M-55 motor pause question

Hi Everyone,
I have a 1970 M-55 and replaced the original motor some years ago with a newer smaller Musser model. It has been flawless until lately the motor pauses at slower speeds. At first I thought the paddles needed oil, but traced it to the actual motor having little pauses (almost a little stop start motion) at slower speeds. Does this mean the motor is on its way out or just needs adjustment? Any advice or insight on this?
Thanks
Rusty

Rusty,

If your motor has little metal flaps on it, you could try putting in some 3-in-1 Motor Oil (make sure it says "Motor Oil" as there are different 3-in-1's).
http://www.amazon.com/3-IN-ONE-10045-Motor-Oil-Pack/dp/B0083V8MMG

My old Deagan motor was hesitating and I put in a few drops of oil in each of the openings and things are running smoothly now. Note, I am not sure how much is too much, and how frequently oil should be used; I don't have a manual. I believe the newer types of motors (e.g., Oriental) don't have these flaps though. Post a picture if you don't see what I am talking about.

Barry

Barry I don't see any flaps on the motor. Thanks for the oil info. I put a picture on the original post.
Rusty

Right, Rusty. The more modern motors as in the one pictured, don't have the flaps for oil.
I don't know if it's the motor giving you trouble, or the controller. Look at the sticker on the motor. Does it say Oriental Motors? If so, give them a call. They might be able to help. e.g.,
http://catalog.orientalmotor.com/item/all-categories/us-series-ac-speed-...

Barry

Thanks Barry..It is made by that company. I will give them a call. I'm really hoping not to have to purchase a whole new motor.
Rusty

Barry...called them and it sounds like a bearing issue in the motor itself. The good thing is you can order the motor separately from the controller for about $100. This much cheaper than I would have thought and probably around the same or less expensive than getting it worked on.
Thanks again for your help!
Rusty

Cool, Rusty! Glad to help.

Barry

Electric motors are designed to run at around 1400rpm and are noisy. This is why vibe motors are problematical, they are used in exact opposition to the design spec of the motor.

The little metal flaps that were mentioned is actually a fan, which is used to draw air into the motor and cool the copper windings. I would never suggest putting oil into an electric motor. It is a good way to create a short circuit. The oil should be applied very sparingly to the bearings which are at either end of the armature (the bit that spins). Dry bearings, or worn bearings will cause the stutter, because the torque at low rpm is also very low.

The armature is a cylinder with copper wires running inside it. The outside of the armature is divided into segments that are insulated from each other. The field coil wraps around the armature and consists of two sets of copper windings that create a magnetic force. Mains electricity is variable current, like a sound wave at around 50 hertz. The electricity goes through the field coil and because of the wave it alternates the polarity of the magnetic force. This pulls the oppositely charged segments of the armature, and therefore the motor turns.

Therefore, if the insulation on the armature has failed, the motor will not turn. They tend to stop, rather than deteriorate.

When I have instruments in to repair with electrical problems, the place to start is the plug. Electricity passing though copper generates heat which causes the copper to expand. This means that every year the plugs should be opened, and the connections tightened. Then check the cable for damage cuts, squashing, etc. Cables break down in time as the repeated cycle of heat causes the copper to work harden and become brittle. To check for a cable break, plug it in, put the motor on fast, then wiggle, flex, bend the cable down its entire length - if the motor stutters, that is your problem.

Then you are at the speed control unit. Musser fit cheap switches which break, equally the pots aren't that great either, and also break. The old vibes had mercury switches which never fail, but the rheostats they used to use do. A rheostat is a copper coil (heat) with a pointer that connects at some point along the length. Potentiometers use the same principle, but are smaller and most often made from graphite or ceramics (can't remember exactly)

There is a lot of information in the above, most of which applies to all vibes. However there are lots of specific problems that are instrument specific. I have been fixing vibes for years, so I have come across most things. I hope this helps.

regards
Paul Jefferies
Orchestral Percussion

PS Don't ask a musician about motors, speak to an expert - electricity kills, at the very least it could burn down your house!

Hi Paul,

I think we might be talking about different types of motors. Attached is a copy of my Deagan Model 580 Traveller Vibraharp Assembly and Care pamphlet, and a picture of my motor (removed from vibes). There are two tubes attached to the motor for oil.

Barry

Hi Barry

Sorry for the slow response, I have moved house and workshop, so things are chaotic, and my hours are full.
In my reply I was trying to be as general as possible. There are lots of different types of motor, and it was not uncommon for manufacturers to put oiling cups above the bushes. I am not 100% on your particular motor, but my best guess is that the armature spindle rotates inside bronze bushes at either end. The bushes will be free moving (ish) in the casing to allow for self alignment. Either side of the bush there will be a felt washer. The felt prevents oil from being sprayed around inside the field coil, and acts as a lubricant reservoir for the bushes. The cups in your picture are essentially funnels - don't fill them. Most motors I see like this have been over oiled, and residues are visible inside the coils.
Alternatively, the armature spindle might be indented on the ends of the shaft, and a single steel ball at each end spins. These types of motors are identified by adjustment screws at either end of the armature, and therefore the armature ends in a worm gear.

If it is the first type, it is straight forward to open the casing and clean any oil residue off the spindle which might be causing a sticky point. The second type are more tricky.

In terms of your initial problem about low speed running, my initial reply gives a fault finding sequence. It is not necessarily a motor problem. That is the most expensive part of the system, whereas all the other parts are easy to eliminate from the list of possible causes.

Thanks, Paul.

Barry

Hi Barry,

I am new to this site...

I have a Deagan Traveller and I want to clean it up and maintain the motor as best as I can...

I noticed your post mentioned you have a "Deagan Model 580 Traveller Vibraharp Assembly and Care pamphlet"...

I was wondering if I might be able to pay you for either a photocopy or scan of the entire pamphlet...

Thanks for any information.

Jesse Elliott
Toronto, Ontario

Vibe motors are more problematic than the others as they are designed to run with a high potential speed .Even I don’t think putting an oil to these motors is a good practice as it pave way for the short circuithttp://www.powered.com/