Threaded Mode | Linear Mode

Hans-Peter · 11-14-2016, 09:06 PM

After a long search, I found a supplier for the replacement of the rubber gear in Germany.
The bore I had to increase from 2mm to 2.38mm and with some sandpaper I had to reduce the thickness by 0.1mm. But now the brass gear runs perfectly.

I have the running surfaces with little oil. Nevertheless, the printer makes noise as a saw.

Now the supply for the European HP97 printers is ensured :-)

http://www.modellbauershop.de/zahnraeder...3-30-z.php
Produkt-ID: 390760
Price €11,25

Hans-Peter

Jlouis · 11-15-2016, 02:33 PM

Thanks Han,

I'm looking for this gear for almost a year!

Cheers!

Jlouis · 11-15-2016, 02:37 PM

By the way, you mentioned "european HP 97".

Are there diferences in the gear measures between the 97's?

TIA

Hans-Peter · 11-15-2016, 06:12 PM

Not only for the European also the other Countries who would be delivered from the company.
In the other case I will make a collective order for overseas HP97, if the delivery should not go.

I think Geoff was already in a forum in the search for the gears and he wanted about 40 pieces, if I remember correctly.

HP ;-)

bernouilli92 · (This post was last modified: 12-03-2016 10:10 PM by bernouilli92.)

This gear is a better replacement:
http://www.modellbauershop.de/zahnraeder...30-z-1.php

It's cheaper and you don't need to reduce the thickness. But you still have to widen the hole.

There has been a post about it:
http://www.hpmuseum.org/forum/thread-601...l#pid53789

Tom V · (This post was last modified: 08-25-2018 04:53 PM by Tom V.)

Hi folks, hello Hans-Peter,

thanks for this valuable information!
Today I purchased new brass gears from the Modellbauershop (now it's https://www.ghw-modellbau.de/)

I hope I can finish the HP97 restoration next week

regards from Muelheim/Ruhr Germany
Thomas

Jlouis · 08-22-2018, 12:59 AM

(08-21-2018 05:25 PM)Tom V Wrote: Hi folks, hello Hans-Peter,

thanks for this valuable information!
Today I purchased new brass gears from the Modellbauershop (now it's https://www.ghw-modellbau.de/)

I hope I can finish the HP97 restoration next week

regards from Muelheim/Ruhr Germany
Thomas

Hi Thomas,

Please tell us when you finish. I have not restored mine yet and if the gears you bought are ok, I will buy them too.

Cheers

Hans-Peter · 08-22-2018, 07:08 PM

I can confirm that this gear fits perfectly and can easily be taken as a replacement.
The new gear will probably last longer than the rest of the printer.

Hans-Peter

Tom V · 08-25-2018, 04:51 PM

Hi folks,

done.... printer works perfect!

I purchased from "GHW Modellbauversand" this part:

"Stirnrad Mod. 0,3 Messing - 30 Z"
Part number #753030
each 3,15 EUR

https://ghw-modellbau.de/product_info.ph...anguage=en

The gear fits perfect, only the hole is to small
I drilled the hole to 2,4mm (we have a lathe at work)
no further modifications required!

thanks to the forum for the great tip!!!

pipesm · 12-09-2021, 06:31 PM

I just got an HP-97. The middle gear in the printer is broken. It doesn’t seem to be rubber, it is some beige plastic. It sits between the motor and printhead gear. Is this part the one mentioned above, or, do I need a different one?

Also, I get “error” when I attempt to insert a card, and the card reader seems to not engage the motor. I need to troubleshoot this more. I am guesding it sees the card, but fails to start motor. Will need to nose around with svope. Smile

Thoughts?

Thanks,
Mark

wbvreeuwijk · 12-15-2021, 03:54 PM

Hi Mark,

I recently 3D-printed a few of these gears and they seem to work ok. (the top ones are what was left of the original gears :-) )

Regards,
Bas

(12-09-2021 06:31 PM)pipesm Wrote: I just got an HP-97. The middle gear in the printer is broken. It doesn’t seem to be rubber, it is some beige plastic. It sits between the motor and printhead gear. Is this part the one mentioned above, or, do I need a different one?

Also, I get “error” when I attempt to insert a card, and the card reader seems to not engage the motor. I need to troubleshoot this more. I am guesding it sees the card, but fails to start motor. Will need to nose around with svope.

Thoughts?

Thanks,
Mark

teenix · 12-15-2021, 09:07 PM

(12-09-2021 06:31 PM)pipesm Wrote: Also, I get “error” when I attempt to insert a card, and the card reader seems to not engage the motor. I need to troubleshoot this more. I am guesding it sees the card, but fails to start motor. Will need to nose around with svope.

Thoughts?

Thanks,
Mark

Some items that may need attention - start to end:

leaf switches under keys circuit board
corrosion of key circuit board tracks
connectors between key board and CPU board
CRC chip
corrosion of cpu board tracks
connectors between cpu board and sense board
cpu power supply
corrosion of sense circuit board tracks
sense chip
battery/motor wiring to sense board
motor capacitor
motor

cheers

Tony

Kees Bouw · 12-15-2021, 09:44 PM

(12-15-2021 03:54 PM)wbvreeuwijk Wrote: I recently 3D-printed a few of these gears and they seem to work ok. (the top ones are what was left of the original gears :-)

3D printing sounds good. I think that HP manufactured this specific gear from plastic for a reason and that replacing it by a metal one may not be a good idea. Apart from that I believe in restoring calculators (and other equipment as well) as close to the original as possible.

teenix · 12-15-2021, 11:08 PM

(12-15-2021 09:44 PM)Kees Bouw Wrote:
(12-15-2021 03:54 PM)wbvreeuwijk Wrote: I recently 3D-printed a few of these gears and they seem to work ok. (the top ones are what was left of the original gears :-)

3D printing sounds good. I think that HP manufactured this specific gear from plastic for a reason and that replacing it by a metal one may not be a good idea. Apart from that I believe in restoring calculators (and other equipment as well) as close to the original as possible.

I believe this too and mentioned awhile back that it may be due to the fact that if the PIK chip or home switch failed, the motor could keep running and drive the print carriage into the printer frame and cause a motor stall and subsequent damage. It is possible that this gear is sacrificial in this type of fail.

It may also keep the printer noise low.

cheers

Tony

Paul Dale · (This post was last modified: 12-16-2021 09:38 AM by Paul Dale.)

Edit: accounted for now. I've one final one but it is longer and doesn't have the boss/peen section. It would need to be carefully cut down into two.

I've got a couple of the GHW Modellbauversand gears I'm happy to send to needy 97 owners for free. The catch is that we're in the middle of a 2300km house move and everything is in storage. There is no chance I'll be able to get access to them before May next year and possibly later.

They've been drilled out on a lathe and they work great.

Pauli