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Author Topic: Roundthane question Frank Angel Film God Posts: 5305 From: Brooklyn NY USA Registered: Dec 1999 posted 06-05-2003 12:48 PM                        I had something very odd happen in the last two weeks. The rollthane belt on one of my projectors broke. It was a clean break, as if someone had cut it with a knife. OK, thinks me, material stresses out and breaks. But then a week later I am running THE PIANIST and low and behold I walk back into the booth from the rewind room and there is a pile of film on the floor. The rollthan belt on the second machine had snapped also. This, as I said, within a week of the first mishap and the break was as the first, clean as a whistle. What's going on here? The belts are not too tight and they have been running without incident for a dozen years or so. All I can think of is that I used a solvent cleaner on them a few months ago to keep oil off them. Is it possible that a solvent like 1.1.1. Trichlorethan (and forgive me if I am not spelling that correctly -- or rollthane for that matter) can weaken the composition of the plastic? Never had any trouble with the old leather belts. I am thinking of going back to them if this plastic stuff is not reliable -- it's pretty, but of no substance! Perhaps they shouldn't have tried to fix something that was working just fine. Or is the leather belting another PETA issue? How many cows have to die for your to run your projectors? Frank  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 06-05-2003 01:12 PM                     I'm not Steve Guttag, but in my opinion if you've got 12 years out of those belts, they are due for changing anyway. I've never seen a Roundthane belt last that long. I don't know if trichlourethane would damage them or not, but from the sounds of it the chemical does. Steve will know. I understand the clear belts have a better life than the yellow belts. I've never done any personal testing though. Why do you not have some form of failsafe? Even in a manual changeover booth, in this day and age it doesn't make sense not to have one. Ya gotta go crap sometime and you want some kind of protection before the takeup craps on you!  |  IP: Logged Christopher Seo Jedi Master Film Handler Posts: 530 From: Los Angeles, CA Registered: Jun 99 posted 06-05-2003 01:49 PM                     I didn't imagine those plastic belts could last 12 years, either! I'm trying to set up a schedule for changing out the rounthane periodically, so any input as to how often you changeover projectionists replace your takeup belts is appreciated. BTW, Frank, where did the break occur? The only spot I could think of to break so cleanly would be the point where the barb digs into the rounthane.  |  IP: Logged Jonathan M. Crist Jedi Master Film Handler Posts: 531 From: Hershey, PA, USA Registered: Apr 2000 posted 06-05-2003 02:22 PM                     I have had the same roundthane on my two projectors (6,000 foot automated changeovers) for 15 years. Never have had a problem. They look and perform as good as when they first installed 15 years ago. Before that I used to used standard auto "v" belts because the leather just would not take the rack from the stress and strain of the 6,000 foot reels.  |  IP: Logged Jeff Taylor Jedi Master Film Handler Posts: 601 From: Chatham, NJ/East Hampton, NY Registered: Apr 2000 posted 06-05-2003 02:24 PM                     Ditto Brad's comment...I've had excellent results with the clear belts.  |  IP: Logged Dick Prather Master Film Handler Posts: 259 From: Portland, OR, USA Registered: Feb 2002 posted 06-05-2003 03:21 PM                     Frank, I have also had problems as you describe using the yellow belts (Roundthane). Some places lasted only a couple of years and others several. When they broke it was like old wire insulation does when you bend it. The belt seemed to reach a time when it was just shot and would break everytime you fixed it. The blue belts (O-Thane) were worse. Not sure if I have the names reversed. I have had good results with the clear belts form Wolk. It uses the same barb to fasten it. Some of those are over 5 years and going strong on 6000' reels. They sell it by the foot with barbs extra. The best is a V belt for long life which you should be able to get from any good auto store. Most take up's were set up to run them and Simplex even had part numbers for them. I am sorry I don't remember the sizes. 