TTDKnfkRR4qKhn4rHk_OqY_dJ_woXP_Pu14ztVABIHbSmulJlopOcScMIe5IN3CXeBk-XvLZ9DhTaBg_8bPprr-ixlBTFll6ZUJw0CDJnrQTEzpIjlazQ77T1d-9xiWg3J_IyznoUkA9bbS6N1nUJ1GbvcgxNTNB?width=1024&height=768&cropmode=none)
Checked with a gauge pin both bearings are a perfect fit. I don't have any .625" drill rod to check alignment, but a crude look with a piece of cold rolled looks good, and the bores are dead center on the split line - the gauge pin sits perfectly in each bearing half when the bearings are split. As far as I can tell everything is straight and level, so I think all the effort in set up was well worth it.
(https://dsm01pap002files.storage.live.com/y4mZtb0cXzYx-mYEnkLVkycp6m9NSLgf6B2FjTKzS9Rl1B69TGQUoF_rgYb8DMOih5gqGYYWD6LX5XL4DRWURo3IlAtxNkOGNiQna73nAF6Fm2GxJVIktlMkWdUGeFoZfg60Utu1qy19pFJNFcvq2L08DiSduvyP6SWtTZsvBeHvPtD0uTz3y-EZzy85hfMNJWj?width=1024&height=768&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mOlXX7Ed-yU6Ga1cnwpk4a--Ph6FkrjBUrxrr0ElQe2tSl8dx4qUsoplwmcETib_lCpPwBFNBpPeNu3wENyAN4jgka-N6t_8d4LUZQjsheAuvGzF6MJT0L5KTqXIaukuPavWOkQNtxb8XyEF60tgUFagvTE6F2LZSTbnWvcK55otH5lt0IHaIjCt4o-FRbKZk?width=768&height=1024&cropmode=none)
(https://dsm01pap002files.storage.live.com/y4mb5fmQ7XyhaDye3uyTR6egEmHMfFpvyCl-ah8PHj34IOp3isDZpxDalOFSQtGuiSCdKpLkTWqHXCOke3Y6nkgT0tGjryRDPwI9yA-ZJCylOPoqHORFTO5_O4jMH7yPZgxSjDBwDGsokCgZVRL__UwgjRDrbODLUm1zJVy8u96CIoz0cLgw58ZpLz69La1CRsk?width=1024&height=768&cropmode=none)
Very happy with that - again using location techniques to do everything by numbers - seems to get accurate results.
Next up - don't know. Possibly start the crank shaft, now that I have the bearings done, so I know what to machine the crankshaft to. Same dimensions as the drawing for once, since I got the bearings right this time. :Doh:
That all worked very nicely, but honestly it would have been easier to just remove the top bearing block to do the bulk material removal on the lower one. The key was to do the final boring through both blocks in one go, up to that point it's just material removal. A good exercise though.
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Great update, Stuart! You got a lot done there and your careful work made it all come together well in the end! :popcorn: :popcorn:
Kim
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:Love:
:cheers:
Don
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Since my major change of location I have been seriously distracted by other things (hill walking, growing potatoes, painting the house, etc... :)) and my workshop still being in storage doesn't help. But it's great to see the work you have done on this engine so far and to see it taking shape. Makes me look forward to getting back to it when I get a shop built, but nothing happens quickly up here...
All the best, Stuart.
Gary
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Thanks Gary.
I've taken to filming my machining, mainly so my Dad back in the UK can watch it. It gives us plenty to talk about on our weekly video chats.
Anyway, should anyone be interested the videos are on my youtube channel "Stuarts Shednanigans" which I thought was a fun name, but probably isn't.
A full playlist is here: https://www.youtube.com/watch?v=vQN-pNlly84
And if you don't want to suffer through that lot, the first test run is here:
https://www.youtube.com/watch?v=nJQ0ww3S6Ig
I'm pleased with it just because everything went together as made, with no adjustments needed - that was a goal I had - to achieve enough precision for the engine to just run without having to be forced to bed in with a power drill or whatever. It runs on a minimum of pressure - 5 psi is as low as the gauge goes, and right now the engine does not have piston rings in, so it leaks a bit of air. I have to believe it will really run well once I get the piston ring situation sorted out. Overall pretty happy with this.
Flywheel runs nice and true as well.
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Nice video and great to se a smile when it starts to run :)
I would say that you have a very sweet runner - so I understand why your are chuffed :cheers:
Per
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Hi Stuart, you have successfully completed the construction of the steam engine. And she's doing great. 👍
Michael :cheers:
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Thanks so much to you both. Today was a very rewarding day, the engine runs as well as I had hoped, so my work paid off. This is a big improvement over my PMR #1, which locked solid on assembly and took a lot of fettling, and then running with a power drill to get it loose enough to run. That was a disappointment at the time but lessons learned have paid off.
