Stuart Progress

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Your CAD skills are impressive Sarah. It’s very kind of you to make the drawings available when they’re tweaked. I’m sure they’ll help keeping Mr Cockup away!
 
Your CAD skills are impressive Sarah. It’s very kind of you to make the drawings available when they’re tweaked. I’m sure they’ll help keeping Mr Cockup away!
Even with the drawings he still makes an appearance every now and then 😉
 
With the cylinder finished I moved on to the piston, piston rod and the pivot pin. On the piston I made room for an o-ring, I have no idea about sizing the o-ring on on the piston, so it will be trial and error when it's ready to run. The main shaft will be awkward to lubricate, so I added an oil cup on top of the frame.
 

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If you are just running it for display there is little need for a piston ring if the fit is right, infact if you like an engine to tick over slowly then the reduced friction helps

If you know the BS number of the ring you have I'll let you know a suitable groove size for models which compresses the ring less than if it were under high pressure.
 
If you are just running it for display there is little need for a piston ring if the fit is right, infact if you like an engine to tick over slowly then the reduced friction helps

If you know the BS number of the ring you have I'll let you know a suitable groove size for models which compresses the ring less than if it were under high pressure.
Hi Jason, the o-ring I was thinking of is BS1806 012, CS: 0.070, ID: 0.364, OD: 0.504

Thanks again 😁
 
0.090" wide x 0.065" deep should do the job.
 
The cylinder covers have been completed, along with all the shafts as well. When it was assembled it seemed quite tight when the piston was at the bottom cover. I friend suggested polishing the cylinder bore with some 2000 grit paper fixed to a piece of dowel. It worked very well, not only removing the taper, but making everything run smoothly as well. The cladding was added and I used my Photo Etch bending tool to get good folds in the aluminium sheet.

After assembly, I still need to make the gaskets and add the carbon cord, I tried the engine on compressed air and surprisingly ran quite well 😁

Now to degreaser and paint 😊
 

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The painting has been completed and all the parts assembled with gaskets. I ran it on air again and it runs very well, even at slow speeds. Picture of my Progress are below.
 

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The paintig has been completed and all the parts assembled with gaskets. I ran it on air again and it runs very well, even at slow speeds. Picture of my Progress are below.
She looks great! Lovely job!
 

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