8mm Forum: Slipping belt or cork cause of slow down on an Elf?

This is topic Slipping belt or cork cause of slow down on an Elf? in forum 16mm Forum at 8mm Forum.

To visit this topic, use this URL:
https://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=5;t=001840

Posted by Can Sanalan (Member # 5988) on July 17, 2018, 04:31 PM:

Hi

Just wanted to ask what would be the most likely cause to slow down a film half way through the reel on an Elf projector?
Would it be a slipping belt or the cork on the take up arm?

I’ve run 400ft reels fine, no problem but when I watch an 800ft or 1600ft reel and it reaches around 500ft the film slows down to about two thirds of the normal speed I’d say.
The belts were replaced recently, bought them off eBay.
I haven’t touched the cork and it looked fine to me when I was cleaning the machine. But I’m wondering as the weight builds up on the takeup arm the belt might be slipping.

I just wondered if anyone else came across this problem and which cause was most likely.

If it’s the cork, where can I get a replacement for it?

Thank you guys,
Can

[ July 18, 2018, 03:47 AM: Message edited by: Can Sanalan ]

Posted by Nantawat Kittiwarakul (Member # 6050) on July 17, 2018, 09:29 PM:

That massive speed drop means some abnormal load somewhere within the drive train. That means anything from the motor itself,the drive belt,etc...to the reel spindle.

For now try this...
At the very beginning - try blocking the reel rotation,does it suddenly slow down?
And after half the reel (when it starts to slow down) try manually turning the reel by hand,does that help speeding things up?

AFAIK you might need some lubricant on the cork surface in order to make it "slip" properly,otherwise it would stick&cause havoc like this.

Posted by Maurice Leakey (Member # 916) on July 18, 2018, 05:54 AM:

The cork liner (washer) should provide the necessary friction, however, if the cork is very dry it will not give sufficient friction and the film will wind too loosely.
The cork liner may need some lubrication, although it should not be applied too liberally.
This Forum has downloads of Elf (Eiki) service manuals. You may care to take a look.
http://www.film-tech.com/warehouse/index.php?category=2#16mm Projectors

Posted by Terry Sills (Member # 3309) on July 18, 2018, 06:15 AM:

I can't see how the take-up arm not working correctly would affect the speed of film projection. That doesn't make sense. There must be some other reason.

Posted by Rob Koeling (Member # 35) on July 18, 2018, 06:40 AM:

Don't mean to highjack the threat, but my SSL sometimes slows down while rewinding. Could that possibly be caused by lack of lubrication on the cork? If so, what to use to lubricate it?

- Rob

Posted by Maurice Leakey (Member # 916) on July 18, 2018, 08:35 AM:

Have I read the posting correctly?
Does the whole projector mechanism slow down towards the end of a film, or is it only the take-up problem?

Posted by Can Sanalan (Member # 5988) on July 18, 2018, 05:57 PM:

Maybe I’ve got it wrong. If it was a take up arm issue the film being thread through would still be at normal speed and there would be film piling up on the floor at the rear as it’s not being taken up which, in my case isn’t happening.
I set up the projector again and ran a 1600ft film through,
Again after around 15mins of playing the film the projector slowed down again. It slows down to a point where the image starts to flutter ever so slightly.
What I did notice this time was the inching knob was slowing down, stopping, starting to turn a bit, stopping, turning etc.
This leads me to think it must be something between the motor and the camtank and it could be the belt between the two. It could be slipping.
The motor is running perfectly fine. If that is the case then why after 15 or so minutes does the projector slow down at that point and not near the start of the film? Hmm. Could it be the motor belt? Would be warming up and it slips I don’t know.:/

Posted by Nantawat Kittiwarakul (Member # 6050) on July 18, 2018, 08:11 PM:

If the takeup is too loose it would cause film pileup on the floor mid-run.
But for this case the takeup is possibly TOO TIGHT,causing the (already loose) motor drive belt to slip and stall the whole projector.
That's why I suggest to try locking the takeup reel at the beginning to see if that gives the same effect. [Wink]

Posted by Maurice Leakey (Member # 916) on July 19, 2018, 02:14 AM:

I think Nantawat is on the right track.
1) Tight take-up.
2) Loose drive belt.
What model Elf are we talking about?

