Film-Tech Forum ARCHIVE: Frankensteins Platter Lives!

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Posted by Andrew Bangs (Member # 4938) on 12-28-2008, 12:40 AM:

Well over the last two days I have had to do some serious jerry rigging to get our projectionist away from baby sitting a latter system and all I can say is it comes down to team work and working with what you got.

Dec 25th while I was watching Benjamin Button our projectionist runs into the theatre to get me. apparently the take up on one of our platters is running away and stretching/crunching film. When I get up their one kid is acting like a break putting enough back pressure on the platter to keep it from screwing up the print. I played with the speed controls with no effect. Then the platter stopped moving so we had to spin it, then it acted normal, then it took off again. The thing just went nuts. After trying to reset the platter again with no luck I Grabbed the MUT plugged it in and took control of the pay out speed with that. this worked but it meant constant supervision to keep the speed just right. then next day I go back to our old theatre to grab our only remaining Strong Platter system in hopes of using it as a replacement till I can figure out what the hell is going on. I get it to the theatre set up ready to run and for the previews all is good. Then as I say goodbye for the afternoon I hear this gut wrenching grind of film. the bring had speed wrapped and snapped the film. We rush in cut out the damage (only about 12 frames) splice thread and get it running again. but 5 min later the same thing starts to happen again. with a quick lip of the Brain arm back and forth it goes back to working for two revolutions then tries to wrap again. so as I am sitting their thinking what the hell am I going to do. it hits me the pay out on the old platter was god and the take up on the strong is good soooo... now we are running the film from one platter system through the projector to another platter system. Then in between shows we move the print back and start the whole show over again. God What a mess!

Just incase you are wondering the original platter that failed was a Horizon platter system. I have tried replacing the circuit card for take up opperations. but the new card acted the same as the old. I have yet to try and replace the optical sensor in the base unit but I don't have any as of yet that I know are good replacements. I did find one guide wheel that was loose on the tension pully system so that may have lead to our problem as the contact switches may not have been getting hit properly. this is why the platter did not stop when it hit it's top mark and crunched/stretched the film. the brain of our Strong just seems like the micro switch just does not want to turn off sometimes as the arm moves away. I did try bending the contact rod back to give the switch more room but it will switch off some times before the arm contacts the defending post and then it wont at all.

Does this sound like a bad switch or just one that needs to be cleaned? If it just needs to be cleaned then what can someone suggest I use to clean it and how do you clean it? I am fairly good at working with electronics and If I screw it up well then I am no worse off so I am ready to give this a shot. Perhaps their is an online guide someone can reference me to.

Posted by Tim Reed (Member # 137) on 12-28-2008, 08:01 AM:

You don't say what flavor of Strong platter you have, but you should be able to find whatever you need here:

Design and Mfg. Platter bulletins and manuals.

When you say the feedout is wrapping, I take that to mean it's feeding out too much film instead of not enough? If the microswitch itself isn't releasing (although the feedout arm returns), the switch needs to be replaced. If the arm doesn't return, either the platter isn't level or there is some kind of problem with the feedout plate itself (bad bearing, assembled incorrectly, bent arm that's dragging).

Posted by Jim Cassedy (Member # 4115) on 12-28-2008, 10:00 AM:

Must be something about Ben Button & Christmas day.
I guess "Murphy" doesn't take Christmas off!

I had a xenon lamp start fluctuating during a packed evening show.

The ammeter would suddenly dip down to about 60A from from it's normal 90.

The rectifier (a stand-alone Christie) had been rebuilt less than a year ago, and the bulb is only a little over a month old.

Ironically, the 'quality control" tech sent by Paramount Pictures had been there earlier in the day to make sure our projection system was up to specs & commented that we had "great light" on our screen.

(you're welcome! [thumbsup]

)

It started near the end of the film. Nobody complained. When I asked one of my friends who was at that show if it was distracting she said she thought it was part of the movie. [Roll Eyes]

I couldn't find any obvious problem. There were no loose connections or arcing anwhere on the HV side of the rectifier.

