2200kv Torq motor, how do I remove the rear bearing?
 

Ok, my Flux is under going an overhaul to check everything and I found the front bearing on my motor to be a little gritty so im gonna go ahead and replace it. I for the life of me however cannot figure out how to get to the rear bearing on the motor. I removed the 3 tiny little screws on the back plate, but I cannot see a way to safely remove the rear motor cap without using excessive force.

Am I missing something? And where can I go to purchase some high quality bearings for the Torq motor?

http://i100.photobucket.com/albums/m...eFlux/mmm3.jpg

Also, im gonna go head and plug up those air holes in the front bell cap with some set screws to keep the dirt out. Any problem with this?

I also recently found that my fan is starting to make growling noises. I blew it out with the air compressor so I don't have to spend $12 on a new one but I"m wondering if I could even run this MMM system without the fan?

http://i100.photobucket.com/albums/m...eFlux/mmm2.jpg

I was also surprised to see how many little rocks and dirt got on the PCB board, is it gonna be able to last with that much dirt/grit? I also found the fan cable to be nearly cut from the edge of the pcb board so I put some electrical tape on it to hopefully save it.

http://i100.photobucket.com/albums/m...eFlux/mmm1.jpg

you know...ive never opened my MMM case...nor the motor :lol:
but...you should never spin the fan over with a compressor, (this only apply the brushless fans i think) cause it causes back EMF that can fry the fan.

I do not have a motor like that, but you should be able to take a phillips screwdriver and hand hammer the bearing out.

Unfortunately i've done that several times :whistle:

That bearing looks fine from here. Why mess with it?

it might be a press fit.
in which case, you will need to press it out, not bash preferably.

as for bearings, look up either some genuine ones or Acer bearings.

And you can get the bearing number right off the bearing too -- can even read it in your post. :)

That is an NMB (nippon miniature bearing) 625ZZ ABEC bearing. Chrome steel, double shield.

Manufacturer's web site:

http://www.nmbtc.com/bearings/

5mm x 16mm x 5mm

And I agree - -the bearing looks fine. Doesn't look like there is any issue.

It's both press fit and glued in place.

Wow, no wonder I couldn't hammer that sucker out, it didn't even budge. I'd basically have to destroy the bearing to replace it then? I took it to the LHS and my main guy their said it makes a little bit of noise and some resistance but it should be ok for a bit longer.

I should probably take a movie of me spinning it and you can tell me how good or bad the bearing is.

EDIT: Heres the video, tell me what you think. And whats up with the shaft being able to move back and forth like that? Is that bad?

[YOUTUBE]6bsIeIC2BHY[/YOUTUBE]

You chould be able to get the bearing out if you heat it up with a heatgun ! it works great with nitro engines anyway :lol: the bearings just fall out ! But they aren't glued ofcourse :sarcastic:

i'd say you did more damage by TRYING to get it out!

you will need to heat up and press it out, if you have a hydraulic press, that would be ace!
might be able to use a large vice and some correct sized ramrods.

Well,

The bearing doesn't seem to be bad -- it will have a little resistance to turning because of the bearing shields.

And it looks like you lost the front bearing spacer -- it's not in the video. That's why the shaft moves so much.

Errr, I don't recall seeing any kinda spacer at any point and I dissasembled it slowly over the table so I woulda seen/heard it fall.

There is a small brass spacer that goes between the bearing and the rotor balancing assembly. It's a small piece of thick wall brass tubing, about 6-7mm in length.

Errr nope, never saw anything like that and this is the first time I opened up the motor. Well this is just great.....

EDIT: Checked all over the desk area and even the garbage and no sign of a brass spacer. Now what?

I have seen tons of bearings that are bad but look great on the outside. When you get small particals of dirt and grime stuck between the race and balls of the bearing it can cause the ball to stop spinning and to spall the inner surface of the race and damage it. Usually it will feel gritty and may hang up when you spin it. Its like you are pushing a shopping cart and run into a pebble and the wheel stops but you end up pushing it another foot or so (or like riding a skateboard and hitting a pebble). You can't see it from the outside, but you can feel it.

Shields do not contact the inner race so there should be no resistance for a bearing that small when turned by hand. If there is grease in it may not spin freely, but you should not feel any grit or clicking, it should be smooth as silk. If it is gritty change it since you have it apart if you don't then you may get to a point where the bearing inner race stops all together and the shaft turns and the inner race does not which will destroy the shaft.

As far as getting the old one out if you do not have a hydraulic press use a heat gun as mentioned earlier and a drill press if it is glued then you will need the heat gun so you don’t damage the bearing housing (from pressing too hard). Use a socket that is the same size of the inner race to press the old one out since you are not worried about damage to the bearing at this point. When you press the new one back in you can use sleeve retaining compound to hold the bearing in and its available at most auto supply stores (Advance, Hi-Lo, Checkers (or its affiliates) carry it. When pressing the new bearing in make sure to use a socket that is the same size as the outer race of the bearing and press on the outer race only. If you press the inner race to put the bearing in you can damage it because the inner race will press on the balls which will press on the outer race, this will cause indentions in the race and you will have a bearing that clicks and be back to square 1. You can also damage the balls as well pressing on the inner race.

A 625ZZ bearing comes back as a 5mm ID, 16mm OD, 5mm Wide bearing the ZZ is for shielded both sides.

If you live in or near a large city or in an industrial area you can buy bearings from places like Motion Industries or Applied Industrial Technologies, King Bearing or Purvis Bearing. An ABEC 1 bearing should be fine since most of the motors I have seen use these although I would feel better with a more precision bearing like an ABEC 5 along with a seal instead of a shield.

Jeff