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82341A - replacements for rubber wheel and Roller

PostPosted: Tue Apr 10, 2018 9:38 am
by Drulli
Hi,
both of my 82341A printers now suffer from a poor paper advance function. I disassembled one printer (which otherwise shows no defects or problems) and pulled the pinch roller (9) and the paper advance (16).
Replaceable_Parts_hp82341A_No.9_No.16.JPG
Printer Assembly exploded view


The rubber wheels are not very soft anymore even though I rejuvenated the rubber with CaiKleen http://store.caig.com/s.nl/it.A/id.1671/.f?sc=2&category=179one year ago. Otherwise they don't look too bad.
I measured the diameter of the wheels: d_out:7.86 mm, d_in: 5,22 mm. The width:2,11 mm.

pic3.jpg
Paper Advance


The Roller pinches look pretty worn out, at least one of them.
The diameter d_out is: 4,38 mm. The width is 2,11 mm.

I guess that those values might sound somewhat more reasonable, if expressed in imperial units. How would that be expressed in inches?? 1/20 of an inch or something like this??
Does anyone has the hp specification, the original values of the wheel and roller?

And.. more important, does anyone knows replacements for the items, or can point me to an article where someone has explained how he made a replacements?

Thx!

Re: 82341A - replacements for rubber wheel and Roller

PostPosted: Tue Apr 10, 2018 7:19 pm
by Garth
Thanks. This is good information.

Drulli wrote:I measured the diameter of the wheels: d_out:7.86 mm, d_in: 5,22 mm. The width:2,11 mm.

<picture>

The Roller pinches look pretty worn out, at least one of them.
The diameter d_out is: 4,38 mm. The width is 2,11 mm.

I guess that those values might sound somewhat more reasonable, if expressed in imperial units. How would that be expressed in inches?? 1/20 of an inch or something like this??

We would normally go in thousandths, sometimes pronounced "thou" for short, or "mils" (from definition #2 at https://en.wiktionary.org/wiki/mil#Noun) So:

    7.86mm = .309" (which we might pronounce "three hundred nine mils)
    5.22mm = .206"
    2.11mm = .083"
    4.38mm = .172"
I should get my HP mini printer out and try your solution on it. I haven't even powered it up in a few years. For printing from my 41 or 71, I normally just go through one of the HPIL interface converters, to the big Epson printer. My HP Thinkjet printer quit working years ago. I suppose there's a problem with the flex circuit connection to the print head. It goes through the motions, but there's absolutely no printing. I've tried with lots of different cartridges, all primed, contacts clean, etc..

Re: 82341A - replacements for rubber wheel and Roller

PostPosted: Thu Apr 12, 2018 7:12 pm
by Drulli
HI Garth,
thanks for the little lesson in imperial units smaller than 1. Very helpful.

The measured values sound a bit more reasonable when expressed in inches, close to a x*tenth of an inch.
Thus I will look for replacement in inches instead of mm.
Not too easy, I guess. Patience and creativity is needed, if I don't find any proper "donatores".

Concerning your printer its difficult to say what the problem. I looked for a service manual but couldn't find it on the web.
The Number seems to be 02225-90079. You can google it. Maybe you have more luck than I.
You might check the signal lines with an oscilloscope, whether there is life or not.

A 2nd device would be helpful for comparison.. :mrgreen:

Re: 82341A - replacements for rubber wheel and Roller

PostPosted: Thu Apr 12, 2018 10:58 pm
by rprosperi
Garth wrote:My HP Thinkjet printer quit working years ago. I suppose there's a problem with the flex circuit connection to the print head. It goes through the motions, but there's absolutely no printing. I've tried with lots of different cartridges, all primed, contacts clean, etc..


ThinkJet ink is corrosive and if (when) a cartridge is left for a long period in the print head "socket", the ink slowly dissolves the metal contacts in the carriage connecter that interface with the cartridge face. If this has happened, there is little you can do to repair it, you need to find another machine to scavenge an undamaged carriage/socket.