looking for an old IBM knob from a 609 calculator panel

steven at malikoff.com steven at malikoff.com
Tue May 28 17:06:24 CDT 2019

>     On Tuesday, May 28, 2019, 10:36:10 AM PDT, William Donzelli via cctalk <cctalk at classiccmp.org> wrote:
>  Those knobs look like they are cast pop metal or zinc or something,
> not Bakelite.
> --
> Will
> They are metal for sure. Probably cast. They are smooth, though there's a bit of corrosion and pitting on them now.There's a set screw at the bottom of the back side. 
> Dwight suggest casting one. I've never done casting before but this might be a good thing to try it on.Would have to drill the shaft and set screw holes afterwards, and a bit of finish work to make them smooth.It's a cool panel so probably worth the effort if I can't find one out there
somewhere...> Bob

I agree casting might be for you the easiest way to go, then spray it. It's an unusual shape
but a good enough copy for 3D printing could be done in OpenSCAD from a few caliper measurements:
disk dia, disk rim height, overall height, dip angle, top paddle width, bottom paddle width,
top indent length/width/depth and paddle front radius ought to be enough.


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