[GreenKeys] 28 ASR Typing Reperforator Print Hammer Replacement

[Mark J. Blair]

> On Jan 3, 2020, at 1:42 PM, Nick England <navy.radio at gmail.com> wrote:
> 
> Ahhh - I knew I had been through this exercise before - here are photos plus a readme with installation notes
> http://www.navy-radio.com/tty/lpr-hammer/


Fantastic! Those pictures are very helpful. I don't know yet how well the Ninjaflex filament that I have will work for this application, but I should have enough now to design a CAD model of the hammer, at least.

I'd prefer to print with the slot along the Z axis. That would mean that the lower chamfer of the hammer face would be printed over removable support. I think it may work better if I print without the lower chamfer (or even without either of them?), and then cut the chamfer(s) with a razor blade.

There's a bit of residue of the print hammer left in my keyboard punch, and I think I found another piece of it while cleaning. It's hardened enough that I mistook the loose piece for a bit of broken off phenolic insulator. I unscrewed the entire hammer assembly and the sliding bit which positions the ribbon from the bronze chunk which holds the typewheel shaft. I wanted to get the lever on which the hammer mounts out so I could measure it, and removing the whole assembly seemed like it would be easier than disassembling the fairly complex stack of levers, spring, and felts on the hammer's pivot pin.


-- 
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/