Sometimes during the movie the film "bubbles" out from between the brain rollers and this loop of film sticks out. It's hard to explain. (I can't post a pic right now. Maybe later.) I'll try to explain in words...

Show is threaded and started normally. Runs through trailer all right. The policy trailer runs and you recheck everyting before walking away. A while later you come back and you find that as the film goes between the first and second roller some "slack" has developed. Instead of going tightly around the middle roller, it sticks out a few inches to the right side and then goes back between the second and third roller and pays out normally (Most of the time) Sometimes a loop of film as big as six inches forms, which starts to get caught up in the roller shafts, causing catastrophe.

Rollers are all good w/ no burrs. Springs are all tight and pulling the rollers closed. Rollers turn freely w/o binding or catching. (The "clock springs" under the middle roller have all been removed.)

The funny thing is that it seems to happen only when the film is paying out from the middle deck.

Could it be a "hitch" in the payout platter? Maybe there's a bad splice in the print that catches somehow? I will try swapping brains to see if that helps but I don't think it will. The same brain has been used on the top middle and bottom decks. Only happens on the middle, or so it seems. I have only seen it on the middle deck, anyway. I have also asked the regular Usher-B's if it has happened on other prints and they seem to think it has.

My dominant theory is that there's a crummy splice somewhere. The reason it happens on one deck and not the other is because of the difference in film tension from deck to deck.

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By the way, for any theater that has wobbling black roller problems, replace them with Christie's green rollers and then you can forget about ever having to deal with it again.

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On the springs, they were considered necessary for any installation where the platter was farther apart from the projector than 8 to 10 feet. Personally, I've set up platters about 15 feet away from the projector without the spring and all was just fine and dandy. However, I can remember one particular installation that even though it was a straight shot to the projector, required one jumper roller, as the film had to travel about 30 feet. A jumper roller in those instances is far better than having to deal with that #~(&!\@ spring. Ever notice that no Christie 70mm roller has the capability to have that spring in it? I can just imagine the number of film breaks that would've come from it back in the acetate days. Many theaters had enough trouble making it through a day's performances back then with 70mm. Most of it was due to poor gate/trap alignment and short twists between rollers, though...basically the installation engineer's goofup!

Then again, people seem to think that film cannot be stretched more than that golden 8 to 10 feet rule for interlocking either.

I found that one of the spacer washers under the rollers was missing. Could this have been a factor? I was only able to stay for part of the first show of the day but I think it's okay now.

Michael, the backtension is there for a reason. Shipping out a film that is not tightly and smoothly wound is just asking for trouble. I have never achieved what I consider to be an acceptable breakdown wind from any platter that disengages the motor for break down. I have also witnessed many prints broken down with the motor disengaged having cinch mark scratches on the print that were not there on the final showing, but some platters (example: Strong) were designed to be used in this manner. A hand is not good enough. I assume you learned on Strong platters, as most people who do not understand the reasoning for the backtension generally have learned on them and it is a new thing to them which just doesn't seem necessary. Strong's latest generation of platters certainly provide smooth payout and takeup operation, but I sincerely hope they will take this issue to the R&D table as the failure to not provide any form of backtension upon breakdown is the main reason why I will not install them.

It's all a matter of CLOSELY regulating the speed and using your hand (with appropriate padding, for safety) to apply just the right amount of "braking" pressure as the you slow the machine down.

You have to start out VERY VERY slowly or you will "snap" the film upon start-up and then you GRADUALLY work up to normal working speed. ( Which, by the way should never be more than 2/3 to 3/4 of the top speed of the machine.)

Use your hand to put just enough drag on the platter to keep the film tight. No more. When you're up to "working speed" you can take your hand away.

When you get to the end of a reel you reverse the process... slowly bring the speed control down to a stop, applying just enough drag to keep the platter from over-spinning and backlashing the film. By the time you get to the splice you should already have the platter speed down to a "crawl". You should never have to "STOP" the platter with your hand. It should be almost ready to stop by itself. Like I said, your "braking hand" is only used to apply DRAG.

(The malfunction shown here was simulated in the interests of time and clarity.)

I'm assuming that the cause was the 3rd roller was dragging just a little bit, creating a pinch point in the film path.

When I disassembled the brain, I found that the 3rd roller (the one in back) had it's spacer washer missing. That and all the shafts were pretty icky-looking. I cleaned them up and reassembled with new rollers. I put the proper washers under each roller, too. Haven't heard any negative reports yet.

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