How did they do that?

I've just been looking at a beam compass on ebay, #2227638979, and the knobs
have been knurled so that the knurling 'curves round ' the knob ... does
anyone know how this was done? ... has anyone done this themselves? I'd
like to know as i have an old mechanism with a knob like this missing and
would like to restore it.
TIA to anyone shedding light on this problem.
Peter
Reply to
peter.grimwood
Loading thread data ...
Probably a special tool that was made for the job, like a form tool but with knurling cutting edges.
Some of the old stuff is truly nice to play with. I have just bought a nice Cambridge Instruments PH meter on ebay, and if it is anything like the AC Wattmeter by the same company that I already have then the feel of the controls and the wooden case are lovely, makes a very nice and interesting ornament.
Peter
Reply to
Peter A Forbes
formatting link
concave knurling? Straight cut pattern Lionel
Reply to
Lionel
The last Cambridge (galvanometer) wattmeters I dealt with (two pairs on two different sites) had scales a yard long and sat on four foot height concrete tripods. I assume you are not talking about the same beast!
Mark Rand RTFM
Reply to
Mark Rand
You could mount a convex knurl in a ball-turning attachment (similar to
formatting link
with it's axis closer to the rim than the centre, and gradually work the knurl round by hand.
Rather you than me though - I can't even get straight knurling right most of the time :(
Guy
Reply to
Guy
Cambridge Instruments, wow that's a name I've not heard in a long time, my dad used to work for them, I remember the open days they had as a kid, I used to love them. Nothing to do with your conversation at all I know.
Reply to
David Griffin
No problem, it relates to the original post which WAS on topic :-))
Just bought another CI device, a Cambridge Instruments PH tester on ebay, equally nice and those large tactile control knobs (getting into anorak mode now!) just asking to be twiddled!
Picking it up tomorrow from the seller :-)) have a look here:
formatting link
Peter
Reply to
Peter A Forbes

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.