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Motor Vibrations

I'm in the midst of tuning/upgrading a Well Tempered Classic. The original AC motor has a significant vibration, so I've been experimenting with the Origin Live DC motor and power supply. The OL motor vibrates fairly significantly, too, enough to be transmitted through the belt,platter and into the cartridge. I can also clearly feel the vibration in the belt whien I lightly touch it. I've experimented with different belts (the original rubber plus silk and nylon cords and dental floss) and found that the only way to reduce the vibration tranmitted to the cartridge is to loosen the belt tension to the point that there starts to be some "wow". Do all of you with DC motors experience vibration? If so, how much?

I suspect that I may have a bad motor, but the dealer tells me that the motors do vibrate to some degree. I could change over to Well Tempered's new AC motor which has some circuitry that is supposed to minimize vibration, cogging, etc. (See their website for details)

Any thoughts, suggestions, questions are welcomed.

Thanks
Jim
jimbo3
jimbo3 OP
304 posts
 
Thanks, Tom. He is going to be sending me another motor and if that doesn't do the trick, he's going to send an entire kit. I'll post the results.

Regards
Jim
jimbo3 OP
304 posts
 
I initially ran the motor for 5 days without a load and now, after running the motor under full load for a couple of days this week, it seems to have quieted down dramatically and the problem seems to have resolved itself.

Thanks to Jay at Audio Revelations for his assistance and persistence.

Jim
dougdeacon
3,338 posts
 
Jim, Not surprising if a motor needs a little run-in to settle down I guess. Just another audio voodoo mystery thingy.

Glad to hear the problem seems to be resolved. Especially since I kept forgetting to measure my motor pod like you requested :(
markeee
2 posts
 
1. It is caused by unbalance of the rotor, coupler, coupling and driving wheel (brake wheel).

2. If the iron core support is loose, the inclined key and pin are invalid and loose, and the rotor is not tightly bound, the rotating part will be unbalanced.

3. The shafting of the linkage part is not aligned, the centre lines are not coincident, and the centring is not correct—this kind of fault caused by poor alignment and improper installation during installation.

4. The centre lines of the linkage part coincide in the cold state. Still, after a period of operation, due to the deformation of the rotor fulcrum and foundation, the centre line is damaged, resulting in vibration.

5. The faults of the gear and coupling connected with the motor, the bad engagement of the gear, the serious wear of the gear teeth, the bad lubrication of the counter wheel, the skew and dislocation of the coupling, the wrong tooth shape and pitch of the gear coupling, the excessive clearance or serious wear will cause certain vibration.

6. The structure defects of the motor include elliptical journal, bending shaft, too large or too small clearance between the shaft and bearing bush, and insufficient rigidity of bearing pedestal, foundation plate, some part of the foundation and even the whole motor installation foundation.

7. Installation problems, the motor and the foundation plate, is not fixed firmly, the foot bolt is loose, the bearing pedestal and the foundation plate are loose, etc.

8. Too large or too small clearance between the shaft and bearing bush can cause vibration and cause abnormal lubrication and temperature of the bearing bush.
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