Now to make some nice custom studs and nuts for it, and to add the lagging for some visual appeal. I may well lag the cylinder with wood strips.
And let's not forget painting. British racing green this time maybe? Or burgundy - like the glass of wine I intend to celebrate with.
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Great result, Stuart, she's a sweet runner. Congratulations! :wine1:
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Ticking over very well! That smile when it started up in the video says it all! :ThumbsUp:
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Hi Stewart, great to see it running so nicely after all your careful work.
A major milestone and just the finishing touches to go now.
MJM460
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Wow - she's a chunky beast is she not? :ThumbsUp:
Great work, Stuart, and the videos certainly bring the build to life. Congratulations! :cheers:
Hi MJM. Long time no see. Hope all goes well with you.
All the best from a morning of fine, windblown horizontal rain on the Isle of Skye.
gary
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Hello.
Figured I would round out this thread. I finally got everything painted and put back together. So - finished engine:
(https://onedrive.live.com/embed?resid=9B2D555CA7044C4F%2123492&authkey=%21ALSYBJ32NR521Q4&width=660)
(https://onedrive.live.com/embed?resid=9B2D555CA7044C4F%2123485&authkey=%21AP7RcxScZSpy7Tw&height=660)
(https://onedrive.live.com/embed?resid=9B2D555CA7044C4F%2123487&authkey=%21AE9BSWVFSzQ5Idw&height=660)
(https://onedrive.live.com/embed?resid=9B2D555CA7044C4F%2123489&authkey=%21ACwicX-xhfFMRX8&width=660)
Couple of videos in case they are of interest. Make use of the fast forward button to get to the running engine in the second one. First one is just about pinstriping:
https://www.youtube.com/watch?v=_eULUaV9EPc
https://www.youtube.com/watch?v=_oKz71BNHuU
Anyway, there it is. All done. On to something else now.
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She's a beauty, Stuart. Most elegant.
gary
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Nice work, Stewart. Especially that pin striping - really finishes it off nicely.
Looking forward to the next build.
MJM460
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Stuart, the end result is great!
A nice green, meesing around the cylinder, the painting and the self-made nuts.
What is the next project?
Michael
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Thank you all. I am very happy with this engine - runs very nicely and I think the overall look is pretty good. The pin striping is a bit of a cheat, but it helps finish the engine appearance and if I'd attempted to free hand it I would have ruined the look - just that simple, I've never been much good at that kind of freehand detailing.
Next up is to be a Model Engineer Beam Engine - so something a bit more intricate. I have the castings, which I obtained from Reeves. I understand that there are inaccuracies in the drawings so I shall see what I can find out before I start, and then be on the lookout as I go.
Before I can get to that though, I have a new lathe coming (today supposedly), so that will have to get installed and set up first. I have been getting requests from people hereabouts for repair parts for farm equipment - mostly simple stuff - and that seems to be enough work to finance a new machine without sucking up too much spare time. Hoping to get a knee mill at some point as well. Anyway, I started a small business around that and independent mechanical design and drafting services. Figured if it takes off I'll go self employed and ditch the increasingly aggravating day job. That said I think it's highly unlikely that will happen, but if it brings in just enough loot to fund a couple of bigger machine tools that works for me.
Thanks all for your kind words - I really enjoyed this engine build, learned quite a lot along the way as always.
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I wouldn't have tried freehanding that pinstripe either!
Sounds like some great developments are taking place for you with the expansion of your shop's capabilities and output!
:ThumbsUp:
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Beautiful model, Stuart! :popcorn: :ThumbsUp: :popcorn:
There's nothing 'cheating' about using decals for pinstripes, or for lettering, or anything else for that matter.
I mean, you could say someone who paints their pinstripes is cheating because they used purchased paint - they didn't make their own! Most people purchase fasteners, but some people make all their own. Some people purchase castings, some people enjoy casting their own. It's all in what brings you the joy of buildiing that counts.
I'm all for whatever you want to do!
Kim
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Hi Stuart
Long time no see ;) .... but good to see the end result :ThumbsUp:
Great paint job + runner :praise2:
Per :cheers:
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That is a good looking engine and it runs fine as well.
Good luck with the new enterprise.
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Very nice, love the pinstripes.
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Thanks all - very nice of you al to comment. Excellent points Kim - it's all down to personal preference at the end of the day.
I'm planning to build a Reeves ME Beam engine next - hopefully record that along the way. The new lathe arrived safe and sound - I'm just working through the 3 phase converter install. I had an electrician lined up to do the work but he backed out at the last minute. It's not that hard of a job so I'll do it myself - I was just hoping to have it done quickly. With limited time it will take me a little while, but the saved money will be handy for some new tooling, so all good.
Thanks again.