Model Engine Maker

Engines => From Kits/Castings => Topic started by: AOG on January 10, 2021, 06:30:39 PM

Title: AOG’s Stuart 10V
Post by: AOG on January 10, 2021, 06:30:39 PM
Hello everyone, it’s been a while (more than a year) since I posted a build. During my time away I strayed into additive manufacturing and and some gunsmithing but now I’m back and ready to build another engine. I will be building the Stuart 10V.

(https://www.stuartmodels.com/graphics/products/cache/s_800_600_2.jpg)

Just as a note, you will see a lot of 3D printed fixtures and fittings during this build. To be honest, what I have planned is way overkill for an engine the size of a 10V but I am using this build to apply what I’ve learned about additive manufacturing to create useable, printable fixtures for machining. Now let’s get started. The first thing I did was clean up the base casting and flatten the bottom by  rubbing it on a sandpaper covered surface plate until it didn’t rock.

(https://uploads.tapatalk-cdn.com/20210110/b69558f122ff7a58ada73a8d6700a8ce.jpg)

Next the top of the base casting was skimmed flat and the holes were drilled.

(https://uploads.tapatalk-cdn.com/20210110/0655428e89d371f68b4d88ead29718dc.jpg)

Next it was over to the tapping tool to tap the holes.

(https://uploads.tapatalk-cdn.com/20210110/1168fd2b0e747e7568b428d46d914283.jpg)

That completed the base so it was on to the sole plate. First I flattened it on the surface plate and then mounted it to my vise tooling plate. Then I skimmed the top flat . Because of the unevenness of the casting I mounted the part with a 1/4 inch bar through the bearing journals. This helped me to pick up a good center point for drilling the various holes.

(https://uploads.tapatalk-cdn.com/20210110/b5c004973628cd0e768d2a95ae266a11.jpg)

Next I added 2 hold downs to the sides before removing the center hold down. Taking a ball endmill I tried to cut the bearing channel. That’s when I hit my first problem. I am always reluctant to crank down on a casting for fear of cracking it. In this case I didn’t tighten it down enough and the part moved while I was trying to mill the slot. I reset and added an eccentric clamp and parallel to the front to stop from moving. Then the cut was completed.

(https://uploads.tapatalk-cdn.com/20210110/1f57f50852ddeb9e1cccaa976941d6f2.jpg)

Even with the screwup I managed to get a good fit on the bearing caps.

(https://uploads.tapatalk-cdn.com/20210110/9450bc405065e5026aa9caa8f32af70a.jpg)

The part was removed from the vise and the holes tapped.

(https://uploads.tapatalk-cdn.com/20210110/19bdf30c1cd6036df3cb42d7d1383a34.jpg)

That completes this first installment. Till next time.

Tony


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Title: Re: AOG’s Stuart 10V
Post by: Dave Otto on January 11, 2021, 01:24:20 AM
Hi Tony
Good to see you back posting a build.

Dave
Title: Re: AOG’s Stuart 10V
Post by: crueby on January 11, 2021, 03:01:31 AM
Nice start on the engine! I've used printed parts a number of times to help keep track of shapes and plan out order of things, not for fixtures yet though, be very interested to see what you come up with.
 :popcorn: :popcorn: :popcorn:
Title: Re: AOG’s Stuart 10V
Post by: Mike Bondarczuk on January 11, 2021, 09:39:37 AM
Hi,

Nice start to the build and I shall be following closely as I have a 10V kit yet to be opened, so will be looking for tips as to order of process and holding fixtures.

Mike
Title: Re: AOG’s Stuart 10V
Post by: Chipswitheverything on January 11, 2021, 02:56:01 PM
Will be interested to see your build ideas.  I recently finished a couple of No 10 verticals, one of which I began as a teenager back in the late '60's ! Made a few bits every now and then, but decided that it was time toactually finish it, still remains to be painted though!
Made a few simple mods to the design to be a little more prototypical, and I found it a very pleasant project to engage with.  Though it is "easy" compared with more major model engineering projects, I thought by the end of doing it, that actually it had required a surprisingly full range of machining techniques to make all the components.  So, quite an interesting little model build.  Dave
Title: Re: AOG’s Stuart 10V
Post by: AOG on January 17, 2021, 11:13:31 PM
Thanks guys, I didn’t have a lot of time this weekend so this one will be short. I spent some time making the bearing caps. First I cleaned up both ends of the extrusion and turned one side of the first cap.

(https://uploads.tapatalk-cdn.com/20210117/9f69449adf3de954d64f394f87b4a60c.jpg)

The extrusion was then drilled to 1/4 inch.

