Author Topic: PM Research Engine Number 1  (Read 29629 times)

Offline derekwarner

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Re: PM Research Engine Number 1
« Reply #285 on: July 28, 2021, 04:01:45 AM »
Not only very nice, but absolutely a functional need in the build.....I see 5 x stationary cups  & 1 x semi-rotational cup

I needed to check,  however we see  #60 = 0.04 mm or .016"

Many builders of 5" gauge engines in our Group use Steam oil for general lubrication, especially in hot areas.......do you have any intended preference?

Derek....
« Last Edit: July 28, 2021, 04:06:20 AM by derekwarner »
Derek L Warner - Honorary Secretary [Retired]
Illawarra Live Steamers Co-op - Australia
www.ils.org.au

Offline propforward

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Re: PM Research Engine Number 1
« Reply #286 on: July 28, 2021, 11:53:24 AM »
Hello Derek! Thank you for looking in. A number 60 drill is actually 0.04”. Based on advice of someone who built this engine, I actually went to a smaller size to reduce the oil feed rate. I ended up using a .02” drill.

For oil in use I was also thinking steam oil, which seems like it should feed reasonably well. I can’t wait to find out actually.
Stuart

Forging ahead regardless.

Offline derekwarner

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Re: PM Research Engine Number 1
« Reply #287 on: July 29, 2021, 02:27:41 AM »
Apologies Stuart  :Doh:........

I simply copied & pasted a listing ....[without thinking] & saw 0.016" [sixteen thousands] and thought this would be OK for light lubrication oil, however obviously quite a bit of trial & checking will be required, to see how fast the oil is consumed  via the 0.02" oriface :toilet_claw:

My greatest fear  :old:  is always that insufficient oil is available to the journal surfaces 

So following on.......Derek


« Last Edit: July 29, 2021, 02:30:50 AM by derekwarner »
Derek L Warner - Honorary Secretary [Retired]
Illawarra Live Steamers Co-op - Australia
www.ils.org.au

Offline propforward

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Re: PM Research Engine Number 1
« Reply #288 on: July 31, 2021, 11:34:00 PM »
Good point Derek. I'll be watching carefully during testing to make sure oil does actually feed properly.

In the meantime though, todays shednanigans - time for the flywheel. I spent a good half hour first filing off some of the sharp parting lines on the spokes and rim ID, and just generally smoothing it out and cleaning it up. My chosen approach for machining sequence  was to mount it on a faceplate, but stood off from the faceplate on some aluminum spacers - 3 of them - around the rim. I set that all up on the bench, and measured the clearance between the backside of the hub and the faceplate, and machined an aluminum support block to fit snugly in there, so as to not spring the hub when making the bore. As you can see, the spokes are quite spindly.

During set up I also measured the flywheel and the gap behind the rim in multiple places, to make sure the casting was sitting fairly parallel to the faceplate. Although there is plenty of stock I don't want it mounted at an angle, resulting in a thin rim in places or something weird. Then I transferred the set up to the lathe, where I tried to center the ID of the rim and the OD of the hub by eye, using a pointer.





The idea is to try and keep cast features concentric so that things don't look completely out of whack when operating. In the end, it turns out that the opposite sides of the casting were mis matched, and there was a flat spot on the rim, so I could only do so much to keep the as cast features running true - but I at least balanced it as best as I could.

Then I took my time to make sure that I could actually get tools in where they needed to go.



I wasn't planning to turn the OD of the hub - but made sure I had the option available.



Setting up to make sure I could run the tool completely off the rim:



It all worked like a charm, and went without drama. I ran the lathe in back gear at 50 rpm, so as not to risk my set up, but it was completely solid. No singing, ringing or squealing from the part during machining - it went very well indeed.

I did find a couple of casting voids in the rim. I elected not to remove them all the way.



The bore was made by drilling with 4 different sizes of drill to remove most of the material. Then I changed over to a boring tool to take out about 25 thou. My thinking here is that this gives a better chance of making the hole concentric and parallel to the axis of the rim - a drill might have wandered a bit. When there was only 0.008" left to go, I changed over to a chucking reamer to finish the hole.



Checking the bore along the way with gauge pins. Exceptionally versatile tools - I am so glad I purchased a set.



Final check after reaming - a 375 minus pin slips in, a 376 does not. Perfect!



I did not take pictures of the second side - but all that happened there was in essence the same as the first side, the only difference being that I clamped the machined surface of the rim directly to the face plate, and then trued the part up by clocking on the machined outer diameter of the rim.