3/8" leather belt works well also. It was used from the beginning. Getting the staple in right helped. They actuality made a special set of pliers to cut, punch the hole, and set the staple for leather belts. Someone probably still has one somewhere in the NY area. That makes leather real easy to work with  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 06-05-2003 03:54 PM                        I, too, would be interested in knowing if there is a recommended interval at which roundthane belts should be changed. I've never had one break on a projector, but I've had one that constantly broke on an older Kelmar rewind bench. I replaced it and it's now fine. Do people change these things on a regular basis, or do they just wait until film starts getting dumped on the floor (hopefully not into a puddle of oil)? Roundthane seems to be fairly expensive, so it's not something that one would normally want to change out unless it's necessary. Yes, we'd all love to get electronic-drive Kinotons where the takeups are driven with torque motors, but that isn't going to happen anytime soon. And, Brad, I've never seen a manual booth that had failsafes anywhere. I guess that the assumption is that the presence of an operator in the room should be sufficient.  |  IP: Logged Sam Hunter Jedi Master Film Handler Posts: 779 From: West Monroe, LA, USA Registered: Jan 2002 posted 06-05-2003 04:08 PM                     I am using a leather belt that I picked up at the singer sewing machine shop (used in treadle machines) and it seems to work pretty darn good. I am not sure of the size though, I would say it isn't quite 1/4". On the other hand I haven't ran a whole lot of stuff yet so maybe I need to be carefull, but Hey, I got a failsafe  |  IP: Logged Dan Lyons Jedi Master Film Handler Posts: 698 From: Seal Beach, CA Registered: Sep 2002 posted 06-05-2003 06:09 PM                     12 years?!?! Soft plastics and rubbers tend to get less pliable and brittle over time. It's not very surprising that it would snap eventually. Danny  |  IP: Logged Gordon Bachlund Jedi Master Film Handler Posts: 696 From: Monrovia, CA, USA Registered: Aug 1999 posted 06-05-2003 06:26 PM                        Frank, I really believe you can't beat leather belting for durability. While plastic belting can be solvent welded, good old leather with a mechanical joint lasts and lasts, and oil leaking on it just makes it last longer.  |  IP: Logged Steve Kraus Film God Posts: 4094 From: Chicago, IL, USA Registered: May 2000 posted 06-05-2003 06:34 PM                    Failsafes would require something to hook them up to to kill the motor, close the C/O, and cue the dimmer. I think they would kill shows that didn't need to be killed. Takeup failures are rare enough that they aren't needed. I almost always take up on shipping reels (given that I'm usually only screening a film once) and even as bad as they sometimes are and sometimes they are only holding together because of the shaft clip (I'll use a proper split reel if a shipper is too broken) I can think of only once in recent years that I had a takeup failure due to the reel and once when a belt broke and in both cases manual intervention kept the show going while a failsafe would have killed it.  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 06-05-2003 08:26 PM                     I've seen varying opinions as to whether you should heat the roundthane around the barb after installing the barb. What are FT opinions? --jhawk  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 06-06-2003 11:16 AM                       Frank, that's normal failure for those, as several folks have mentioned. They'd break very close to the joiner - straight across. Then, again, maybe you're having union trouble?  |  IP: Logged Robert Golding Film Handler Posts: 65 From: Sutter, CA, USA Registered: Jan 2001 posted 06-06-2003 04:00 PM                     I've had troubles before, so I took the time to measure the length of my belts. I bought your standard one piece v-belt and installed them. I've never had a problem since. It's not as easy as the other types but it will sure take care of your problem.  |  IP: Logged Bill Enos Film God Posts: 2081 From: Richmond, Virginia, USA Registered: Apr 2000 posted 06-06-2003 11:58 PM                     I usually get 10 or so years from roundthane. We join them with the aluminum barbed bullet shaped connectors. After about 5 years check them monthly & replace when cracks appear near the join. Connectors pull out of leather and it stretches on 6000 ft. reels, costs a lot more too, if you can find it.  |  IP: Logged

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