Between shows, I shut the rectifer down and gave the big current adjusting knob on the front a number of turns through its' range to wipe the contacts clean.

That seems to have done the trick.
The ammeter and lamp were rock-steady all day Saturday.

My theater is located within sight of San Francisco Bay, and the Ocean is also close by. I'm always fighting the effects of "salt air", on my systems both at home and work.

Posted by Dave Macaulay (Member # 813) on 12-28-2008, 12:37 PM:

The Strong platter microswitch payout can't do much anything except turn ON and OFF. The adjustment for the microswitch action is not by bending the microswitch lever (it should be straight): you remove the two nuts holding the switch cover on then loosen the two nuts below the cover, finally moving the entire switch until it's in the right spot and retightening. I try to centre the switching point between the arm's extremes of motion.
If the switch sticks closed and there's no mechanical problem with the arm then you need a new microswitch. They are not cleanable or repairable and they have a limited lifetime.
Mechanically the arm must move very freely, and not touch the payout plate. A common mechanical fault is when the control arm bends upward after someone grabs it and heaves up to unplug the payout. The arm roller can then ride up over the base of the plate roller and get stuck there so you have that overspeed wrap. The rollers should just bang together, not get jammed up with each other. Careful bending of the arm will make this right.

Posted by Demetris Thoupis (Member # 833) on 12-28-2008, 01:36 PM:

Sorry to say but change the Horizon to a decent platter system like Kinoton or Christie
Demetris

Posted by Steve Guttag (Member # 268) on 12-28-2008, 01:39 PM:

Jim,

Another place to check is the contactor...if it has a contact going bad, you'll get intermittent contact on one leg and get the symptom you describe.

Steve

Posted by Tim Reed (Member # 137) on 12-28-2008, 03:50 PM:

quote: Dave Macaulay
I try to centre the switching point between the arm's extremes of motion.

FWIW, the original factory recommendation is 3/8" from the full left position of the feedout arm. If you figure full off as "0" and full on as "100", the microswitch should close at about "80".

Posted by Monte L Fullmer (Member # 2797) on 12-28-2008, 06:31 PM:

When I saw the header "Frankenstein" - I knew it was a STRONG platter... [Big Grin]

(Dang, how I hate microswith brains...and this is a warhorse topic at times)

I just hang the brain on its end to where the feed arm just before the 6 o'clock position and that is where I adjust the switch to click.

If you got a Grainger's around there, get 6X284 OMRON snap action microswitches and save a few pennies... Just make sure that you take out the spring to make the switch more sensitive.

(But, if you want to eliminate this problem, convert to phase control units for the brain)

Also, there is the same snap action microswitch down in the variac control box that control the entire platter unit that also loves to either get out of adjustment, or the contacts inside the switch will arc themselves together to keep the platter unit on all the time....

-Monte

Posted by Andrew Bangs (Member # 4938) on 12-29-2008, 12:59 AM:

Thanks for all the tips. I am pretty sure the micro switch has gon bad but I will check the contactors. As far as the Horizon Platters the owner of our theatre is sending off an e-mail to the company to tell them what he thinks of their stuff and I hope to try and get us a tech as this is the third platter system to go down on us in the last 6 months.

Frankly the strongs have been saving us as replacements. A simple 12 dollar part and I can get this last one working on it's own is allot better than having to wait for a tech from China!

Posted by Joe Redifer (Member # 3) on 12-29-2008, 01:14 AM:

Why is your tech in China? I demand to know the answer to this. I think the tech should be closer to the theater, like in England or something. [Smile]

Posted by Tony Bandiera Jr (Member # 2365) on 12-29-2008, 02:22 PM:

Andrew, go over to the Equipment for Sale forum, there are (7) Aw3's for sale at a great price so you can end at least part of this nonsense. [Smile]

Posted by Demetris Thoupis (Member # 833) on 12-29-2008, 07:59 PM:

