HP Thermal Printer Paper Advance Repair (Additional hints))

[Hiwi]

Hi,
since i cannot post in the articles forum i will post here some additional hints.
There were many questions about repairing the paper advance rollers.

1. How to cut silicone tube?
Since i mentioned that cutting doesn't have to be absolutely exact, i will describe my method:

I have a mini drill from proxxon, which is high precision. I take a milling cutter and clamp it reverse into the drill chuck, so that the shaft is below.

The diameter of the cutter is appropriate to the tubing. Then i cut the tube with a sharp cutter (I use hardened steel blades)

2.Which tubing should be used?
I take standard silicone fuel tube for aeromodellers engine, which you can by from tower hobbies or dubro, amazon, ebay...
The outer diameter is a bit over 7mm, the inner 3.2mm. I think it is a 7/3 silicone tube.
Other types may work either. The outer diameter when mouted should not exeed 8.5mm

Ralf
   
   

[John Garza (3665)]

Looks great Hiwi!

You are correct about the low tolerances. You are not making one for mag cards. I have repaired several Topcat printers in years past by just 'eyeballing it' and slicing tubing by hand with an X-acto knife. Never had a problem.

Though when I used to repair card readers with tubing (that is, back when the manufacturing tolerances were good. Now they are not and you frequently get a batch with inner and outer diameters being non-concentric leading to irregular card movement) I used the drill bit method to ensure level precise cuts.

-J