This is topic What causes a print to be loose or tight? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Dave Cutler (Member # 515) on 08-14-2000, 05:16 PM:
I have Strong DMC Platter systems and some of them leave prints nice a tight and some leave them extremly loose. Does anyone know why this is?Oh, I have tried to recalibrate the trolley, but it didn't seem to make any difference.
Posted by Brad Miller (Member # 2) on 08-15-2000, 02:33 AM:
Does it vary from deck to deck on the same platter system, or from system to system?
Posted by Dave Cutler (Member # 515) on 08-15-2000, 09:22 AM:
Good question, and I am not sure of the answer. I will check that out tonight when I go in.
Posted by Mike Blakesley (Member # 26) on 08-15-2000, 05:37 PM:
Are the platters properly grounded? Problem could be static electricity.
Posted by John Pytlak (Member # 331) on 08-16-2000, 05:17 AM:
Mike:How can buildup of static charge cause a loose roll? "Winding integrity" is usually only a function of winding tension and the frictional coefficient and microscopic surface roughness (matte) of the film. Since Dave's concern seems to vary with the platter, I suspect it is mostly due to winding tension.
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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Posted by Dave Cutler (Member # 515) on 08-16-2000, 09:17 AM:
Ok, the problem seems to be consistant on a given platter system. ie all platters on one tree seem to rewind loose, or they all rewind tight. Any suggestions?
Posted by Mike Blakesley (Member # 26) on 08-16-2000, 01:00 PM:
John:That was just a guess... I've had a number of prints wrap loose over the years, and it just seems like every time it happens, the print is fairly static-y. I didn't know about the "matte" characteristic you mentioned (or more likely, I did know but didn't think of it.) The things one learns on this forum!
Posted by Brad Miller (Member # 2) on 08-16-2000, 02:21 PM:
Check your takeup elevator. Generally if the up and down movement is nice and smooth, the print will wind tighter. If there is a little bit of resistance, they will wind loose. I'd try cleaning the rods and coating them very lightly with projector oil and see what happens. Many times it's just gunk built up on them from time and usage that is the cause of the problem. Otherwise, it's generally something mechanical in the elevator out of alignment.
Posted by Gordon McLeod (Member # 33) on 08-16-2000, 02:50 PM:
Check for perf damage to see if the sound head is slightly punching perfs
Also i have had problems with both the linkage to the variac and the brushes in some variacs binding just enough to give problems
A fish scale can be used to measure the amount of pull each platter is exerting on the film
Posted by John Pytlak (Member # 331) on 08-16-2000, 03:17 PM:
SMPTE Recommended Practice RP 106, "Film Tension in 35-mm Motion-Picture Systems Operating Under 0.9 m/s (180 ft/min)" specifies that "Film tension under normal operating conditions shall be 1.7 to 4.4 N (6 to 16 ozf)."Tension that is too low gives a loose wind. Tension that is too high risks perforation wear from the sprocket teeth.
------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Posted by Manny Knowles (Member # 1171) on 03-07-2002, 09:14 PM:
I'm having a loose-wind situation with a Christie AW3 system.There are no elevators with the Christie system...and each platter deck has its own rewind tension arm. And, yet, they are all winding loose.
I calibrated according to the Christie spec's (as I do on all of my Christie platters) and this one just doesn't wrap right.
I have seen two sets of calibration instructions from Christie manuals...the directions from my manual are provided below...
With the feed plate arm at 70, the resistance across pins 12 & 14 is 70KOHM.
With the feed plate arm at maximum, resistance is less than 60KOHM.
Platter speed at 70 = 20rpm
Platter speed at 100 => 25rpm
Platter "creeps" when the feed plate arm is at 20
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And, hey! Let's be careful out there.
~Manny.
Posted by Steven Gorsky (Member # 603) on 03-07-2002, 09:51 PM:
Manny,
Try calibrating your AW3s using Brad's instructions on the Tips page - "Christie AW3 Platter Tweeking". I've not tried this personally, but others here have with great success.Steven Gorsky
Posted by Brad Miller (Member # 2) on 03-07-2002, 11:18 PM:
Manny,Your AW3s have "U" shaped legs, not "V" shaped legs, don't they?
Posted by Manny Knowles (Member # 1171) on 03-08-2002, 01:18 AM:
I just saw those tips and I'll try that method tomorrow (Friday).Actually, Brad...the legs on these units are V-shaped.
I'm curious about the difference...did they change on the inside, too?
...And, while we're at it, how do I replace the lower nutsert on the slide bar? I have a couple where they've gone missing or snapped loose due to overtightening (there's been a LOT of overtightening here). The problem is access to the interior of the tree...am I going to have to break the rivets on that panel near the bottom motor?
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And, hey! Let's be careful out there.
~Manny.
Posted by Brad Miller (Member # 2) on 03-08-2002, 03:51 AM:
Interesting. I asked because I've never seen the older platters with the U shaped legs takeup tight to any degree, but have not had a problem with any of the later production units with the V legs. You can remove the entire takeup arm assembly with 4 bolts on the side of each arm and install a new spring from Christie, or play with some springs from your local hardware store. Just remember there is such a thing as "too tight". Don't go overboard. Just tight enough to take up smoothly and snug. 
