Thank Per
Hi Bent, that is standard plastic epoxy filler as used on cars. Sometimes it is worth using JB Weld if I need something that can take a lot of temperature. I have also been given a tub of epoxy metal filler which I have not opened yet. While you may think of the top of a stove as being very hot relatively it isn't I doubt it will boil water and if it is hotter your fan will quickly overheat....
The power piston centre casting was also missing
So I made it up from some brass bar. I could have used a 25.4mm diameter bar and turned it down for the main body of the centre but chose to just stick on a collar of the wider diameter to save my sparse metal stocks
The two bosses are for the bottom of the links and these have been made by drilling the centre of a piece of brass 4mm (just under 2BA tapping size) and then using the side of a milling cutter the diameter of the body of the piston centre to scallop out the inner curves.
The piston centre bar can now be drilled 4mm at the appropriate point for the centre of the bosses, a suitable piece of brass tube inserted: I drilled a bit of brass 2.8mm here to take a 6BA screw to hold the bosses on. Having dampened the joints and dipped the damp bit in some flux it is ready to be silver soldered together.
Once silver soldered it can have the bottom of that 25.4mm diameter turned again to make sure it is true and the 1/2" by 26TPI thread cut using a die. The last bit being to add a bronze bush in the centre with Loctite to provide the sliding surface for the displacer rod.
I think we are ready to attach that flywheel bracket... With all the links in place it is obvious that the flange where it mounts to the cylinder casting needs a bit taken off. Once that is done the two holes for the mounting bolts can be drilled out 3.2mm (4BA tapping) and now I need to transfer those holes onto the cylinder so I need a 3.2mm diameter centre punch to poke down the two holes to mark the centres.
Jo