-----Oorspronkelijk bericht-----
 Van: cctalk-bounces at 
classiccmp.org [mailto:cctalk-bounces at 
classiccmp.org]
 Namens Philip Pemberton
 Verzonden: zondag 4 september 2011 10:53
 Aan: cctalk at 
classiccmp.org
 Onderwerp: Re: HP 7470A plotter -- repairing/replacing paper feed rollers
 On 03/09/11 19:37, Tony Duell wrote:
   I've
just acquired a HP 7470A in a lot with some other gear, and it 
 Nice find!. Which version is it? There are 3, HPIB, RS232 and HPIL
 (the last being by far the rarest). Alas you can't easily convert one
 to another, there's one PCB inside, and it differs between the
 versions. 
 
 It's HP-IB. Unfortunately one of the thumbscrews is missing from the GPIB
 connector.
  I assume these are the little rollers on the
clamp arms above the
 plotter deck. 
 Yep.
  Whether a thin 'rubber' coating (for
example heatshrink sleeving) on a
 tapered hub would work, I don't know. I think I'd try that first,
 because it's not hard to make. 
 How are the rollers removed and reinstalled? I can't see any obvious way 
  remove them without damaging the clamp arms.
  Turning a tappered rubber roller is possible, but
rubber is not easy
 to machine. It helps to cool it, but not too far (I am told that solid
 CO_2 is about the right tempeature). 
 Who said anything about machining the roller? :)
 I just bought a pack of "Sugru" (a type of putty based on silicone) which
  work for this. The trick is going to be making
some form of rig to make a
 tapered rubber roller of the correct size...
 Thanks,
 --
 Phil. 
 Philip,
 This HP Journal has a few articles about the development and working of the
 HP 7470 electronics and mechanics.