(https://uploads.tapatalk-cdn.com/20210117/782dc1973f72867c5bdee1f945d04341.jpg)

The bore will be taken to final size in situ. Next I split the extrusion on the band saw and turned the other side.

(https://uploads.tapatalk-cdn.com/20210117/61d83a52b7f4b89f0076065167dc68a9.jpg)


The other cap was then turned. Both caps were placed on a fixture and drilled for the mounting studs. I also drilled the center for some PM Research oilers.

(https://uploads.tapatalk-cdn.com/20210117/ecb1d3c7285907574248d3a19b483423.jpg)

The last task for this weekend was to tap the holes for the oilers

(https://uploads.tapatalk-cdn.com/20210117/3386f333f28bf2d927fa20eefe8c29c7.jpg)

Then I hit a snag. The 7BA bolts that I ordered haven’t come in yet.  Since I don’t want to ding up the nice 7BA studs the kit comes with I will hold off on the final reaming of the bearing caps until they come in. I think I will end this with my first family shot.

(https://uploads.tapatalk-cdn.com/20210117/ed0fa4006cd233c46d585d5e47561fd3.jpg)


Before I end this, I do have one question for those of you who have built one of these before. The rounded ends of the bearing caps are asymmetric in length. One side is 1/8 in length and the other side is 5/32. It’s not clear to me what the correct orientation is. Should it be long end facing inside or face out? Thanks for the help.

Tony


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Title: Re: AOG’s Stuart 10V
Post by: propforward on January 17, 2021, 11:17:36 PM
Excellent work as always. I like that multi hole fixture plate - I really must make one of those - looks like a very useful item to have about.
Title: Re: AOG’s Stuart 10V
Post by: AOG on January 18, 2021, 12:15:29 AM
I like that multi hole fixture plate - I really must make one of those - looks like a very useful item to have about.

I’ve been wanting one for years but I couldn’t bring my self to do all of that tedious drilling and tapping. I was looking into designing one and getting it C and Ced when I found out that Saunders machine works already makes one designed to drop into a 6 inch Kurt. It Was only around 70 bucks so I bought one. It’s working well so far.

Tony
Title: Re: AOG’s Stuart 10V
Post by: propforward on January 18, 2021, 01:43:52 AM
Brilliant - hardly worth the time making one for that price. I may have to pick one up!
Title: Re: AOG’s Stuart 10V
Post by: Charles Lamont on January 18, 2021, 08:43:39 AM
Before I end this, I do have one question for those of you who have built one of these before. The rounded ends of the bearing caps are asymmetric in length. One side is 1/8 in length and the other side is 5/32. It’s not clear to me what the correct orientation is. Should it be long end facing inside or face out?

I think you will need the long ends inwards, to control the crankshaft end float, so there should be 5/8" between the faces.
Title: Re: AOG’s Stuart 10V
Post by: AOG on January 25, 2021, 12:12:07 AM
This weekend can be classified as one of those lack of attention to detail hurts shop sessions. I started off by designing and printing some tooling to turn the standard. (https://uploads.tapatalk-cdn.com/20210124/c7b01081c46f62ee671e5af7df5ea7b2.jpg)

I made a couple of different versions to see what or anything would work. Up until now I have been using printed parts only in compression. From past experience, I know that they are weak in tension in particular along the layer lines. I wanted to see if I could print a part that was up to the forces of lathe work by working with the layout direction. I made several different tools with different mounting methods to see if I could make it work. Then I cleaned up and flattened the top of the standard on a surface plate.

(https://uploads.tapatalk-cdn.com/20210124/4119ca1cae300cd7a83c4d96cab40ca3.jpg)


Here is one of the final tool designs.

(https://uploads.tapatalk-cdn.com/20210125/acec3698ac1242250dedd972c7707e94.jpg)

Unfortunately the PLA just wasn’t up to the task. None of my tool designs worked (at least not in PLA).

(https://uploads.tapatalk-cdn.com/20210125/4df56ed63533c5e1750fd33f3961a3cd.jpg)

For each of the designs the support material snapped and the part spun. At that point I put the part on a mandrill and turned the feet in the traditional way.

(https://uploads.tapatalk-cdn.com/20210125/bb070dfcdec9e81336bd0c2e52825755.jpg)

I took the part over to the mill to clean up the top of the standard and bring it to final height. That’s when disaster struck. I forgot to tighten down the hold downs and this is the result.

