4 Sep
2011
4 Sep
'11
4:49 a.m.
-----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:
It's HP-IB. Unfortunately one of the thumbscrews is missing from the GPIB
connector.
to
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. 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.
may well
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.
http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1982-12.pdf
-Rik