Jasonb

I had a bit of a play with the measurements and this is what I have come up with, comments welcome. For the slide valve I have plotted...

Almost looks like they took the design of the valve gear from another engine that had the valve on the ends and failed to allow for them...

In these scales it is such a small difference you would not even notice it under power. Take these two screen shots of the ports that I...

On a model like that just round holes would do or you can mill radial slots which as you say are a lot simpler.

On the slide valve dimensions did you make allowance for the thickness of the disc on the end of the rod? as the ports seem smaller than...

So it looks like there are four rings of holes in the round steam chest and a slot top and bottom. My thought are that the central two...

There has been one on UK ebay for a few weeks https://www.ebay.co.uk/itm/276814498473

On the first photo which looks to be a drip feed I wonder if it is an updraught carb and where it joins the bracket is hollow so the air...

As Said silver steel is drill rod a carbon steel that is accurate on size and what I use A bit of 4mm mild steel is likely to come in...

No reason to remove pistons at this stage or lift the cylinder off. Valve rods should unscrew from the valve gear below. Charles, I was...

You are going to need to make it from Drill rod and then harden it (possibly temper too) Though I'd be cutting those tapers with a...

The small launches tend to run steel boilers that can make 200plus psi these will work with say a Stuart Swan or Cygnet and I don't...

Answer to #201 As the OP is in Australia they have a limit of 100psi for model boiler so the one he wants to build can't go above that...

Well I thought that was the whole idea to design the missing bits for Chris's engine not show what has been read in books about full...

So here is a comparrison between the height of the cavity in the valve and the ports for a number of model compound engines. Note in...