I have had experience with Christie, Cinemeccanica and Kinoton Platters. Christie Platters run like a charm BUT do not have any safety in regards to brain wraps e.t.c. Kinoton platters (the E series) are very reliable, have sensors for brain wraps and also for film breaks. They use advanced technology and I find them far better than the Christie ones. Cinemeccanica I believe have the best safety features in regards to brain wraps and film breaks. If I was to choose for installation wise, I would go with the Kinoton platters for the fact that during both makeup and breakdown, the platter motors are engaged making both breakdown and makeup very easy and also have correct safety features.
Demetris

Posted by Chris Slycord (Member # 4239) on 12-30-2008, 05:18 PM:

quote: Demetris Thoupis
Christie Platters run like a charm BUT do not have any safety in regards to brain wraps e.t.c.

Couldn't you buy a wrap detector that someone else makes and wire it to control your platter?

Posted by Monte L Fullmer (Member # 2797) on 12-30-2008, 05:32 PM:

I've seen STRONG's wrap detectors mounted on AW3 towers...and Christie does have it's own wrap detector...

Posted by Scott Norwood (Member # 30) on 12-30-2008, 06:07 PM:

Are brainwraps _still_ a major problem? Where and why? My one and only brainwrap was the result of a botched trailer change (my fault). Admittedly, I didn't start working with platters until after Kodak solved most of the static issues with polyester film (2000-2001ish). Maybe I've just been lucky?

This is mostly with Christie AW-3s (my favorite), though I have also run SPECO LP-270s, Super Platters, Xetron platters, and maybe others.

Posted by Monte L Fullmer (Member # 2797) on 12-30-2008, 06:57 PM:

The static issue has long been settled with Kodak's new stock.

Brain wrapping is mainly due to operator error, or equipment failure.

..most of which, I've seen, is with those damnable STRONG microswitch brains where the microswitch will fail without any warning - even if new switches were replaced within a few months.

Also with the STRONG brains is that-before an operator laces through the payout arm, they manage to get a loop of film wrapped around one of the plate's outer circumference rollers and not catch this on startup. This keeps the payout arm open and you can get a good 3 inch "beehive" backwrap around the brain.

Another operator error is on the older A-3 units that have the rotary control switch and the operator forgets to put the feed platter selector on 'Payout' and will leave the selector on 'Rewind' causing the platter to spin at a constant rate as the feed platter and an eventual backwrap is created.

Other wrap issues that comes with STRONG platters is when the brushes in the motor have reached their service limit causing the motor to slow down (or even stop) on payout and then a wrap is created on this event.

Christies - it's practically all motor card or sensor adjustment issues why these units will wrap from time to time.. AW-2's .. module or even grumpy feed finger springs giving fits once in a while ..or even the Bodine motor brushes - being that these units used reduction transmissions to run that drive tire.

SPECO's were that magnetic reed switch under the brain in the platter arm that'll give fits once in a while, but that can be easily adjusted out with the adjustment of the magnet above it which is attached to the brain itself.

-Monte

Posted by Gordon McLeod (Member # 33) on 12-30-2008, 07:13 PM:

Post the manual for the horizon platter here so that maybe we can figure out the problem
Years ago we worked on a chineese platter and the failure problem was the servo pot which we replaced with a NTE one and never haad another issue

Posted by Andrew Bangs (Member # 4938) on 12-31-2008, 12:30 AM:

I'll Try and get that for you guys. Just a quick question though. When I get it in my computer as a PDF where do I go to upload it to this site?

Posted by Monte L Fullmer (Member # 2797) on 12-31-2008, 01:04 AM:

If you goto the Horizon site, follow the instructions below on how to do do the URL insertion in this reply box like this example :

1- Go to this page
2- find the link that has the PDF file that you want to send.
3- highlight the link in the address box of this webpage and then right click to COPY
4- come back to this Film-Tech page and open a new reply box.
5- Goto the "URL" tab below
6- In the script box, (you will see the "http:// already in the box. Clear that out then put the cursor in the box then right click to PASTE that URL in this dialog box, then click OK) is where you put the URL of your choice.
7- In the description box, add what description you wish, then click "OK" All the information will be in your reply box. Then you can add anything afterwards in comment.

