8mm Forum: B&H TQ II / 1655 reel arm problem

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Posted by Clive Carmock (Member # 347) on August 12, 2012, 02:09 PM:

I have a Bell & Howell TQ II projector, model 1655 that has been working perfectly until recently. I was running a 1200 ft film and found the part way through the take up reel stopped rotating. Having investigated further there is a weakness in the drive to both the take up and feed spindles in forward and reverse respectively.

I have just spent some time opening up the machine to see what is going on and find that there is a pair of white nylon gears on a common shaft. The one furthest into the machine is engaged when the rewind button is pressed and the outer one is used to drive the gear train to the reel arms. This gear appears to be slipping when the load increases. See picture below - the gear in question is the one I am pointing to.

I assume this might be supposed to slip under load, though thought that slippage was provided elsewhere in the mechanism.

I have not been able to remove this yet as the circlip is of the type with two small holes and I need to get a tool to remove it.

Does anyone know if this is a common fault? is this gear supposed to slip?

Any help appreciated

Regards
Clive

http://img214.imageshack.us/img214/9388/photo1zp.jpg

PS apologies Imageshack has rotated the image

Posted by frank arnstein (Member # 330) on August 30, 2012, 04:43 AM:

Hi Clive
The gear you say is slipping shouldn't slip. Its driven by the plastic worm gear beneath it. These are well known to become cracked and then they won't drive properly. Sounds like you might need to get it overhauled by a specialist as its no easy job to replace a worm gear. Often its cheaper to just find another projector that runs OK.
Have a close look all around the worm gear to see if its cracked.

dogtor frankarnstein [Razz]

[ August 30, 2012, 05:59 AM: Message edited by: frank arnstein ]

Posted by Clive Carmock (Member # 347) on September 02, 2012, 10:13 AM:

To followup on this - I have managed to fix the problem. What had happened was the clip had allowed the outer of the two gears to move a little towards the end of the shaft it is mounted on. I removed the clip and gear and realigned it with the small square metal ' key' that sits on the shaft below it and then replaced the clips tighter against the gear.

This has fixed the problem.

It has also had the side effect of fixing the problem whereby the rewind gears woudln't 'latch' when the rewind button was pressed, so I had to hold the button down through the rewind. Now it latches again.

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