1 May
2020
1 May
'20
5:18 a.m.
I've cut Mylar tape with a Glowforge laser. It cuts very nicely but the
alignment is a major hassle, plus you can only cut ~15" of tape which
doesn't go very far. Not worth the effort. If you were to build a custom
linear drive it might work. But also very slow.
Here's a picture of a mechanical (Teletype 33) punch block. These are
quite high-precision parts with hardened pins. The pins drive through a
narrow gape for tape, into matching holes in the top of the block. On the
Teletype, the drive mechanism is slow, and the punch sits quite a long way
from the single solenoid that sets up the bits. I
assume high-speed
punches have a similar block but a more direct (parallel)
actuator.
https://photos.app.goo.gl/F6QZQE3tiKgiGB6c7
CuriousMarc has a good video showing this sort of punch in operation,
https://www.youtube.com/watch?v=yzulZaJbdUU&list=PL-_93BVApb5-84G5kmgfu…
On Fri, May 1, 2020 at 12:02 AM Anders Nelson via cctalk <
cctalk at classiccmp.org> wrote:
Hi all,
I've had a paper tape reader for a while but never had a punch to make new
tapes, and the ones i've found are not only very large but also very
expensive. So I'm toying with the idea of making an open-source punch, but
I can't find any detailed diagrams of how the mechanism works.
I'm assuming (without any data to back it up) that there is a cam, an array
of spring-levered pins, and horizontal spacers controlled by solenoids that
bridge the gap between the cam and each punch pin when called for.
Does anyone have insight into how reliable/fast paper tape punches work?
--
Anders Nelson
+1 (517) 775-6129
www.erogear.com