This is topic Ballantyne take-up speed problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Scott Balko (Member # 438) on 05-13-2001, 10:13 PM:
I just tried running film for the first time through my Ballantyne (pro 35 projector, model 7 sound head, V.I.P. pedestal) and the take-up wasn't going fast enough. Seems that the drive ratio is set up for reels with the 5" hub. I have one reel with a 5 inch hub and about 75 with what I think is a four inch hub. I think that says it all. Is there a larger drive pulley or a smaller driven pulley for the vip take-up that will speed it up so I can use the reels I have?
Posted by Randy Stankey (Member # 64) on 05-13-2001, 10:21 PM:
Have you checked for slippage in the drive "linkage"?
The belts could be slipping or the friction clutch could be too loose and not turning the reel fast enough, even though the machine "wants" to turn the reel at the right speed.I have had this problem before and I have had the reverse problem where the clutch was all caked up and wasn't slipping like it was supposed to, thereby pulling the film too hard. (On a Norelco AAII that had been sitting idle for years.)
Posted by Ken Layton (Member # 133) on 05-13-2001, 11:19 PM:
Do you have the magnetic clutch takeup motor or just a regular reel arm mounted in the VIP pedestal?
Posted by Paul G. Thompson (Member # 655) on 05-13-2001, 11:30 PM:
Try Randy's suggestions.
Posted by Mark Gulbrandsen (Member # 72) on 05-14-2001, 09:58 AM:
Scott,
The best thing here is to take the take-up pulley off and find a local machine shop and have them make it about 15 to 20% smaller in diameter. That should give you enough increase in rpm at the take -up to work with the 4" reels. The Balcos were designed for running large diameter reels with large hubs. Thats why its dragging its ass a bit.
Mark @ GTS
Posted by Scott Balko (Member # 438) on 05-15-2001, 07:10 PM:
I know that I don't have belt slippage. The V.I.P drive is a v-belt and it is tight enough. I don't have the problem when the reel is full or when it hits about that magic 5 inch hub size with film. Thanks for your input, but the only other answer I could come up with besides what Mark suggested is to put a smaller pulley on the take-up if it was available. Thanks again for the suggestions. 
Posted by Randy Stankey (Member # 64) on 05-15-2001, 11:58 PM:
Some stupid questions...Are the two pulleys the same size or different? Is it possible to switch them around?
Hypothetically speaking, if a 3 inch drive pulley, turning at 100 RPM is connected to a 6 inch driven pulley the "output" would be 50 RPM. Switching the two around would result in a 200 RPM output.
Posted by Gordon McLeod (Member # 33) on 05-18-2001, 11:37 AM:
The VIP base clutch was designed for a large hub only. I always had them turned down or put a torquue motor in them
Posted by Scott Balko (Member # 438) on 05-19-2001, 10:35 PM:
Well Randy, to answer your question, the pulley sizes are very different. The drive pulley is about an inch and a half, and the driven is about 6 or seven inches. They are also very different as far as mounting goes. As of right now, I'm getting the driven pulley turned down to speed it up. I have a talented machinist in my shop that should be able to keep the angles correct.It seems a little stupid to build a drive system that has a nominal reel size of 24-26 inches, then build it to turn so slow that it needs the larger hub. Just an opinion.
Posted by Randy Stankey (Member # 64) on 05-19-2001, 10:59 PM:
You'd think that they would have considered all this when they designed the things. Maybe even designed the thing with "Christmas Tree" pulleys so you could change the speed of the takeup reel.I dunno'. Maybe I think too much.
Posted by Jerry Chase (Member # 660) on 05-20-2001, 12:54 AM:
I wonder if the design was intentional to prevent running on shipping reels. Also, I used to have problems if a film had proud edges and a nearly full 5K foot reel. The torque at the outer edge of the reels wasn't enough to make the film sit down, and I remember having overflowing reels. I imagine the problem would have been worse if the pulley were smaller. The good thing was that changeover slap didn't start as quickly as on some other machines.
Posted by Gordon McLeod (Member # 33) on 05-20-2001, 09:50 AM:
The VIP base was designed for use with I believe up to a 30" reel.
As such they based it on the larger core diametre of large reels. Not the smaller shipping reel size since that was not what it was designed for