Stuart 10v

[Joe McKeanParticipant @joemckean81940]

Hi, I have nearly finished machining the cylinder of a Stuart 10v and need help with a couple of points

1) What size of hole do I need to drill through the side of the valve chest for the intake and what size and kind of fitting should I use to fit into it.

2) What size of hole should I drill through into the cylinder for the exhaust and what size and kind of fitting should I use to fit into it.

3) And also what diameter should the holes be for the drain cocks.

Hope this makes sense to somebody out there. This is my first attempt at machining a model steam engine and thought I would start on what looks like the most difficult piece and as I haven't finished it yet I have no photos to post at the moment, hopefully as I progress some will follow.

Joe

[Joe McKeanParticipant @joemckean81940]

[JasonBModerator @jasonb]

Stuart suggest 1/4" x 32 tpi ME series threads for both those holes which the tapping drill is 5.3 to 5.4mm.

really depends on how you are going to run the engine as to what you screw into them, If plumbing up with copper pipe to run on steam then the 1/4" x 32 will accept Stuarts fittings, or you may want to go for a finer 1/4" x 40tpi which will take some other makes of fitting. If just running on air then you can make your own barbed fitting to take a bit of plastic hose and that could have whatever thread you have available with the castings tapped to suit.

Stuarts smallest drain cocks are threaded 5/32" x 40tpi ME which needs a 3.3mm drill.

[Brian HParticipant @brianh50089]

Hello Joe, I'll measure mine tomorrow and let you know what size inlet and exhaust are on mine but as to fittings, I just used pieces of copper or phosphur bronze tubes screws into the valve chest; more details tomorrow.

I assume you will be buying in the drain cocks and on mine I used Stuart fittings but I'll check and let you know.

Brian

(Jason beat me to it!!)

Edited By Brian H on 16/10/2019 20:11:24

[Neil WyattModerator @neilwyatt]

If it's the holes through rather than the holes for the threads, they are not critical on the 10V. You could make them to match the bore of the fitting, but anything up to tapping size of the thread will be fine.

Neil

[mechman48Participant @mechman48]

On my 10v I used the recommended sizes on the drawing; I only use air to run my models so I made brass fittings to both ports plus the addition of a mini silencer on the exhaust port, a machined brass tube stuffed with fine wire wool, quietens the exhausts down nicely.

George.

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