The Museum of HP Calculators

HP Forum Archive 17

[ Return to Index | Top of Index ]

Repairing the 9820 printer platten -- Thanks!
Message #1 Posted by Tony Duell on 10 Aug 2007, 1:34 p.m.

I would like to post a public 'Thank You' to David Smith and Katie Wasserman.

Some time ago I asked about repairing the platten roller in an HP9820 internal printer (same mechanism as in a 9810), and they both suggested 3M 'Cold Shrink', a material I'd never heard of before.

Recently I got round to ordering some from RS Components (this is not Radio Shack, it's a large industrial components distributor in the UK). I discovered that the smallest diameter that RS sell is, in fact the same Cold Shrink as the next size up, but the kit also includes a couple of rubber sleeves that you put on first. It's this kit that's ideal for this platten.

After dismantling the printer and cleaning off the goo, force the 2 rubber sleeves onto the original spindle (so that they touch -- a single longer sleeve would be better, but that's what you get). Then clamp the spindle in a vice, put the Cold Shrink over it, and start pulling out the 'support helix'. When you've put about half the length down, cut it round with a knife, slide the remainder over the bit you've just put on, then pull out the rest of the 'support helix'. In the end you have the spindle covered by the rubber sleeves and two layers of the Cold Shrink.

Then all (!) you have to do is trim it to length. I put the spindle in a lathe, and while turning the lathe by hand used a sharp knife, guided by the toolpost, to cut it. If you do it that way, don't even think of turning it 'by power' unless you want bits of knife embedded in you!.

Anyway, the result is a roller of almost exactly the right diameter, which grips the paper well.

Pity I've now got printhead problems, but that's another story..

      
Re: Repairing the 9820 printer platten -- Thanks!
Message #2 Posted by Vincze on 10 Aug 2007, 7:34 p.m.,
in response to message #1 by Tony Duell

So is the cold shrink like a rubber material?

Also, for those who have thermo printers for like 28C, 29C, 19B, 48GX, etc, is it easy to find thermo paper for it or must one look for surplus. Meaning, can I go to office supply super store and get paper?

            
Re: Repairing the 9820 printer platten -- Thanks!
Message #3 Posted by marais on 11 Aug 2007, 1:58 p.m.,
in response to message #2 by Vincze

Hi Tony, thanks for this report! I have a similar problem and might give it a try this winter. Regards, and keep the good work up,

Andreas

            
Re: Repairing the 9820 printer platten -- Thanks!
Message #4 Posted by Katie Wasserman on 11 Aug 2007, 2:05 p.m.,
in response to message #2 by Vincze

Quote:
can I go to office supply super store and get paper?

Yes. Not all stores have this in stock, but you can get it from their web sites. Any thermal 2-1/4" x 85' roll should work fine, I've been using the NCR brand .

                  
Re: Repairing the 9820 printer platten -- Thanks!
Message #5 Posted by Vincze on 11 Aug 2007, 7:09 p.m.,
in response to message #4 by Katie Wasserman

Thank you so much Miss Katie. I hear many wonderful things about how you great HP collector. :) Now I wish I can buy printer without someone outbidding me.

Your friend, Vincze.


[ Return to Index | Top of Index ]

Go back to the main exhibit hall