Film ‘snag’ on take up (Westrex Tower)

[Steve Pike]

Hi,

Something peculiar seems to be happening recently when showing a feature using my Westrex tower (projector is a Kinoton FP-25D).

On the take-up reel, the film seems to ‘snag’ somehow, it seems to slows down the take up reel slightly and then it the reel catches back up to speed - creating a short ‘snap’ sound (but not a film snap/break). It has also, previously, created a small lump/buildup of film as it gets collected on the take up spool - which then gets compressed down as more film builds up - which damages the film.

I’ve set the tension at 130 for take up, any less and the take up speed isn’t enough for startup and film is leaving the projector faster than it is being taken up!

I am using the larger Robert Rigby capacity tower spools (with the smaller core) to accommodate films up to 2hr45m (ish).

This issue seems to only occur when using the larger reel capacity and with a print that’s polyester. Not sure if the two are connected to the issue, or if it’s coincidental, but welcome anyone’s thoughts! Had a thought that maybe it’s a static issue - I have no film cleaner or anti-static brushes as part of the film path.

I’ve replaced the take up motor (had 2 spare), but the issue is still present.

I’ve attached a short video showing it in action. I’m loathed to run any film through until I know what’s happening (especially the film you can hear the soundtrack to … gold star for anyone who can name it!)

YouTube Vid (as a short for some reason):

[Sam Chavez]

I would sure check the take up reel shaft with no gearbox/motor/belt connected to it for some binding or friction. There should be some end play in the shaft in it and should of course should be perfectly straight. It may have been damaged at some point in the past. Just a thought.

[Brad Miller]

It really looks like there is one spot in your takeup reel where the flange is bent and it is grabbing the film (because the two sides are closer than 35mm apart).

Of course it also looks like the back flange of the reel is just barely touching that box.

Either of the above would cause the film to slack slightly and then bounce back to normal tension.

If you could move the box and verify by running a core around the entire outer perimeter of the reel to ensure you don't have a spot too close together, I would be curious if that resolved the issue. If not, could you shoot another video in normal horizontal mode and upload as a normal video on youtube? These vertical videos don't have any sort of playback controls, so we can't repeat the same few seconds here or there to analyze it.

[Phillip Grace]

I'm thinking along the same lines as Sam.
Does this machine have a friction clutch? It might have worn or need a clean up, and as Sam mentioned, is it possible the shaft bearings are binding?
Also, I'm wondering if the film is slipping around the hub of the spool as it takes up near the beginning of the show. ie. the film is tending to stick to itself rather than the hub in the early part of the run, leaving the wind a bit loose and free to adjust itself at random. The stickiness effect might be due to static issues, raised perforations, or oily film not behaving as required. Maybe try sticky-taping the head of the film onto the hub when threading - (Yes. I know it is an evil thing to do!) - and make sure the first couple of wraps are quite firm before starting.

[Randy Stankey]

The first thing I would check is to be sure your reel flanges are true. If the flanges are not true you might experience snagging which will cause an uneven wind. Also check the center hole of your reel. If it is wallowed, you might get the same effect as the reel wobbles on its shaft. You can test both of these by using another reel which you know to be good. If the problem goes away, you have a bad reel.

Once the reel has been eliminated as the source of the problem, look at the shaft. Is it straight and true? Does it turn without binding or catching? Is there any other damage?

After that, work your way up the chain to be sure everything works the way it should: Bearings, pulleys, belts, shafts, etc. Are they all running straight and true with no binding?

Dumb question: Was the reel inserted onto the shaft properly so that it fully engaged the drive key? I've had Homer Simpson "Doh!" moments like that!

[Steve Pike]

Hey all, Thanks for all the suggestions

an update this morning - have moved the tower closer to the last roller in the chain which should eliminate any bounce , removed the top cardboard box and used the smaller hub reel. Also adjusted the take up tension to 120 from 130.

Ran the film this morning and seems to be ok today.

going to keep tabs on it and see if it repeats the next time I test it.

[Pete Naples]

Many years with Westrex towers, I learned a lot.

It's better to use the large centred spools in the take-up position. Better still, the floating-hub type.

130 on the take-up is fine for running, but maight well cause snatch on starting. Feel free to increase the setting for starting then reduce once the projector is at speed.

Warped spools and any un-intentional mechanical contact with the spool will cause issues.

Bext place for a tower is on axis, behind the projector.

Somewhere I have the manual. I could have sworn I scanned it for the warehouse here on film-tech