(https://uploads.tapatalk-cdn.com/20210125/a9a196d9440eb88265393dc2aa6d863d.jpg)

I took a big chunk out of the top. Unfortunately there is no saving this part so I am going to order another one.

Till next time

Tony


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Title: Re: AOG’s Stuart 10V
Post by: samc88 on January 28, 2021, 06:24:16 PM
Hi Tony, before spending on another one you could always try a jbweld repair on the casting. I've seen people have good results with it in the past


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Title: Re: AOG’s Stuart 10V
Post by: AOG on January 28, 2021, 06:41:49 PM
Hi Tony, before spending on another one you could always try a jbweld repair on the casting. I've seen people have good results with it in the past


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I thought about it but the gouge is in an area that will eventually be drilled for a mounting stud. I was concerned with the drill wandering at the interface between the materials. In any case the replacement casting is relatively cheap and I’m in no rush.

Tony
Title: Re: AOG’s Stuart 10V
Post by: Twizseven on January 28, 2021, 08:21:17 PM
Tony,

Sorry to see your printed parts were not up to the task and you ended up with damaged parts.

Colin
Title: Re: AOG’s Stuart 10V
Post by: AOG on January 28, 2021, 09:59:13 PM
Tony,

Sorry to see your printed parts were not up to the task and you ended up with damaged parts.

Colin

To be fair, it wasn’t the printed parts that caused the damage it was me not properly tightening the hold downs.

Tony
Title: Re: AOG’s Stuart 10V
Post by: AOG on February 07, 2021, 10:43:23 PM
I got some time to work on this engine this weekend. My 7 BA screws arrived so I set up and drilled the main bearings.

(https://uploads.tapatalk-cdn.com/20210207/56392fe4d7eaeb322a73730a0dd494aa.jpg)

Then they were reamed to size.

(https://uploads.tapatalk-cdn.com/20210207/64941d898907bc2db341608e2968710c.jpg)

Then a quick fit check using the stock that will become the crankshaft.

(https://uploads.tapatalk-cdn.com/20210207/664cd7c17db5971a10d7ec95d8356ad9.jpg)

On Saturday afternoon my new standard arrived. I spent some time cleaning it up with files and my belt sander. then I trued up the feet.

(https://uploads.tapatalk-cdn.com/20210207/9d4540f58526d0560d81298bfd08a471.jpg)

Since I don’t have a faceplate for my lathe I moved the standard over to the mill and brought it to height.

(https://uploads.tapatalk-cdn.com/20210207/e9ec1755dd2882b9bd8bb5d8e4e34021.jpg)

It’s hard to see in the picture but the outer edges are quite hard. Next I set up the boring head to bore the center hole. My bench mill isn’t the most rigid thing in the world so lots and lots of light cuts were the name of the game.

(https://uploads.tapatalk-cdn.com/20210207/3aca8b7a7aed5b5394a16886ffcfc98d.jpg)

I stoped 5 thousandths undersized to allow for reaming. (Pin gauges are your friends)

(https://uploads.tapatalk-cdn.com/20210207/06d0be2789de01c9a84c4695286cdb6d.jpg)

Since I had the boring head set up I reconfigured and brought the outside to dimension.

(https://uploads.tapatalk-cdn.com/20210207/31d222f5d8dabf895f1e069b0825680a.jpg)

This has been one of those shop sessions where you spend a lot of time but you don’t see much visible progress. In any case, that’s it for this update.

Till next time

Tony


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Title: Re: AOG’s Stuart 10V
Post by: Twizseven on February 07, 2021, 11:58:25 PM
Know that feeling. After today’s efforts on the cylinder studs on mine 10v resurrection.

Colin
Title: Re: AOG’s Stuart 10V
Post by: AOG on February 14, 2021, 11:50:19 PM
It was a fairly productive weekend. The first thing I did was to ream the standard to final dimension.

(https://uploads.tapatalk-cdn.com/20210214/175836d5aaa4340eba1612d3a0924278.jpg)

I was going to do the bolt circle int that setup but I realized the standard was clocked slightly clockwise. Rather than measuring and adjusting,I rebuilt the setup with some pins to clock the part the way I wanted and drilled the holes.

(https://uploads.tapatalk-cdn.com/20210214/5b32d12f2111079716f5e7a4d5c4ff73.jpg)

The standard was flipped over and the mounting feet drilled.

(https://uploads.tapatalk-cdn.com/20210214/9c2822fe3047ff43bdebcc030484a808.jpg)

That completes the standard so I started the crankshaft. The crank webs were cut to size, glued together and milled to shape.