Posted by Can Sanalan (Member # 5988) on July 19, 2018, 06:56 AM:

I see. Didn't occur to me that the take up could be tight. If the belt is tight how could I loosen it?
I'll also swap it with the feed arm belt and see if that does anything.

I'll have a look tonight and see what I can see when the covers are off.

It's an Elf ST/M.

I have another model but I prefer to use this one for quick viewings as the speaker is attached to the unit. Just more convenient for me.

Posted by Maurice Leakey (Member # 916) on July 19, 2018, 08:33 AM:

There is a nitrile take-up belt within the arm but this is unlikely to be any problem. If it is the take-up it's probably that the felt washer is too dry.
The loose belt to which I refer is the drive belt from the motor.
I suggest you go to the site which I indicated above and you can download the service manual for the ST/M series Elf (Eiki) projector. You may gain some useful information on your projector's servicing.
This model is now quite old, perhaps it needs a good service and lubrication.

Posted by Barry Fritz (Member # 1865) on July 19, 2018, 08:51 PM:

It is a motor and/or drive belt problem. Sprockets and claw move the film through the projector. The take up does not pull the film through, it simply reels in the film that has been moved through via the sprockets and claw.

Posted by Terry Sills (Member # 3309) on July 20, 2018, 01:46 AM:

That's true Barry, but I can see that if the take up is too tight ( i.e. The clutch system is not working as it should ) then as the take up reel gets heavier as the reel loads, then the take up will get tighter and consequently put more load on the motor. Maybe to the point where it causes the drive belt to slip. But I would have thought that the over tightness of the take up would be quite obvious and could be determined by simply putting a finger against the film as it passed onto the take up reel, or against the reel itself to slow it down. The take up should not normally be so tight that it could easily be slowed by doing this. Does that make sense?

Posted by frank arnstein (Member # 330) on July 20, 2018, 07:50 AM:

The same thing happened to me this week while testing out an Eiki NT1 projector that I had bought on ebay.

After projecting very well for about half of a 400' reel, it began slowing down for no apparent reason and nothing I tried could fix it.

The cause turned out to be a faulty motor start capacitor. I peeled back the rubber boot and could see that it had started leaking wax and internal pressure had forced the sealing washer to lift allowing wax to leak out.

A modern electronic version was easy to find on ebay.
called a "Motor Start Run Capacitor 2.5uF 450VAC 50/60Hz"
It was an easy installation and fixed the issue straight away.

Here is the link to see or buy them. These are Chinese made.

https://www.ebay.com.au/itm/CBB61-Appliance-Motor-Start-Run-Capacitor-2-5uF-450VAC-50-60Hz-2-2-pins-C427/272313476562?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Dogtor Frankarnstein
[Smile]

Posted by Barry Fritz (Member # 1865) on July 20, 2018, 08:49 AM:

Yes, it does Terry.

Posted by Maurice Leakey (Member # 916) on July 20, 2018, 09:37 AM:

The capacitor which Frank mentions can be obtained from China. At this low price there should be no import duty or VAT payable.
https://ww w.ebay.co.uk/itm/CBB61-Fan-Start-Motor-Running-Capacitor-450V-1-1-2-1-5-2-2-5-3-3-5UF-18-UF20UF/172821436043?hash=item283cf5d68b:m:moZzTlKn9dovbtdW8OzNFOA
Make sure value and pack size is selected - 2.5UF (450v).

