I could measure up one of the new machined from solid ones but whether they are relevant to your castings I don't know. One thing which should be realised is that the holes in the centre of the original Electron plates was larger that the diameter of the hollow axle. The reason for this was so that upon assembly one could apply the brakes to centre the shoes within the drums before tightening the tommy bar axle. I tried to persuade the manufacturer of the new plates to do this but without success. The disadvantage of this is that upon dissassembly there is a tendency for the whole lot to fall apart and onto the floor. Rather like the original cup and cone head races. One person I know who used the new type brake plates, but with the 8" diameter brakes, machined back the centre thickness of the brake plate and then used a nut to tighten it up. Let me know if you think the measurements of the new plates is of any use to you.
Thanks for the offer. I think Bill is correct that I can figure out most of it by measuring a steel plate. That said… any measurements would be reassuring, even if its just the thickness ( depth) of the axle bore. I would assume… that all of the measurements on the inside of your plates would be the same as mine.
Thanks for confirming the larger axle bore diameter. I knew that was done with steel plates and have my special thin spanner in the special thin spanner drawer.
Just wasn’t sure about alloy plates. I did spend a lot of time obsessing about the axle bore and made sure it was straight, round and right on .750” , but this was because I’m using that for datum and didn’t want to replicate the Slater plates.
Once this mess is together, I’ll trim the shoes on the lathe…. and can open up the axle bore if necessary.
