Vertical steam engine with Stuart cylinder

Coming along nicely, strange about the valve stroke/dimensions 

Given that the passages to the cylinder ends are much smaller than the area of the port opening, does it matter that the ports do not open fully? Once the area of the opening is larger than the area of the passage, it won't send steam to the piston any faster.

Yes Chris, I think it's as you say. 

The cross-section will be sufficient.

Michael

I consulted the book "Handbook of Model Steam Engines" again. It's like the "bible" around here. It's actually a Dutch book. There are two diagrams for valve gear with a slide valve. One shows expansion, where the valve stroke is given as e + a, and the other, for full-pressure operation, only the width a is given as the eccentricity.

Michael

I think the cylinder is now completely finished. The last thing I did was build two drain valves.

Next, the base plate goes on the workbench. A blanking plate made of red brass had to be cut.

Michael

https://youtube.com/shorts/EjZU2_IX84M?si=loY5KkcSyQZSWl-7

That's looking great Michael, job well done. Looking forward to the next stages ......

Quite a bit of work in those little valves  Does the pointed end just go into a regular drilled hole?

The cylinder assembly is looking great! 

Hi Paul, yes, the pointed end presses into a 1.5 mm hole.

I made some notes about this valve a while ago. Basically, I followed my notes.

Michael

The cylinder is beautiful, Michael! 

And it goes in and out very well!

Kim

Quote from: Michael S.Hi Paul, yes, the pointed end presses into a 1.5 mm hole.

I made some notes about this valve a while ago. Basically, I followed my notes.

Michael

Thanks for this, filed away for when the time comes

That's a really fine looking cylinder, Michael! I've never made a valve before so I'm interested in what you've shown so far. I didn't have thread cutting ability on my lathe before, now I don't have an excuse not to try some time. 

Thanks to everyone for the kind words.

I need to redraw the valve. I've modified the valve stem slightly. The diameter is only 2 mm before and after the M3 thread. The stuffing box contains a seal made of twisted Teflon tape.

Michael

I found the plans for the J. P. Duval model steam engine online some time ago and was able to print them out. Now I can't find the website anymore. I think my plans are incomplete.

Can anyone help me?

Michael

I have plans for several of his engines but not this one.

Julius De Waal has redrawn a lot of them so may be of some help

https://www.modelengineeringwebsite.com/Duval_single.html