Another Stuart 10V

[Rudy from Norway]

I wanted to show you my first build, a Stuart 10V. As I mentioned in my introduction to this forum, I wanted to go nuts about accuracy. Pretty ambitious for a newbie or what! Never operated a milling machine in my life. Barely seen a lathe. Bought all new machinery and jumped into it.
Anyway, so far I’m happy with the result. I planned to make a video of the build, but discovered that the video part was consuming so much time and focus that I reverted to pictures and text. Nevertheless, I did this small clip showing the engine at a half ready stage.
Later on I will show some of the building steps I found challenging and some of the mishaps I did.

[ame]https://www.youtube.com/watch?v=s-lJmt8CsDg&t=16s[/ame]

 

[deeferdog]

Looks good Rudy, is the crankshaft built up or machined from one piece?

 

[Rudy from Norway]

The crank is built from separate parts. I made two identical discs that i drilled as one piece. This way I believed the accuracy would be perfect and that I could make the rods as press fit. But not.. I got more run out than I was happy with. Then I had to true it up in the lathe between centers. Not a big deal really except for I had already drilled the flywheel for the first dimension (can't believe I did that). I will fix the flywheel with a sleeve, no problem.
The press fit and pinning is very solid though. And it is very true.

 

[Brian Rupnow]

Nice, Rudy. If you look at my post "back to steam" you will see that I am building a twin engine from Stuarts basic design, but fabricating all of the parts instead of using castings.---brian

 

[bwal74]

Hi Rudy,

Great start on your 10V. I have the box of castings staring at me every day, reminding that I haven't started yet.

Please post your photo's, suggestions, advice etc. I'll definitely read with interest.

Cheers Ben.

 

[Rudy from Norway]

Brian, I have already noticed your write up. Very nice build. You gave me many ideas about making a "Standard" looking like casting (I believe Stuart cal this Standard. Cross head is the supporting "piston" riding inside the Standard. At least this is what Stuart say). The rest of the parts are pretty easy to make from bits and pieces.

 

[Rudy from Norway]

Ben, Since i'm new to this I did some pretty extensive reaserch befor i started. The video series by TinkerJohn onYouTube definitely gave me the final push to get started. Recommend he's series about this Stuart 10V.
What I have experienced so far is the importance of planning the work and relations between parts. I invented my own abbreviations that I note in the plans. Like "R" meaning this part has a relation to another part it's going to fit on to. "CR" meaning Critical Relation to another part. Then I have to make sure to custom fit these parts to each other. And "NC" meaning Not Critical and I can make it just look right without following the measurements in the plan. My plans are full of these small notes helping me to not forget checking forward to the next step in the build.
There are a few very critical steps in this build. Making the Standard is one. Make sure the standard is in the machine all the time when you facing the top and boring it. This way you will have the centerline in the bore exactly 90 degree to the face you mount the cylinder. Next is th make the cylinder the same way. Have it in the machine until the bore and bottom surface is done. The rest of the surfaces on the cylinder is not critical. The third and often overlooked part is what I have named the "Hart Plate". The part between the Standard and Cylinder. This also have to be in the lathe until both surfaces and the center hole is done. This way you ensure that you maintain concentricity between the cylinder and Standard. This is critical to avoid bindings. I have done my engine this way and have no bindings and no play right out of the macines.
The pictures showing the setup for the standard. Note the small wise, it just hangs on the standard to add some weight an stop vibratinons.

 

[Rudy from Norway]

I'm over the moon! My Stuart had its maiden run tonight. And it's running quite well. I swear, I have never run this engine before this video. It's not adjusted, I just put on a hose and blew in it. I did two "blows" before this video, but the camera shut down and I lost the file.

[ame]https://www.youtube.com/watch?v=HLmRA9UI6hA&t=36s[/ame]

The second run was on 30mBAR through a propane gas regulator. That is 0.44 psi. I guess that's acceptable for an engine like this? I don't know what these engines usually need to run.

[ame]https://www.youtube.com/watch?v=U66IOjkmGqw&t=32s[/ame]

The third attempt was with a bit more pressure. Still not much though. Notice the relatively low vibration. I guess the counterweights on the crank shaft are doing their job. I'm very pleased. After all, it's my first. I think I'll pass myself to the next build.

[ame]https://www.youtube.com/watch?v=DyVnKarTcSI[/ame]

 

[Herbiev]

Well done Rudy. Great runner

 

[Charles Lamont]

Congratulations on a really nice job so far.

