Restoring the BT Cheetah 85

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Re: Restoring the BT Cheetah 85


Beitrag von M1ECY »

Just a couple of little update points - the rolling restoration continues (ok, so I repair it when things break....)

The paper transport drive belt exploded on the printer last week - No great drama - lots of bits of decomposing rubber and a very fine steel cable wrapped around the drive stepper motor.

I removed the printer assembly from the machine and brushed out all the rubber debris, and unwound the belt cords from the drive motor.

I then soaked the aluminium drive pinion in cellulose thinners to dissolve the sticky mess that the 30+year old drive belt left behind.

I cleaned the paper roller drive gear, and also gave the drum a good clean with some isopropyl alchohol this has helped to clean the last of the dirt from years of storage in a barn.

A new belt was ordered from RS Components - Part Number 474-5050, can also be found by searching for 6T2.5/200.

To fit the belt, the two clips that secure the paper roller to the printer need to be released - they can just be flicked out with a small screwdriver., the roller is then gently lifted clear. the three securing screws for the drive motor need to be loosened - this gives some slack to allow the new belt to be slipped over the pinion.

Tighten the screws once the belt is fitted to the pinion and roller, and then put the roller clips back into place.

Problem solved - Printer now feeds paper again :)

Whilst I was "Under the Bonnet" I fitted the original double current card, and connected this to the UT55A V.21 to Double Current converter - this works flawlessly with I-Telex, and is another way that Double Current machines can be connected to I-Telex.

I will leave the machine connected for a while now to see if this also cures the "Fundamental Fault" issue - the machine is built as STC intended, so hopefully it will behave properly now.
459724 SEAN G - Te Ka De FS200 - Working 24/7
666507 JONAB G - BT Cheetah 85 - Working sometimes
350470 Ersatz G - J-Term - Not Used
BT Cheetah 87 RIP.
Siemens T68d - Working - Not connected yet
778672 WSWHQ G - BT Super Cheetah - on 312526


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