16 Oct
2018
16 Oct
'18
4:21 p.m.
From: Guy Dunphy
The mechanics has no adjustment or spring tension on
the pinch roller
positions. ... all the spring is in the rubber of the rollers.
But how much squish?
...
I'm hoping someone might have some knowledge of how much punch card
reader pinch rollers should press against capstans. Does 0.2mm squish
seem right
To produce a given force on the card, the dimensional amount of squish needed
would depend on the rigidity of the material, no? A stiff material would
need/want less than something soft, I would think.
Noel
16 Oct
16 Oct
6:54 p.m.
At 07:21 PM 16/10/2018 -0400, you wrote:
Yes absolutely! This is why I chose a casting silicone product with (supposedly)
a duro of 60 Shore A. Which is close to car tire rubber (60 to 70.)
Since the original rollers were rubber, I'd assumed they probably used some
standard grade of rubber and were fairly stiff too.
It's also why the mold structure I'm making will hopefully allow repeated
attempts using different materials if first try doesn't work.
Later today I'll post the photo of the rollers, with dimensions derivation.
It implies the original rollers are fairly stiff material.
Guy
From: Guy
Dunphy
The mechanics has no adjustment or spring tension
on the pinch roller
positions. ... all the spring is in the rubber of the rollers.
But how much squish?
...
I'm hoping someone might have some knowledge of how much punch card
reader pinch rollers should press against capstans. Does 0.2mm squish
seem right
To produce a given force on the card, the dimensional amount of squish needed
would depend on the rigidity of the material, no? A stiff material would
need/want less than something soft, I would think.
2258
days inactive
2259
days old
1 comments
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