My version of Potty Mill engine

[David George 1Participant @davidgeorge1]

Just finnished the valve section and eccentric and done a first assembly. I have changed a few bits to my liking to give it a bit more strength.

David

[David George 1Participant @davidgeorge1]

[Jim NicParticipant @jimnic]

Looking good David.

What's in the box on top of the valve chest?

Jim

[Neil WyattModerator @neilwyatt]

Nice job, David.

Next decision – to paint or not to paint?

Neil

[Harry WilkesParticipant @harrywilkes58467]

Nice

[Nigel Graham 2Participant @nigelgraham2]

That's an elegant machine!

[David George 1Participant @davidgeorge1]

Hi Jim the box is an exhaust with the outlet on the end. I have drilled the exhaust outlets on the top and cross drilled to end.

Not tried it out yet and have some finishing to do on edges and corners as well as lube bits and pieces then clean up the flywheel casting. I probably will paint it red.

David

[Jim NicParticipant @jimnic]

Thanks for that David. One of the things I like about Stew Hart's designs is that they can be personalised fairly easily. I did a similar thing on my version but had the inlet on top and the exhaust on the side.

I like your connecting rod too, I must bear that in mind

Jim

[SillyOldDufferModerator @sillyoldduffer]

David's PottyMill is better finished than both of mine!

Admittedly both were made for the learning experience, but I paid more attention to finish on the second. Perhaps I should make a third, or several…

Curiously my rather rough number 1 runs noticeably better than engine number 2. I suspect it's because №2 is a tighter fit all round, and needs running in! I'm still slightly miffed the extra-effort version wasn't as good as the trainee bodge!

Dave

[HopperParticipant @hopper]

Posted by SillyOldDuffer on 12/04/2021 10:48:20:…

…Curiously my rather rough number 1 runs noticeably better than engine number 2. I suspect it's because №2 is a tighter fit all round, and needs running in! I'm still slightly miffed the extra-effort version wasn't as good as the trainee bodge!

Dave

As Mr Harley said to Mr Davidson, a little extra clearance never got in the way.

I have the same problem: using toolmaker's clearances and tolerances and ending up with things too damn tight for real world conditions..

[HopperParticipant @hopper]

Posted by David George 1 on 11/04/2021 20:13:29:

Love the high-performance con-rod. You'll be able to flog the daylights out of the engine with no fear of that letting go!

[David George 1Participant @davidgeorge1]

It lives. I had the first run on my engine.

I had it connected to tyre inflator, only 5 PSI and it runs great.

David

[SteviegtrParticipant @steviegtr]

Brilliant David. Nice job.

Steve.

[JasonBModerator @jasonb]

That turned out well.

[geoff walker 1Participant @geoffwalker1]

Well done David top quality stuff.

Are you going to set it up with that boiler of yours?

Go on let's see it running on steam.

[mechman48Participant @mechman48]

Super job David; any advice on how you prepped the aluminium pror to painting… was the paint rattle can or mini spray gun ?

George.

[David George 1Participant @davidgeorge1]

Hi George. I used rattle can paint. First an etch primer then a primer followed by finnish coat with fine wet and dry between coats.

David

[David George 1Participant @davidgeorge1]

Got my pottymill on steam today. I had a try with the boiler on the wobbler and lamp but the solid fuel wasn't sufficient to power the pottymill. I ordered a gas burner from Forests and it came today and it ran perfect.

https://youtu.be/VhrElKNqgyY

 

David

Edited By JasonB on 09/05/2021 06:56:26

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