3 Dec
2024
3 Dec
'24
1:38 p.m.
On Dec 2, 2024, at 4:00 AM, David Wade via cctalk
<cctalk(a)classiccmp.org> wrote:
Folks,
I have been trying to restore a manual card punch. The type with 12 "Buttons"
or "Plungers" that operate a lever which pushes a punch "pin" through
a die to create a hole in a card.
Its almost identical to this one:-
https://www.computinghistory.org.uk/det/38019/ICL-Hand-Key-Punch-Card-Machi…
so despite lots of cleaning some of the pins stick down. Does any one have any
suggestions how to clean the small square slots?
Any idea how the holes were made?
Dave
G4UGM
Do you mean the rectangular holes that guide the punches, or that receive the punch below
the card (the die)? Or are there square rods that carry the buttons, in a square hole?
The obvious solution would be a solvent. Paint thinner might work. If not, you may want
something stronger, but if so you'd need to remove any plastic parts (like the
keycaps). Laquer thinner is potent, I use it a lot, but only on insoluble items.
Rectangular holes can be cast, or machined with a broach. The same goes for square holes,
but in addition it's possible to drill square holes, using triangular drills. Watt
Brothers Tool Works has made these for ages (see
https://www.scribd.com/doc/67999953/Watts-Bros-Manual).
paul