 

[Rudy from Norway]

I think making my own fittings was a good idea. Nice and easy to make. This one has 6x0.75mm threads. Probably not a good idea if you have a lot of engine and boiler equipment you can mix, but this is my first ever steam fitting, so I can make it my own standard. After all, I will make metric engines in the future.
I also got to test my new little rotating table with scroll chuck. Very nice to work with.

 

[Rudy from Norway]

Another way of making a gland nut. Also with the nice little rotatong table. Easy to make the correct indexing this way.

 

[Rudy from Norway]

The bearings where not easy making right. I had to make them a couple of times. The most used way of making these I have seen uses the top side as reference. In my opinion the underside is the desired reference. Using the top imposes an extra inaccuracy factor. As seen in the picture (4. pic) the center is not pointing at the correct place as scribed in the layout. And this setup is commonly used.
I opted for using the mill. Placing the bearings in the wise and drill both bearings in the same setup will ensure good repeatability. However, I discovered a serious accuracy issue. Note the edges on the wise are pressing the part (reference surface) out from the wise. I scraped out the corners from the bearings so they rested flat to the wise.
The bearings are of cause not touching the bottom of the cutout in the sole plate. Just rests on the top surface.
In the end I reamed the bearings in line when they where mounted on the sole plate. Got them very accurate. I can turn and interchange them without bindings.

 

[Rudy from Norway]

I find it very easy to make hole patterns with the help of an edge finder, DRO and an online bolt circle calculator. All pars will fit either way. I haven’t tried any other way, but I find myself using the DRO all the time.

 

[bwal74]

HI,

Was your little rotary table expensive or a one from India or China?

Ben.

ps Nice work too.

 

[Rudy from Norway]

bwal74, It's this one, from India. $150.00 shipped.

http://www.ebay.com/itm/Tilting-Rot...650979?hash=item2841eb98e3:g:K-oAAOSwAPVZJbNQ

There is one disadvantage with this. There is no natural center reference at the table. When attaching the chuck you have to fiddle a lot to get it centered. One day I maybe will drill a hole and make a centering mandrel. This way I can take the chuck on and off more easily.

 

[JCSteam]

Great work so far, I'm more than impressed and jealous, but for steam engines running on air, you need to make sure that there is regular lubrication of piston/valve gear as the air, it blows it out, undoing your hard work to perfection, (Which it looks like you've achieved). The engine runs veru smooth, but you need to make sure that its lubricated, squirt a little lil on the exhaust port and run the engine backwards for a little if your planning on running it for a while.

On steam the oil emulsyfies into the steam and lubricated the engine piston valve gear and all. Plus the water acts as a lubricant in the absence of oil

 

[Rudy from Norway]

I have made new crankshaft bearings for my engine. I was not happy with the accuracy. The clearance was a bit too large and the engine had a slight knock at high speed. Actually I think these parts where the most difficult to make on the whole engine. Not just to carve them out, but to find a setup that made them accurate. This is actually my third attempt. The goal was to have no play, no binding and no need for running in. To achieve that, the setup proved to be the main concern. In general I think this part is not made very clever. There is just too many operations required that forces you to take the work in and out of the mill and lathe. You simply loose reference. Next time I will make the bearing and strap in two pieces.
Anyway, I made it. After machining I hand reamed the bearings with an adjustable reamer to the desired clearance, dropped them into the soleplate and the crank spins freely. No black oil from the bearings.
There are two important steps that I paid attention to. First I established the underside of the “straps” as reference. After all, this is the surface that refers to the already flat soleplate. Next I ensured that both bearings got the exact same height from center to the reference level. I bored the whole work before I parted it off to make two bearings. Apart from the clearance the rest of the measurements and operations are not all that critical.
What I would have preferred is to have the work in the mill all time when doing reference surface and boring but I did not come up with any way of achieving that.
At one of the pics you can see I’m using a dial indicator to tram the work to the quill. This ensured that the reference surface and bore got as accurate I could possibly achieve (don’t get confused by the bearings in the opposite side of the wise. They are the old ones serving as distance parts so the wise clamped straight).

I also painted the engine and made a couple of oil cups that are made to look like drip oilers. The glass is from a 1/4x1” fuse. Have no drawings. Made free hand. M3 threads in the bearing. 1mm hole for the oil. I could have made a much smaller oil hole because the oil goes down pretty fast. Glued the glass to the cup with epoxy.

[ame]https://www.youtube.com/watch?v=kbWIckq90-c&t=32s[/ame]

 

[idahoan]

Very nice Work Rudy!
Your finished engine is beautiful and your pictures are also superb.


Dave

 

[Herbiev]

Well done Rudy. Love the idea of using fuse glass for the oilers.