In your reply box, if you right click the highlighted description, a dialog box will open and you go all the way down to "properties" and open that tab. Then, you'll see the link attached to that highlighted descripton. Like with mine - right click on it and the dialog box will show - http://horizonprojection.com as the properties of this highlighted link.

Good luck - Monte

Posted by Andrew Bangs (Member # 4938) on 01-01-2009, 12:49 AM:

Thank you but unfortunately I am not linking to a web site but trying to upload a PDF off my own computer. Will the same process work or do I upload the PDF file from my computer to Film-tech in some other manner?

Posted by Adam Martin (Member # 641) on 01-01-2009, 12:56 AM:

You can email it to me and I will post it for you. [Smile]

Posted by Andrew Bangs (Member # 4938) on 01-01-2009, 12:25 PM:

Thank you Adam it is on it's way. [thumbsup]

Posted by Adam Martin (Member # 641) on 01-01-2009, 01:25 PM:

Linky linky

Posted by Monte L Fullmer (Member # 2797) on 01-01-2009, 06:01 PM:

Sorry on the misunderstanding, but a question: Wonder how these platters hold up in duration using graphite as their axle lubrication?

Posted by Andrew Bangs (Member # 4938) on 01-02-2009, 12:12 AM:

Well I have never had to grease the buggers if that is what your asking. I have and to go in and clean up some of the residue as the graphite squeezes out but otherwise they still spin fine mind you we have only had them for close to three years now.

Posted by Gordon McLeod (Member # 33) on 01-02-2009, 09:50 AM:

My suspision is that it is the optical sensor based on the manual
have you tried the complete speed set up procedure in the manual and remember that the max and min controls interact
after adjusting check that there is a smooth speed range as the roller is slid up and down
It appears that the "optical fence" which appears to be a wedged shaped plate behind the roller assembly maybe exposed and extranious light might get into to it
regretably the manual is a bit vague on its construction

Posted by Tony Bandiera Jr (Member # 2365) on 01-02-2009, 03:22 PM:

He'd still be better off replacing that junk with the used AW3's in the Equipment for sale thread. [Smile]

I got a headache trying to read that poorly translated manual.

And any equipment that uses most of the first page of the manual crowing about how great it is usually means it isn't. [Big Grin]

Posted by Gordon McLeod (Member # 33) on 01-02-2009, 06:10 PM:

I doubt if it is up to him to replace it

Posted by Andrew Bangs (Member # 4938) on 01-03-2009, 02:50 AM:

Gordon... How right you are...

The first thing I tried when the problem initially occurred was adjusting the speed controls but this had no affect as it seemed that the take up was bypassing the optical sensor somehow. My thought is some crossed connection in the wiring somewhere. Regrettably the maintenance hatch has been open and missing for the last year plus since someone thought they may have to get to the optical sensor in a hurry. The connection on those buggers is notorious for coming loose and when it shifts the take up platter no longer spins. simply "jiggling" the wire or reseating the connection gets it running in no time. One projectionist before me even tried zip tying the little buggers in place but that only put off the inevitable.

Just recently I observed the electronics doing something rather strange. While switching a platter from normal to MUT control one of the wires to the switch popped off. Yes they were soldered on but enough current hit it during the switching process to melt the solder and break the connection. After examining the sensors on a few of our dead Platters not only did I find more evidence of this on some switches but the trace on the backs of some of the Optical sensors had blown away and the previous Projectionist soldered back on his own connection using a bit of wire to gap the prongs. Talk about ghetto... Right now I think we have a bigger power issue to solve as these things are getting too much juice. Or are drawing to much for their own good.

I just don't know... In the mean time I am keeping things together as best I can in hopes one day (soon) they will either get a real tech to come out or just Buy new/used Platters to replace this junk.

Tony, From your mouth to gods Ear!

