GS 1200 motor belt repair

[Chip Gelmini]

Can someone give basic instructions to either tighten loosen adjust or replace the basic motor belt inside this beast I've got one that is clanking really really bad terrible noise and I have to do something about it.....

[Paul Adsett]

Chip, it's unlikely that the belt needs to be replaced, they seem to last forever. But they can get noisy and produce a thumping noise due to slippage. Wet a cloth with 70% or more alcohol and wipe the belt until any grease or black debris is removed, rotate the shutter by hand so that you can get the full length of the belt clean. Keep wiping until the belt leaves little or no debris on the cloth. This should remove the noise.

[Chip Gelmini]

Thanks very much for your tip. It indeed had some crud come off on to the rag but it didn't totally help the issue.

I did find some movement of the motor shaft that seemed to go torwards the film trimmer and to the rear take up arm.

Thinking the pulley may have moved over time I readjusted it closer to the motor and the noise was worse.

So I moved it again torwards the film trimmer making sure as best that I could see that the belt and pullies were ligned up as straight as they could be.

Upon trying it the third time it was nice and quiet. I closed it up and gave it a 20 minute burn in test and so far so good.

In your opinion please advise if it seems logical or should I expect something else to happen based on the repair that I did.

thank you in any event for your advice I'm not very confident as an Elmo technician especially with the GS 1200 but perhaps this time I may have very well been successful!

Chip G

[Chip Gelmini]

Just out of curiosity

that bad noise I heard

could it have been the movement as I described above of play in the shaft at such a high rpm we would hear it but not see it

otherwise how would it be possible that a simple rubber belt could make such a clanking noise

especially when adjusting the pulley one way or the other either the noise goes away or the noise gets worse

?

[Lee Mannering]

Chip you sure it's not the idler wheel which sits on the capstone flywheel? Dont want to drag you in the wrong direction tho.

Changed my GS1200 belts for new ones last year as the oldest was 1983 so approaching 40 years! Genuine new belts over here are £10.
I work on the principle a car timing belt should be changed every 4 years.

[Chip Gelmini]

It was the motor belt, pulley, and shaft assembly. As described above.

Thanks for the suggestion though.

[Paul Adsett]

Chip, I would also recommend that you apply ONE drop of synthetic oil to the bearings of the main shaft of the intermittent mechanism, and also apply a small dab of molykote grease to the innards of the cam plate, using a long thin wooden stick. This should minimize the load on the motor and drive belt.
If the motor pulley is not perfectly aligned to the shutter pulley the drive belt tension load on the cam shaft and motor bearings will no longer be purely radial but will have an axial component, which the bearings may not like. Lubrication will help a lot.
The GS1200 is a fussy beast. I have had the noise problem you describe, and just removing the belt and putting it right back on has usually eliminated the problem for a long period of time before it starts kicking again.