(https://uploads.tapatalk-cdn.com/20210214/c3ee13743d576224ae62027f0d0468de.jpg)

Naturally when I went to drill the holes the glue bond broke. I rigged up some stops and drilled he crank webs individually.

(https://uploads.tapatalk-cdn.com/20210214/470819d34793aa64b4c64e9df8f73420.jpg)

Next shoulders were turned on the crank pin. I also center drilled the end of the crankshaft for decorative purposes. Then the crankshaft was assembled on a surface plate.

(https://uploads.tapatalk-cdn.com/20210214/deaed23086b27a28b7928aa57ac6a9fd.jpg)


After the loctite cured I drilled the assembly for pinning.

(https://uploads.tapatalk-cdn.com/20210214/73940c1dc8acb8cac34f31adf025f811.jpg)

I used some 1/16 inch drill rod as pins to pin the crankshaft.

(https://uploads.tapatalk-cdn.com/20210214/5e1000c9646203c139ad936ee4b8e5a7.jpg)

That’s all I can do until the loctite cures so I’m calling it a session.

Till next time

Tony


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Title: Re: AOG’s Stuart 10V
Post by: AOG on February 21, 2021, 09:37:06 PM
This weekend I finished the crankshaft. The pins were cut short and filed flush. Then the shaft was cut in between the webs and the ends filed flush. That left me with one completed crankshaft.

(https://uploads.tapatalk-cdn.com/20210221/58d558fd08d453b0b1d85d12c7327ebb.jpg)

Next I started the cylinder. The flash was filed off. Then the ends and valve face were flattened on the belt sander. Then I faced one end in the four jaw to make it flat. The part was flipped and the end taken down to within 10 thousandths of final dimension for that side.

(https://uploads.tapatalk-cdn.com/20210221/367ec71b49698ffa2cd5de3fa81f7f6c.jpg)

Then the center was bored out and the last 10 thousandths were taken off the end with the boring bar to ensure squareness. I ended up with some bell mouthing on the ends of the bore so I came out a few thousandths oversized when I cleaned it up.

(https://uploads.tapatalk-cdn.com/20210221/eaa42029294b325f1b801b255e4af14a.jpg)


Then the part was flipped and placed on a mandrel. The end was turned down to final dimension.

(https://uploads.tapatalk-cdn.com/20210221/b815e33b98e6f6114552ba546667637c.jpg)

While the part was still on the mandrel I transferred it to a collet block and milled the port face to dimension.

(https://uploads.tapatalk-cdn.com/20210221/fe29a0712fbb1732f653ce3024402d01.jpg)


I then set up to mill the first end port when I botched the tool offset. Thankfully I didn’t go to deep but I took that as a sign to call it a day. I mixed up some JB weld and took the opportunity to do a test fit of what I’ve made so far. I’ll end this with a family shot of the test fit.

(https://uploads.tapatalk-cdn.com/20210221/469526b36e1c80d8a9c443dd76e3083b.jpg)

till next time.

Tony


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Title: Re: AOG’s Stuart 10V
Post by: Don1966 on February 21, 2021, 09:42:59 PM
Looking good Tony nice results...... :Love:



 :cheers:
Don
Title: Re: AOG’s Stuart 10V
Post by: AOG on March 25, 2021, 08:20:53 PM
Well I’m back after a small break for carpal tunnel surgery. I’m cleared back into the shop but I’m still not back to 100% yet so I’m moving very slowly. Let’s get caught up from my last update. After the JB weld set I placed the cylinder back on the mandrel and faced off the excess JB weld.

(https://uploads.tapatalk-cdn.com/20210325/75bedae044140dc27f05dca823f7642a.jpg)

Next the part was placed on the mill and the port recess milled.

(https://uploads.tapatalk-cdn.com/20210325/89092130742cf26f7bbfa37a90224454.jpg)

While I was centered up I drilled the mounting holes for the cover.

(https://uploads.tapatalk-cdn.com/20210325/2b48d61938b738c7ae03e5ed429b2e4d.jpg)

The part was flipped and both operations repeated on the other side. Then came the operation I dread the most. Drilling the passages to the ports. (I have destroyed more cylinders doing this task than I would care to think about). Using angle blocks I set the cylinder to a 25 degree angle and made the initial cut with an end mill. This helps keep things from wandering. Then I finished with a twist drill.

(https://uploads.tapatalk-cdn.com/20210325/e82f3189591bef95028448c47e77997c.jpg)

Both sides went well enough so I will take it. Since I am still moving very slowly I will wait until I have enough material before I post again.

Till next time.

Tony


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