Posted by Tom Photiou (Member # 130) on July 20, 2018, 03:52 PM:

Yes my problem early in 2017 was the capacitor. Mine went with a loud bang, literally. Were watching a film and five minutes before the end the projector suddenly slowed down, then,(because i didn't switch it off immediately), there was a loud pop followed by a horrendous amount of smoke which started to fill the room. When everything settled this was the mess i found. It took ages to get rid of the stench in the room and clean out the mess.
http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=5;t=001543

Posted by Can Sanalan (Member # 5988) on July 22, 2018, 07:04 AM:

When I bought the projector it was in need of major servicing so I took it on as a project to repair it and having it running as a back up projector.
With the help and advice from Tom Photiou I managed to get the projector running. Cleaned out all the old grease and relubed the parts that needed it. Same with the cam tank. Took it apart and gave it a thorough clean. New belts from eBay and cleaned the amps crackling switches.

I agree with Barry, it’s the motor toccam tank belt that’s slipping. I ran the projector with it’s cover off and at some points the belt would just stop turning but the motor was still spinning. I’ve made sure there’s no grease on the pulleys or the belt. I’m wondering if I buy another belt would I have the same issue or maybe a new belt will solve the problem.

Is there any way I can add traction to the current belt I have, considering it’s new or is there a brand of belt that you can recommend which is guaranteed to have better grip on the pulleys for this projector?

Thanks

Posted by Can Sanalan (Member # 5988) on July 22, 2018, 07:06 AM:

When I bought the projector it was in need of major servicing so I took it on as a project to repair it and having it running as a back up projector.
With the help and advice from Tom Photiou I managed to get the projector running. Cleaned out all the old grease and relubed the parts that needed it. Same with the cam tank. Took it apart and gave it a thorough clean. New belts from eBay and cleaned the amps crackling switches.

I agree with Barry, it’s the motor to cam tank belt that’s slipping. I ran the projector with it’s cover off and at some points the belt would just stop turning but the motor was still spinning. I’ve made sure there’s no grease on the pulleys or the belt. I’m wondering if I buy another belt would I have the same issue or maybe a new belt will solve the problem.

Is there any way I can add traction to the current belt I have, considering it’s new or is there a brand of belt that you can recommend which is guaranteed to have better grip on the pulleys for this projector?

I’ll also take a look at my motor just in case and see if I have the same issue with any leaks.
Thanks

Posted by Maurice Leakey (Member # 916) on July 22, 2018, 12:09 PM:

It sounds if you have the wrong belt. Suggest you contact the seller for advice.
Only today I picked up a similar model from my service agent. He showed me a belt which he had replaced as it had no "give", it was impossible to stretch it.
Also, the nitrile belt inside the take-up arm had been replaced with a spring belt. [Embarrassed]

Nice new belts now fitted and a thorough overhaul has made it "like new".
I suggest you get it looked at professionally.

Posted by Richard C Patchett (Member # 974) on July 22, 2018, 01:59 PM:

Greetings Gentlemen
All have good advice
But nobody mentioned the bearing that sits on the back arm that (the screw holds the assy in place )
Has it been repacked with grease ??
Also the shaft that goes back into the arm has that been greased?
The motor belt may be worn out and missing a tooth
The Take up belt is it the flat one or is it the round one? Elmo used 2 different ones
When the film stops taking up is the bottom gear still turning?
Hope this helps
RC

Posted by Nantawat Kittiwarakul (Member # 6050) on July 22, 2018, 08:27 PM:

"...and at some points the belt would just stop turning but the motor was still spinning..."

That's obviously the cause then. [Roll Eyes]

Posted by Tom Photiou (Member # 130) on July 23, 2018, 04:08 PM:

where can we still buy decent/genuine Eiki belts for these machines?
i dont trust the ebay sellers who seem to have complete sets but they are un branded.

Posted by Richard C Patchett (Member # 974) on July 23, 2018, 05:07 PM:

Greetings

I am a Eiki parts distributor Here in the USA
Please visit my web site
RC

UBB.classic^TM 6.3.1.2