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Author
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Topic: B&H TQ3 specialist Auto loop former clatter
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Max Maxwell
Junior
Posts: 10
From: Worcestershire, England
Registered: Oct 2016
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posted November 03, 2016 10:05 AM
When I started using this projector again (a couple of weeks ago), I was having problems maintaining the bottom loop, even after a good clean and lubricate, so I put it down to the film I was using (I only had one!). Now I have obtained some more films, the problem persists. On the original film, the problem only happened persistently during the last 300 feet (or so) of the 1600 ft reels. However, when I put a 2000 ft reel on, the problem started happening immediately, even when I ran some film off the front reel. Depressing the auto loop lever corrected the problem for a while but often this even failed.
Sometimes the film starts jumping in the gate immediately and at other times it is just clatter from the lower loop former trigger for some considerable time, eventually leading to jumping in the gate.
I obtain the best results by
(a) Manually forming the lower loop and "inching" the drive until I can relocate the claws into the sprocket holes.
and
(b) Holding the auto threading lever slightly forward (but not locked) and maintaining it in this position whilst the film runs. (clearly not practical!)
I have studied other advice on this and other forums and have tried all of the suggestions given. Although there I found nothing for this actual model projector. I would appreciate any suggestions please.
The projector is in near mint physical condition inside and outside and when it was previously in use, it was professionally well maintained, including new (uprated) worm gear.
I am quite technically competent with mechanical devices but I'm willing to have the protector professionaly serviced if necessary
Regards. Max
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Max Maxwell
Junior
Posts: 10
From: Worcestershire, England
Registered: Oct 2016
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posted November 03, 2016 05:42 PM
Gentlemen, many thanks for the responses. The lower loop restorer seems operate as it should and isn't seized. The only parts that were stiff when I cleaned and lubricated before bringing back into service were the feed and exit rollers for the sound drum. I removed the rollers, cleaned the shafts and lubricated them before replacement.
I did try manually threading as Maurice suggested but the problem remained. The worm gear does appear to be an all black nylatron one but the projector was in regular normal use for some time after replacement and displayed no problems, so I assume it was set up correctly.
I have studied the operation carefully by slowly inching it round many times and the lower loop slowly gets smaller before eventually operating the trigger. This doesn't make sense to me because (taking the claw mechanism out of the equation for this exercise) if the film is "captive" around the upper and lower sprocket assemblies, which are in turn synchronised together by the drive gears then the film is being taken up at exactly the same rate as it is being delivered, thus the loops should remain constant. This seems to indicate that the problem may lay with the operation of the claws but the top loop doesn't seem to become any larger.
However, I am not quite sure how the lower loop restorer actualy operates. I note that as the loop gets smaller it applies upward pressure on the restorer roller, which eventually starts to oscillate noisily but what does it actually do? (mechanically that is).
I really would like to understand this and I do have the service manual but it is fairly heavy going and certainly not going to be a quick read! Then of course there are the factory supplied special tool./gauges that are needed and whilst I could easily make these, there are no dimensioned drawings of them!
Max
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Max Maxwell
Junior
Posts: 10
From: Worcestershire, England
Registered: Oct 2016
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posted November 04, 2016 05:47 AM
David, I intend to buy second projector anyway so I will certainly see what you have on offer.
Maurice, Thank you for the further description of the loop former operation, which is obvious when I think about it, I was expecting something far more complex. However I presume the operation must be synchronised so that it only pulls when the claws are retracted. Incidentally, I didn't go inside to remove the sound rollers as they are on the outside. After removing the end retaining screw they can be slid off the plain shaft, lubricated and replaced, no synchronisation is required.
It may be that the setting of the claw (or shuttle as B&H call it) is not correct but I don't know what the settings are because B&H only provide a "go"/ "no go" gauge to set this and give no measurements. The pressure plate spring tension may be an issue but I don't think it is this.
I have no problem with having a professional service and setup this projector but I do also like to be able to do things myself. I maintain and setup my own 16 and 35mm professional film cameras (Aaton and Arri) which are quite complex.
Thanks for your offer to put me in touch with a service engineer, I'll PM you for the details.
Max
[ November 04, 2016, 07:54 AM: Message edited by: Max Maxwell ]
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David C. Lucidi
Expert Film Handler
Posts: 127
From: Glenolden, PA, USA
Registered: Nov 2013
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posted November 04, 2016 09:31 AM
Max,
Couple of things to consider:
1.) As others suggested, it could be the fact that when the new worm gear was installed, the projector wasn't properly 'synched'. It's a VERY precise operation, and even being off a little can cause major problems. I bought (2) B&H projectors "new" off Ebay with worm gears replaced, and had nothing but issues. I ended up having it repaired by a professional (Richard Burgess), because the company I bought the projectors from could not properly repair it (long story for another time). Here's a link back when I had the problem, does this match your issue? Link: https://www.youtube.com/watch?v=15kxBvw2fFI
2.) The second issue I had (which only happened once), was AFTER the projectors were properly repaired. One reel of an older, dryer films would cause an occasional loop restore to occur. Does this match your issue? Link: https://www.youtube.com/watch?v=lBqhp1qhm_0
In this case, the culprit was just the one film I had, and the dryness of it was causing it to "stick" in the gate slightly. It was suggested to lightly spray the ends of the reel (edges of the film) with Endust. I actually sprayed a list mist of Film Renew instead, but, regardless, it solved the problem. Out of maybe 150 reels of film, that was the only one causing the problem in the link, and once I actually cleaned/lubed the film, I haven't had it happen since (with that, or any other reel). The Endust was suggested 'just to see' if it was a 'dryness' issue.
3.) Another thing to check and clean is the entire film path, specifically, the gate itself (where the film travels between the lens and claw). Make sure it is SPOTLESSLY clean, and make sure the spring clip (on the inside track of the gate) moves freely and is not binding up.
Hopefully this helps!!
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David C. Lucidi
Expert Film Handler
Posts: 127
From: Glenolden, PA, USA
Registered: Nov 2013
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posted November 04, 2016 10:34 AM
Hi Max,
I don't recall if it had the problem when leaving the projector running "unloaded" when I first got them (when you see the issue in video #1). The issue only seemed to happen when running film through it, and it was how got them from MagnaTech/Iceco in Florida (who I would never, EVER deal with again btw).
If you want to read a little, here's a link of what I went through with them, and further down in the post, all the things that were out of spec when I had a professional repair the projectors. Keep in mind, these were supposed to have ALREADY been "repaired" as they had new worm gears installed (they were otherwise unused).
Link: http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=5;t=001295#000000
If your problem mimics my first video, you may need to have some serious syncing/alignment done to get it working right.
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