If you guys think of anything else let me know I appreciate all the help I can get and all that I have gotten. P.S. Thank you Adam for the linky.

Again Cheers!!! [beer]

Posted by Louis Bornwasser (Member # 3063) on 01-03-2009, 09:37 AM:

If the tech has too much travel, it will be just as cheap to replace AND that gives a guaranteed result.

Myself, I would not get involved since repair will end up being "experimental" unless it is completely redesigned. and that costs too much even if performed in the shop. I only deal in guaranteed results. Louis

Posted by Richard Fowler (Member # 893) on 01-03-2009, 02:03 PM:

Richard Hamilton should have the answers.......

Posted by Demetris Thoupis (Member # 833) on 01-03-2009, 02:33 PM:

I also concur on buying the used Christie platters. Try pursuading your manager that is for the good of all of you or otherwise Horizon should really come down and try to get that booth up again in a prime state. It's sad not being able to do anything.
Demetris

Posted by Richard Hamilton (Member # 321) on 01-07-2009, 09:52 AM:

quote: Richard Fowler
Richard Hamilton should have the answers.

Ha....Yes, I do....

The platter timing is my fault, I will explain later, I am in a hurry now.

Rick

Posted by Andrew Bangs (Member # 4938) on 01-09-2009, 12:53 AM:

Please tell me their is something I can do to fix this for the short or long term.

Posted by Richard Hamilton (Member # 321) on 01-09-2009, 11:28 AM:

Andrew,
First check the roller assembly that switches the deck from payout to take-up. Could be the cam is loose and not engaging the microswitch inside the tree. If it is traveling that hard and fast it almost sounds like it is in pay-out mode. When the rollers travel up that high, the take-up should slow almost to a stop, if they hit the switch, the platter should shut off. I doubt if it's that switch because it should only be creeping when it gets high enough to engage that switch.

You said you adjusted the platter during the show, which is fine if it gets you through, but then you need to recheck the timing afterwords. As Gord said, the min and max controls interact.

My advice is to time the decks with no film on it almost according to the manual, just change the low speed part so that it just stops, this way it won't creep when the film is threaded and sitting idle. Do the low, then high, then check the low again, then high again. Then adjust the take-up speed according to manual. Double check everything again.

Make sure that you mark each control plate and that they are designated for each individual deck and stay there. When you are done, run a film(full length) onto it, then time that deck that is now empty. Now run the film through each deck. You may have to fine tune them for pay out. If you do, check it the next time you run it through.

It sounds lengthy, but it's not. Once it's set, just don't let anyone mess with it.

I talked to the owner of Horizon a few weeks ago and he was unaware of any issues at your theater. He was going to ask the owner of your theater. That was before you posted this problem though, so hopefully they can send someone. I also talked to the factory in China and they are interested in resolving any problems. I am going to China in a couple weeks and am planning a trip to Harbin, where the factory is. E-mail me a list of any issues or questions and I will talk to their engineers about them. No promises, as I don't work for them, I'll just be in the area, and I also want to make sure you're up and running.

Rick

Posted by Andrew Bangs (Member # 4938) on 01-09-2009, 02:53 PM:

Thanks Rick for the suggestion and I will try to bang out a list for you. The one thing that I wanted to mention is that when we originally had the problem the Take up rollers did hit the top and did not stop the platter. They also later hit the bottom and did not stop it. which says to me now to check the changer over arm and it's switch. However I will have to investigate this more as one problem I fixed while initially trying to get this thing going was one of the guide wheels was loose on the take up rollers. So the contacting arm for those top and bottom limit switches may have been out of place and not even making contact. I did get the rollers and guide wheel back in alignment and I want to say the problem still existed but I can't swear to it as it was a couple weeks ago now. I will check it again tomorrow and either up date this post or leave another one.

As for the owner of the company both Harbin and Rio I know they just got in touch with each other a day or two ago. So hopefully things are in the works and this will soon all be a distant memory. Keep looking for an up date. And thanks again for all the help!