24 May
2012
24 May
'12
11:13 a.m.
I agree that home-made paper tape readers seem pretty easy, as projects
go. But what I'd REALLY like to see is a home-made paper tape PUNCH.
That's got to be tricky, even for a machinist! :)
It's a lot harder than a reader, but I don't think it would be imposible.
I've worked on many commercial paper tape punches, and most, if not all,
of them could be reporduced by a good model engineer (== home shop
machinist).
There seem to be 2 basic ways to make such a mechanism. The Facit 4070
typifies one, the GNT34 ( and BRPE) the other. The Facit 4070 has a
rodary solenoid and link rod for each punch pin, and a steper
motor/capstan to move the tape.The entire punchign force comes from the
solenoid
The latter haev a motor drive mechanism, and a set of small solenoids (in
the GNT34, they llok like the coils from 'continental cradle relays')
whci engange the mechansim with each pin, in many cases by sliding a
spring-steel 'interposer' bekhind the pin, thus forcing the pin to be
moved when the mecanism does.
I am not sure which would be easier to make.
However, the reader is probalby the more useful device in that it lets
you archive paper tapes onto modern machiens nd thus to the web, etc. If
anyone wants to run them on the oriignal hardware and doesn't have a
punch to recreate paper tapes, it wouldn't be hard to make a paper tape
reader emulator (reding the data from something like an SD card) for the
classic computer.
-tony