Maintenance for this brushless DC motor

Thread Starter

Bronxio

Joined Jun 7, 2020
13
Hi! I have this 30V brushless DC motor (MD-96407YH, from a Numark TT500 DJ turntable) that makes some soft noises while spinning (I guess grazing). It had some heavy use.

I've never opened a motor before (just helped my father to open a three-phase alternator of a wind turbine). I've seen smaller brushless DC motors maintenance videos, but I wonder if this could be -more or less- easily opened and fixed (hope it's not the axis that is blended), so I can extend its life. The three screws in the white plastic ring are under a metal part (with two holes to sit the platter) that I don't know how to remove.

So, my questions are:

  1. Oil is not for brushless motors, right? (no contact is expected if everything is ok)
  2. do you think it's viable to fix it, or would be too much for a standard technician without specific tools?
  3. And if it's (maybe) possible, what would be your procedure to try to fix it? Of course, I have no notice about a manual service: I mean how to do it just observing and trying.

I attach photos of this model:

288128.jpg

288129.jpg
Thanks for dropping by.
 

MaxHeadRoom

Joined Jul 18, 2013
21,594
Why do you say oil is not for that BLDC motor?
It should not be a problem if done in moderation.
Appears to be brass or phosphor bronze, which is the more common.
It almost looks as if the top bearing plate has to be removed to access the screws.
Can the end plate be released from the plastic with slight upward pressure?
Max.
 

Thread Starter

Bronxio

Joined Jun 7, 2020
13
Aw, didn't see the reply. Thanx for it, Max!

I can't release that plate in that way, but now I realized that, although there is a little bad angle, I could use the two holes to reach the screws in the white ring. I'll try and tell if I can open it.
 

Thread Starter

Bronxio

Joined Jun 7, 2020
13
Ok, I've tried, but the end plate didn't move either. I don't know if they made it to never be opened again (not surprised if so). I guess I'll try just with the oil then.
Why do you say oil is not for that BLDC motor?
Because I thought there wouldn't be any contact between the spindle and the rest. I thought it wasn't the same kind of motor than the Technics SL-1200 Mk2 as well, but now that I looked for it, it is... and its instructions recommends lubrication after 2000 hours of use.

By the way, Technics says only use the oil they provide(d), but I guess the only mandatory feature is that the oil is quite refined, so there won't be big particles, right? I mean, I could use a WD-40 multi-use, for example?
 

Thread Starter

Bronxio

Joined Jun 7, 2020
13
Happened something funny. I've tried to unscrew the three screws of the white ring, I did enough to pull the ring, but it's impossible to do it completelly because the end plate. So I screw them again, and the grazing sound dissapeared. It's hard to me to believe that it was just that.

Anyway, an old sound keeped sounding. One like when you pass a card over a fence with sticks ("trrrrrrrrrrrrr" <-- the strong Spanish "r" ) very low, you must put the ear close and be in silence (if my memories do not go wrong, it wasn't at the beginning). So I used WD40 just in case could fix that, but it didn't.

I guess that sound means something more difficult to fix, but it maybe natural aging. I think I won't go further, because that motor is not in production anymore since some years ago.

Thanks for your help, Max! Much appreciated :)
 
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