The outer cylinder pedestal has an interesting shape and as I do not have the casting for this I needed to make it up. I am using a piece of flat bar drilled 8BA clear at the right distance to mount two 6.35mm OD 8BA threaded pieces of steel dowel on to it. Between which I will mount the remains of a piece of slightly wider steel bar, which has been drilled 6.35mm at the right distance to slip over the tops of the two dowels. this is then silver soldered together. And (other than getting the height wrong on the first one
) these are then milled so that one fits inside the other. I am deviating from the drawings here as the original engine seems to have round bearings outsides to the main bearings while the drawing shows square
This means that the top and the bottom of the bearing pedestal have to mount together rather than leaving a square hole for the main bearing. Later they will be bored to suit the bearings.
I am using brass for the main bearings, this is not really an ideal bearing material but this engine will not be run much and the cylinder is bronze so I want a different material for the bearing and they are easy enough to make a second set if I do wear the first set out
The big bearing measures 16mm outside so I could not use my stock piece of 12.7mm brass flat bar that I have already soft soldered together for this task but had to cut down a piece of 19mm square
The trick with these bearings is to turn the outside first and once mounted inside a collet bore to suit. If you try boring without any outside support the soft solder may allow the two to open up and the result is a useless piece of scrap
The bits are very slowly coming together... I just wish I had more time
Jo