Posted by Manny Knowles (Member # 1171) on 03-21-2002, 06:38 PM:
Guess What?In this booth, two of the Christie Platters have U shaped legs and this was indeed one of them.
Brad: Can I still tinker with the rewind spring like you were suggesting when I thought this was a unit with V legs?
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And, hey! Let's be careful out there.
~Manny.
Posted by Kara J. McVay (Member # 1285) on 12-07-2002, 09:15 AM:
I thought this would be a good place for my question. I have a very loose print of LOTR (I am showing it to my local university, not the public), anyway reels 1-4 all have sprocket perfs on the sound side. When it came to me reels 1-4 were all stuck together because of being shipped loose. I had over 200ft of film on the floor trying to fix this mess, it was just all over the film cans, very dirty:( Needless to say I don't want to ship it back this way. Does anyone know a way to make it wrap tighter when I ship it back? It is still very loose on my platter. The print of "Treasure Planet" is just fine on the same platter. Any help would be great. Thanks in advance,
Posted by Shaun Flichel (Member # 1435) on 12-07-2002, 09:22 AM:
I also have a question reguarding take-up tightness. We are lucky to have to use those stupid switcheroos, it would be alot better if the print was alittle tighter when it comes to moving prints. I just thought of the idea on move nights, maybe to hang some sort of weight off the yo-yo, i believe this would work, but I dont know how many ounces would be ok for this, I guess I will play when I go in tonight.
Shaun
Posted by Shaun Flichel (Member # 1435) on 12-07-2002, 09:24 AM:
BTW Kara, just break it down as usual, and if your still worried about it flying all over the cans, tape the end with a long piece of masking tape to ensure it stays put.
Shaun
Posted by Darren Crimmins (Member # 1116) on 12-07-2002, 12:29 PM:
If you are only concerned with shipping out the reels that are tight enough, you could do a normal breakdown, then transfer the reels to your rewind bench. You can then set the tension however you wish with the adjustment on the counterweight (probably not the right term) to have the reels properly tightened. I know you can do that on a Kelmar rewind bench, but not sure about others.
Posted by John Pytlak (Member # 331) on 12-07-2002, 02:01 PM:
Taking off onto reels on your makeup table, then rewinding is your best option. Be careful not to cinch the loosely wound roll, trapping abrasive dirt between the slipping convolutions of film, causing cinch marks.
For winding onto cores, I much prefer rewinds that use "pressure wind" or a buildup roller rather than having to tension the film for a tight wind.
Posted by Andrew Duggan (Member # 1302) on 12-08-2002, 03:02 AM:
I had the same problem with my Christie AW3s at my old theater. These were also the V-legged ones. The winds weren't so loose that it caused any major problems, but this was in a mall that had two theaters, an 18plex that ran new prints and a 12plex that showed the 2nd run prints. So every Thursday, we had to move two or three of these spongey prints across an entire mall. I don't reccomend this. ![[Roll Eyes]](rolleyes.gif)
I quit just about the same time that one of the other projectionists dropped "A Walk To Remember" in mid-mall, right in front of Best Buy. I would pay good money to get the 5 hours of security video of him sitting on the floor, in the middle of a mall at 4am, trying to get the print back together again...
Posted by System Notices (Member # 2357) on 10-15-2004, 09:39 AM:
It has been 677 days since the last post.
Posted by Phil Blake (Member # 2012) on 10-15-2004, 09:39 AM:
Greetings all , well I am looking for some answers for a loose print problem. One I have not experienced before.
Yesterday we built the print of "Collateral" it was quite loose on the plate more than normal.
After it was run today I expected it to be tight , it was still quite loose . We are running 12 different films on all platter plates and they are all winding tight except for this one print of Collateral. It has been run on 2 platteres and on different plates and the result is the same. The platters are C/meccanicas . Any ideas ?
Posted by Bill Langfield (Member # 818) on 10-15-2004, 10:10 AM:
Hey, Phil.
Need more info.
Was the print NEW?
Was the print from Atlab or some dodgy place O/S?
What is the film stock code?
(just asking that incase our ones start shredding, been happening a lot lately)
Did the print come from a ('Red Carpet' preview) Hoyts cinema?
(that could be your problem RIGHT there)
Have you tried running sound track up?
My guess is that it has slight perf damage. I'd feel the the perfs as it runs to determine.
Bill.
Posted by Phil Blake (Member # 2012) on 10-17-2004, 02:24 AM:
thanks Bill,
I know the print was used, The code # 238 3 617 436 103
Kodak 29.2.004p
Print copy # 126
Phil
Posted by Leo Enticknap (Member # 534) on 10-17-2004, 06:22 AM:
Slight perf stretching would be my first guess too, followed by a manufacturing fault with the antistatic layer. That would only be likely to affect one reel rather than the whole print, though. Is it especially loose at one place in the roll or evenly loose throughout?
Posted by John Pytlak (Member # 331) on 10-17-2004, 03:15 PM: