16 Oct
2018
16 Oct
'18
9:18 a.m.
Den tis 16 okt. 2018 kl 11:52 skrev Guy Dunphy via cctalk <
cctalk at classiccmp.org>:
Previously: Manual for Documation TM200 punched card
reader
Restoration of the mechanics of my TM200 punch card reader progresses.
There's a writeup here:
http://everist.org/NobLog/20180922_data_in_holes.htm#tm200
Currently I'm machining a mold to cast new pinch rollers - and there's the
rub (ok kill me.)
The old rubber rollers were decayed to gunk, so there's no chance of
measuring their original dimensions.
From the mechanics, if they were just touching the steel capstan rollers
they'd have been 27.1 mm Dia.
The mechanics has no adjustment or spring tension on the pinch roller
positions. Their shafts are in fixed
position, so all the spring is in the rubber of the rollers.
My hardened rubber rollers in my M200 measure 26.8 mm.
/Mattis