robh82 wrote: ↑Tue May 10, 2022 11:26 am
Hi Terry,
I read that with great interest – the cork lining idea is brilliant. I might try it one day!
I'm very happy with it for a number of reasons, robh82. The shorter slide is much easier to make, makes the head lighter, avoids the harshness I associate with full-length slides, and of course satisfies the original aim of coming up with a slide that doesn't cause cracking in dry climates.
Yes, you're right about the convenient supply of tubing. I do come from Birmingham, England, where there's still a good manufacturing trade in materials, so I might have some luck, we'll see.
Well if not Birmingham, where? I was able to get something like 4 metres of sterling silver tube drawn in Melbourne, so that's promising.
I was thinking of trying something like a 1 ton arbour press with a solid die attached. I hadn't thought about how hard it would be to get the mandrel out of the tube afterwards!!
Just something to think through, ideally before you end up with the mandrel stuck inside the tube! You could hammer it out, but since you'll need your arbour anyway, might as well have a second die that is just able to pass the mandrel though. It can catch and hold the leading end of the tubing as the press pushes the mandrel out through it.
Regarding the sheet brass approach, when you say 'drawn to final size', do you mean by hand over a parallel mandrel or triblet of some kind?
I must admit it's been a while, and I'm struggling to remember what I did. I certainly have a few punches and dies down there in the workshop that suggest that's what I did.
Of course my job is made easy by the short slides - the longer inner one is only 60mm long, the outer one 40mm. That's much easier than having to draw a full-length slide as used back in the 19th century! By comparison, the head slide on my old Nicholson original is 200mm long!