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Author
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Topic: Ballantyne gate problems
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Paul G. Thompson
The Weenie Man
Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000
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posted 12-23-2000 04:34 PM
Charles, I presume your splices done correctly. Does the machine stay in frame as the loop shrinks? If the upper loop is getting smaller, you might want to check the pad rollers on the upper feed sprocket for "goose egging", for a lack of a better term. Also, check to make sure that he pad roller adjustment is correct. Some people use two thicknesses, as the manual points out, some people use only one film thickness. I recommend two thicknesses. Be sure the adjustment is the same on both rollers. Also check the sprocket for hooking, broken teeth, etc. If you have to replace the sprocket, use a VKF.  If the loop is getting bigger, it sounds as though the gate adjustment screw 2784-R backed itself out quite a bit. That will also give an obnoxious picture jump on the screen. That is the accentric screw that allows fore and aft adjustment of the casting 10535. If that adjustment appears to be ok, someone may have dropped the film gate and pressure pad assy on the deck and sprung the lower portion that holds the intermittent sprocket shoe. If this is the case, the sprocket shoe may not be making contact (or very little) with the film when the gate is closed. It can be restored back to its orginal position very easily. However, be careful. If you "restore" it too much, that lower portion of that assy could come in contact with the film, and seriously scratch the film stock. Seen this happen a bunch of times, unfortunately. 
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Randy Stankey
Film God
Posts: 6539
From: Erie, Pennsylvania
Registered: Jun 99
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posted 12-23-2000 11:11 PM
I have to agree with the experts here.If you're blowing a loop it's likely because the film is slipping off a sprocket. Checking all the pad rollers is the first step I'd recommend. (But Paul recommended it first!) Second thing I'd think of is whether or not there are any busted-out sprocket holes in the film. Like Paul asked, "Is it staying in frame?" That's a major telltale. Other thing I'd ask is, "Does it always happen at the same place in the film?" If so, then it's almost definately due to busted-out sprocket holes.
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Pat Moore
Master Film Handler
Posts: 363
Registered: Mar 2000
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posted 12-24-2000 09:53 AM
Hi; As a Ballantyne guy I have to look hard at that upper sprocket and pad adjustment as well. That's the only thing that can make that upper loop get smaller. Logical choice, as it sounds like there's not been too much maintenance applied here.Depending on the generation of PRO35, that pad assembly can be a bit tedious to adjust. The early version had too many adjustments.Assuming the film is properly guided into the projector from the top, adjust to two film-thicknesses or a little more -- never less. Are the sprocket teeth hooked or worn abnormally? Merry Christmas! Pat
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Paul G. Thompson
The Weenie Man
Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000
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posted 12-26-2000 11:31 PM
Charles, when the splices are made, is someone taping over someone else's tape? If so, that can cause a problem. When the film is assembled, peel off the tape that was left behind from a prevoius splice job. If you can't peel it off, just cut out the frame. Be sure to tape both sides of the new splice to prevent it from hinging. Also make sure the tape does not hang over the edge of the film after the splice is made. If it does, Use a pair of scissors to trim it, and get some new parts for your splicer. Also, make sure the register plate on the splicer is not worn out. If the splices are otherwise perfect, then there could be a mis-alignment of the studio guides (P/N 3521, 3553, and 2832), and/or the lateral stabilizer plate,(P/N 3522). I think most of the Marcus's Ballentines have that style gate that use the parts I mentioned. The lateral stabilizer plate has to be removed and cleaned from time to time because of crud build-up which would prevent that plate from seating squarely. Also, there could be a gross mis-alignment of the entire gate assy with reference to the intermittant sprocket. Ballentine makes gate gages to check that. Your service engineer is probably equipped with those. Last but not least, your film trap tension may not be properly set. The Pro-35 manual explains very nicely how to adjust that. Pat Moore, did I leave anything out?
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