Once that was complete I transferred to the mill for the locking screw feature - which is a tapped hole through the hub at 15°. For that I set up and angle plate at 15°, which was established using an angle slip gauge to the milling table.

Here I have the flywheel clamped to the angle plate at the hub. Set up is not yet complete, but I ran out of energy somewhat, and besides it's time to get supper going.



So tomorrow I hope to finish clamping the flywheel, then get the upright spoke as close to upright as possible. Then I'll find the center of the wheel, mill a flat in the hub, and drill and tap the screw hole. And that will be that.

Stuart

Forging ahead regardless.

Offline crueby

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Re: PM Research Engine Number 1
« Reply #289 on: August 01, 2021, 01:30:53 AM »
Nicely done, cast flywheels can be a nerve wracking thing to turn, great setup!

Offline propforward

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Re: PM Research Engine Number 1
« Reply #290 on: August 01, 2021, 10:03:10 PM »
Thanks Chris. The more I think about these set ups before actually doing them, the better they turn out. This one was drama free and I'm very pleased with the result.

Well, bit of an update. I drilled the locking screw hole in the flywheel. Spot faced first, then center drilled, then the tap drill. I have this nice ER11 collet holder which lets me get in to tight spaces such as this, and makes the drilling and tapping a breeze. Much better concentricity than a pin vise style holder.





Couldn't use a tap holder, so I just used the ER11 set up to hold the tap. Disengaged the gears and turned it by hand.



I then spent some time doing some assembly. This is what I have so far.









I got this far, and was having trouble getting the steam chest cover screws in, and also the screws for the valve rod gland. Not too surprising, since I hadn't tapped them yet.  :embarassed:

Still, I was able to manually turn everything over, and there are a couple of areas that would benefit from some tweaking, so I will strip it all down and address those items, and maybe next weekend I'll be able to give it its first test on air.  :ThumbsUp:
Stuart

Forging ahead regardless.

Offline Admiral_dk

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Re: PM Research Engine Number 1
« Reply #291 on: August 01, 2021, 10:08:51 PM »
Looks like you're very close to a runner - nice result so far  :ThumbsUp:

Offline propforward

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Re: PM Research Engine Number 1
« Reply #292 on: August 01, 2021, 10:53:21 PM »
Thank you! Yes, I certainly hope so. Very excited to do the last it of fettling and finishing and give it a try.
Stuart

Forging ahead regardless.

Offline gary.a.ayres

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Re: PM Research Engine Number 1
« Reply #293 on: August 01, 2021, 11:15:00 PM »
Lovely work, Stuart, and excellent progress.

The engine is shaping up to be a beauty!

 :ThumbsUp:

gary

Offline Dave Otto

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Re: PM Research Engine Number 1
« Reply #294 on: August 01, 2021, 11:31:47 PM »
Your engine is looking very nice Stuart!

Dave

Offline propforward

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Re: PM Research Engine Number 1
« Reply #295 on: August 07, 2021, 06:24:55 PM »
Thank you all, I appreciate the positive comments.

I tapped the remaining holes, and reassembled today. After spending a little time setting up the timing carefully, I attached a compressed air line and the engine took off immediately without me having to touch it! You can imagine that I was quite delighted at that. Here is a little video I shot to show it running. I am pleased. It is far from perfect, but it runs quite well. It is worth going the extra distance to now strip it and paint it, and make a base of some sort for it, but otherwise I consider it complete and shall move on to another project.

It runs well at about 12 psi. 10 psi is getting on the edge, and below that it stalls.

« Last Edit: August 07, 2021, 06:52:00 PM by propforward »
Stuart

Forging ahead regardless.

Offline Chipmaster

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Re: PM Research Engine Number 1
« Reply #296 on: August 07, 2021, 07:06:03 PM »
Excellent  :ThumbsUp: :ThumbsUp:

Andy

Offline crueby

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Re: PM Research Engine Number 1
« Reply #297 on: August 07, 2021, 08:12:36 PM »
Thats terrific - always a very pleasant feeling when it takes off the first time!   :ThumbsUp: :ThumbsUp:

Offline RReid

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Re: PM Research Engine Number 1
« Reply #298 on: August 07, 2021, 08:17:12 PM »
Well done, Stuart. Congratulations! :cheers:
Regards,
Ron

Offline Admiral_dk

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Re: PM Research Engine Number 1
« Reply #299 on: August 07, 2021, 08:53:51 PM »
Congratulations - time for a happy dance  :cheers: