Film-Tech Forum ARCHIVE: Christie MUT Motor Brush Source?

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Posted by Jim Cassedy (Member # 4115) on 01-13-2009, 07:09 PM:

I've got a couple of Christie MUT's at one location that are
at least 30 years old. The motor brushes on one of them are
getting worn down to the point where they need to be replaced.

I hate to spend money buying a whole new motor when all I
really need is a pair new brushes & springs, but I can't
find a part number for the brushes alone.

Anybody know of a source of replacement brushes for this thing?

The motor is a Bodine.
Here's the info from the motor plate:
NUMBER: C10?0102 (One of the digits is illegible, hence the "?")
TYPE: NSF13
1/10hp
115VDC - 1.3Amps

Posted by Mark Gulbrandsen (Member # 72) on 01-13-2009, 07:20 PM:

Jim,
30 years of use is a LONG TIME on any brush type motor. Who knows if they've ever been replaced before or not! I reccomend at least taking the motor apart and cleaning out the carbon... so it doesn't short out the controller card... Also, these motors tend to see a "brush groove" worn into the commutator over this long of period and if it's there may it may eat up a new set of brushes in short order.

BTW: The new motor that replaces that one is 2 to three times the size of the original.

Mark

Posted by Louis Bornwasser (Member # 3063) on 01-13-2009, 08:14 PM:

Any dealer will have these either in stock or from Christie. We also stock them. Louis

Posted by Jim Cassedy (Member # 4115) on 01-13-2009, 11:17 PM:

quote: Mark Gulbrandsen
30 years of use is a LONG TIME on any brush type motor

Well, yes and no. I suppose it depends on how you look at it.

This MUT is located in a 'single' booth, not at multiplex.
So if you think about the amount of time the MUT was actually used over that 30 year period (one day a week or less for about an hour's worth of intermittant duty)- - the motor, although 'old', doesn't have all that many hours on it, relatively speaking.

This particular booth is also equipped for change-over operation and I personally know of at least one 3 year period of time where the MUT wasn't used at all, since all shows were being run off of reels. There may have been other long periods of disuse also that I'm not aware of.

Your advice about dissassembly and checking the commutator for carbon build up and 'scoring' is well taken. I ran carbon acrs off of motor-generator sets for many years and did this sort of stuff as routine maintenance, and I'd planned on disassembling and cleaning/checking the MUT motor when replacing the brushes just because it made good sense to do so.

As for damaging any control card circuitry, that's not an issue with this particular set up. The MUT and the AW3 platters were extensively modified and re-wired many years ago by a local tech who bypassed everything in the AW3's.

Instead of being powered from the AW3, the MUT plugs directly into a wall socket for power, and then you've got to plug a cable from the MUT directly into the platter motor to drive the platter when making up a show.

As for the MUT, it does not have one of the new solid state speed controls. Only a variable autotransformer and rectifier. (and a large wattage resistor) So while a motor short would blow a fuse in the MUT, no real "electronic' circuitry would burn out. About two years ago, I replaced the contact brush in the variable autotransformer, and other than that the darn thing has been working fine.

Posted by Mike Blakesley (Member # 26) on 01-13-2009, 11:29 PM:

quote:
This MUT is located in a 'single' booth, not at multiplex.
So if you think about the amount of time the MUT was actually used over that 30 year period (one day a week or less for about an hour's worth of intermittant duty)-

We have an AW3 from 1980 and we have about the same kind of usage you're talking about. I've replaced the brushes in the MUT at least twice that I can think of. We're still using the original motor, the thing is a tank.

Posted by Donna Sylvester (Member # 726) on 01-13-2009, 11:38 PM:

One of my Bodine's is in the "small motor shop" right now. It slowed down and quit on me last week. Fortunately, I have spares.

Posted by Jim Cassedy (Member # 4115) on 01-14-2009, 10:06 AM:

quote: Mark Gulbrandsen
30 years of use is a LONG TIME on any brush type motor.

I don't want to disagree with Mark because he's usually more than right on these things, but it goes without saying that there's an exception to every rule.

But just anecdotally:
After typing my long-winded rant/reply last night I realized that right here in this room, I have a 1927 Western Electric electric fan with a universal ac/dc brush motor that I've owned since 1971.

There are some periods during summer months that I've left it on 24/7. And I've never replaced the brushes. Just a few drops of oil every year on the bearings. And it runs great!

(Of course I realize the stress and load factors on a motor are much different between a fan and an MUT!)

Posted by Steve Guttag (Member # 268) on 01-14-2009, 11:39 AM:

Not all motors, brushes or even circuits are equal. I'd agree with Mark on this one...30-years, at even a single, would be a long time for this brush. As for the motor...rather than an NSF-13...perhaps it is an NSE-13...which was used in the Christie MK make up table. Part number 598700-061. Not very pricey either.

For motors in general, I've known brushes to give it up with just a mere 1500-hours of use or less and some that seem to last forever. There are different brush compositions thoughout the years, different currents running through them too...all of this adds into brush life. So one can not apply the results of one type of motor and usage to another type of motor and usage and draw a conclusion.

Steve

Posted by Mark Gulbrandsen (Member # 72) on 01-14-2009, 03:46 PM:

Funny... we sent out two AW-3 MUT motors today..... DeJaVu indeed.

Mark

Posted by Phil Ranucci (Member # 3820) on 01-14-2009, 11:19 PM:

Be aware that if you order the new motor you'll need to order a new bracket, also.

Posted by John Walsh (Member # 168) on 01-15-2009, 09:41 PM:

Also be aware that the new motor and bracket just barely fits in the orginal location; bring #6 screws to replace the #8's; that's how close the motor is to the chassis.

Posted by Mark Gulbrandsen (Member # 72) on 01-16-2009, 08:20 AM:

quote: Phil Ranucci
Be aware that if you order the new motor you'll need to order a new bracket, also.

No you don't!! Just drill new holes in the old mount so the motor will bolt down. Leave about 3/8" at the flat end of the motor and MUT side wall. I've done this at least a dozen times. Everythng will work just fine and save some $$.

Mark