21 Jun
2025
21 Jun
'25
10:59 a.m.
On Sat, Jun 21, 2025 at 6:49 PM Anders Nelson via cctalk
<cctalk(a)classiccmp.org> wrote:
Oh right you wanted paper tape specifically.
I sketched up a design a few years ago for a punch with horizontal plates
that slide in and out between the punch pins and a common, cam-driven
armature. I'm an EE not ME so it never went past a sketch, but surely you
could make one with a single motor to both punch and advance the tape.
That sounds rather similar to a Teletype BRPE or rather
smaller/slower) a GNT model 34. Both of which have one motor to drive
the punch crankshaft and operate a ratchet to advance the tape. There
are many others that use the same idea but I'd have to dig out service
manuals to check.
The Facit 4070 might be easier to reproduce -- a (rotary) solenoid to
operate each punch pin and a stepper motor to move the tape.
The main problem with making a paper tape punch is the actual
punch/die assembly. They have to fit very accurately to give clean
punching and be the right diameter to make holes of the right size.
Oh, and you need to harden them properly.
-tony