8mm Forum: GS 1200 MAIN MOTORS

This is topic GS 1200 MAIN MOTORS in forum 8mm Forum at 8mm Forum.

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Posted by Bill Parsons (Member # 244) on August 29, 2004, 01:09 PM:

I have had an email from Kevin asking about GS1200 main motors, thought I would share the reply with everyone, there is a small UK company that can rewind these motors, (F.W. MASON. In Matlock, Tel:- 01629 650738)cost about £85. I have fitted one of these and it seems fine, I can not claim the credit for finding this company, it was discovered by Simon McConway.
One other point worth a mention with these motors, if you dismantle the motor you will find a ring of resistors between the windings, these should be over 1meg ohm each, they tend to reduce in value or sometimes virtually short out, causing the motor to behave erratically these resistors can be removed without any problem they are there to suppress interference on the audio (crackle) but I have never noticed any problem after removing them. But ONLY remove them if you have problems with the motor.

Bill.

Posted by Chris Quinn (Member # 129) on August 29, 2004, 02:20 PM:

Nice one Bill, thanks for sharing.

Chris.

Posted by Kevin Faulkner (Member # 6) on August 29, 2004, 04:04 PM:

Nice one Bill.
This motor is behaving very eratically and yes the resistors are down to a few ohms each. Will do as you suggest and report back.

Kev [Smile]

Posted by John Clancy (Member # 49) on September 01, 2004, 02:50 AM:

Here Bill, does this mean the motor that came out of my machine is repairable? The one that burned out and filled the room with smoke.

Slight exaggeration with the 'filling the room' bit but you get the picture.

Posted by Tony Milman (Member # 7) on September 01, 2004, 11:12 AM:

That is indeed very handy to know. Thanks Bill.

Does anyone know what the specifications for this motor are? Apart from the physical size of the motor and te fact that it needs to respond to variable speed control what other essential aspects should be considered?

The reason I ask is that I know a UK company that manufacture fans and inport variable speed 12v and 24v motors from around the world and I have asked them to consider replacements

Tony

Posted by Bill Parsons (Member # 244) on September 01, 2004, 01:18 PM:

John, your motor is beyond first aid, but could be rewound, I have spoken to the chap today, the cost is now £95 + VAT but it is still worth it so you have a spare to keep the projector running.
I think we should support this chap, he is the only one I have come across willing to repair a small dc motor, unless anyone else knows any different?

Tony,
The running voltage of the motor will of course depend on what speed you are running at and where the variable control is set, but on average about 24.2v for 24fps and 19v for 18fps, this will vary a bit from one machine to another, but a new motor would need to be rated at over 24v as some people run at 25fps. The amount of revs of the motor would be hard to calculate but I think I could mod the control circuit to match the motor, the built in servo/tacho coil is 170ohm. Believe me it is not an easy motor to find a match for, I have spent many hours searching!

Bill.

[ September 01, 2004, 02:26 PM: Message edited by: Bill Parsons ]

Posted by Rob Young. (Member # 131) on September 01, 2004, 02:46 PM:

Hey John, that motor didn't burn out while you were running your print of "Raiders" did it [Wink]

Posted by John Clancy (Member # 49) on September 02, 2004, 02:07 AM:

No Robb, I don't suffer from 'The Raiders Curse'! It packed up during the lead out on 'The Terminator'. Now how lucky was that? Any other point and I'd have burned a frame out.

Bill, getting him to rewind the motor sounds like a great idea to me. Are you coming to the BFCC on 23rd October?

By the way, the GS has been wonderful ever since you repaired it.

Posted by Tony Milman (Member # 7) on September 02, 2004, 05:40 AM:

Bill/John/Mr Elmo...

What is the situation re the fan motor? Is this as vulnerable and as hard to replace? Will they re-wind that one as well?

Tony

Posted by Bill Parsons (Member # 244) on September 02, 2004, 01:08 PM:

John.
Pleased the GS is working well, it looks as if I may be working on the Ealing date, I will let you know.

Tony.
I have repaired many GS1200 and never had a fan motor fail, the lead in filters sometimes break, but these are easy to replace, a replacement for the arm motors can usually be found, it is just the main motor that is a problem.

Bill.

Posted by Kevin Faulkner (Member # 6) on September 02, 2004, 06:00 PM:

Bill, as you know I have also been looking for hours on the net for suitable replacement motors for the main and takeup.
I did think that it might be possible to find a motor without the tacho magnet disc and coil as these could of course be taken out of the duff motor and mounted externally on the rear of a replacement motor.
I have found some motors which could be used. They are made to order in China and of course need a minimum order of 10,000 units in most cases. Some of these companies will actually make motors to a certain one off spec but again this would be expensive and the minimum order would be prohibitive.
Tony, Like Bill I have never seen a Fan motor fail yet. They sometimes get a bit dirty from carbon dust but a strip down and clean will normally cure any erratic behaviour.
I am also going to check with a couple of motor rewind companies we have here locally to see if they can undertake this job and what the cost might be.
BTW As you have probably guessed by now my friends motor windings are shot not the thermisitors in side the motor. So for the moment I have a downed GS here [Frown]

Kev.

Posted by John Clancy (Member # 49) on September 03, 2004, 02:26 AM:

Not the Xenon Kevin?

Bill, if you can't make Ealing I'll send the boys round!!! And if you still can't make it how about sending the knackered motor off to Mr. Mason? I'll send you the money to cover the postage and contact him directly to arrange payment for the repair and return. It would be a good exercise for us all to confirm the work is worthwhile (as I'm sure it will be).

Posted by Simon McConway (Member # 219) on September 03, 2004, 03:34 AM:

I can already confirm that the rewinds are worthwhile; I had mine done at Masons after locating this company. The motor is steady in it's speed, though a little noisy on return. However, this is quietening down, the more the projector is used.

Posted by Kevin Faulkner (Member # 6) on September 04, 2004, 06:46 AM:

John,
No NOT the xenon. This is a std GS which belongs to friend of mine. His motor started to run slower and slower. I put in a spare motor I have had by me for years into his machine and all returned to normal. I am not however prepared to sell this spare motor I have just incase the xenon should need it at a later date. My freind was quite understanding about that.
What I did find in his machine was that the shutter assay was rather stiff to turn by hand which had put extra strain on his motor. On closer investigation I found that the grease that Elmo had used on the claw pivot point had gone hard. I have stripped the assay down, cleaned and relubed it and now it runs really easily. So it time to get his original motor rewound so that the machine can give him another 30yrs of use.

Kev.

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