[personal] Re: Replacement "pick" roller for card reader

[Mike Hatch]

I've had some success with adhesive lined heat shrink tubing, scraping off 
the goo layer and using a tube size just larger than the required final 
size.

Mike.

----- Original Message ----- 
From: "Ethan Dicks" <ethan.dicks at usap.gov>
To: "General Discussion: On-Topic and Off-Topic Posts" 
<cctalk at classiccmp.org>
Cc: "Phil Budne" <phil at ultimate.com>
Sent: Friday, June 27, 2008 2:32 PM
Subject: [personal] Re: Replacement "pick" roller for card reader


> On Fri, Jun 27, 2008 at 07:12:52AM -0400, Brad Parker wrote:
>>
>> I talked to several chemical engineers about "gooey" roller and they
>> both said that once the polymer chains relax, there is no going back.
>> As I recall, they mentioned ozone and sun light being bad.
>
> That is my experience with "rubber" parts (ASR33 hammers, HPLJ paper
> pickers, TU58 rollers...)  Once they go bad, you are boned.
>
>> I've had good luck fixing tape drives with "rubber" hose used for food
>> processing equipment. I don't think I used Neoprene - I think it was
>> "Tygone". There are lots of varieties.
>
> As others here have, I have used Tygon tubing of the right size to
> refurb TU58 rollers.  For HPLJ printers and ASR33 hammers, I've been
> able to find relatively inexpensive OEM replacements, so far...
>
>> The trick was getting a small amount.  I had to buy 10'.  But I was able
>> to find one with an I.D. which matched the shaft and O.D. which matched
>> the original.  If you can, measure the original with a micrometer.
>
> Again for TU58s, since they have shaft encoders on the motors, you
> don't have to have *exact* replacments, but as it happens, the standard
> hardware tygon tubing happens to work to replace the rollers.  Paper
> pickers for HP LaserJets are almost 1" in diameter, so I haven't
> tried to sub for them, except with "genuine" replacement parts.
>
> As I've heard, if you have some refurb material that is barely too
> large, one way to reduce things is to freeze the roller material
> with Dry Ice or Liquid Nitrogen and turn the frozen rubber on a
> lathe, but I haven't tried that personally.
>
> The older our gear gets, the more important it will be for folks
> to be able to replace soft bits on their own - eventually, even the
> vendor spares will turn to goo and the only alternative to making
> parts from scratch is staring at non-functional museum pieces.
>
> -ethan
>
> -- 
> Ethan Dicks, A-333-S     Current South Pole Weather at 27-Jun-2008 at 
> 13:20 Z
> South Pole Station
> PSC 468 Box 400       Temp  -81.4 F (-63.0 C)   Windchill  -119.3 F (-84.1 
> C)
> APO AP 96598          Wind   10.1 kts Grid 44   Barometer 668.7 mb (11057 
> ft)
>
> Ethan.Dicks at usap.gov 
> http://penguincentral.com/penguincentral.html
>
>