The Home Machinist!

Bill Shields wrote: ↑Sat Jan 29, 2022 6:37 pm Ok...so the crank has not moved on the pin...this eliminates one potential variable.

I already had seen a toy locomotive of 1 metric ton where the pin had rotated in the wheel bore.

Bill Shields wrote: ↑Sat Jan 29, 2022 3:19 pm All suggestions are assumptions that AT ONE TIME THE VG WAS CORRECT.

Not mine.

I could offer a test if you can wait some time for the result:
Send me the valve piston positions in piston dead center position and the valve and piston position when steam inlet closing, each for forward and bakward riding, and I try to tell you what to change on your valve gear.

If you do not have any space at all, you cannot have low degrees of cylinder filling because of the outlet closing early which leads to too much compression work then. That is also a waste of steam.

A little boiler feedwater pump for narrow gauge size, a steam pump prototype with fully self developed valve control, contains only one valve piston and some very easy-to-manufacture details within the main piston:

@RussN Good luck

Could you provide an elliptic valve diagram or an x-y table with piston positions (x) and valve positions (y) for one wheel turn cycle?
Ideally this at two or more cylinder fillings, or one backward and one forward.
Perhaps there is something I (or we) can see in these diagram data.

Perhaps you should use the remaining time for training your communication skills rather than to get a steam locomotive running. You did not even tell us the scale of your loco but expect a decision although you even did not explicitely say that you want to pay for the work. If you are willing to app...

This is a good idea! Let me start with what we need to know before feeling free to help someone! So we need to know whether the person asking - suffers from overconfidence. - expects us to read his mind. - believes that being able to help him is our greatest happiness on earth. - lacks basic rules o...

After all I read here, I would expect a contract with the obligation to execute the work for free before getting the drawing.

But do I really want to find out if I am right?

No

Bill if you are not able or interested please don't ask for dimensions. RussN, he wrote this without Bill having refused anything. So which option would you prefer now? a) Promise manufacturing first, and then having the choice between being guilty for disfunction -and- iterating and teaching until...

I think the steam hobby is a rather temporary occupation in this case...