burned out motor

cdog4w · #1 03-01-2004, 11:24 AM

I burned out my motor this weekend and I was wondering if there might be anything salvagable? I'm hoping the armature is salvagable since it's my only 4wd motor. I have a 2WD that I can use in the meantime, but I'd obviously much prefer to keep 4WD.

I'm guessing that the damage done when it burned out (some grit got into a gear and bound it up) was excessive arcing on the com burning it up. Can this kind of damage be cleaned off? Someone told me you clean comms with an eraser, but I dunno if that would be enough.

Just to let you know, I haven't opened the can yet, so I haven't surveyed the actual damage.

mde · #2 03-01-2004, 11:10 PM

Hi Cdog,

We cleaned one of our comms with an eraser tonight. That wasn't enough for the motor we burned out with the 7 volt battery pack though.

There are a lot of ways to put upgrade motors in a mini x if you look around this board. Mr. Big over in the xmods forum put a big block motor in an xmod so you could do it to your mini x too.

You can put a 180 in it, you have to trim the motor box a bit.

I saw a post recently here where a guy put a replacement motor on top of the can of his mini x motor and used the original armature with a gear installed as his drive shaft.

cdog4w · #3 03-01-2004, 11:38 PM

Yea, I saw that. Interesting solution to mounting a separate drive shaft. It wasn't clear, but Assuming he took the actual armature/comm etc. off and it was just the drive shaft left rotating in the emptied out can, not a bad way to do it. The empty motor cans don't weigh that much...

I was staring at it today thinking about that, if I order an extra motor mount, I might be able to squeeze it in where the plastic holder for the endbell of the current motor can fits into. I'd have to shave it down to the floor first, but I don't think it would fit between it and the pinion as it is now. Shame that the put a whole in the chassis for the motor can to fit in, otherwise it'd be easier to mount another support. I'd feel better about it if tiny ever restocked and I could pick up a new chassis :P (hint hint)

I guess my problem would be mounting the new motor and finding the right gearing for it. I can't really fab any parts (unless someone has a how to

so it would be tough. If I do anything, I'll let you know, in the meantime I'll be mounting a 2wd motor I got from tiny in my last part order.

Cian · #4 03-02-2004, 07:15 AM

Quote:

Originally posted by cdog4w
Assuming he took the actual armature/comm etc. off and it was just the drive shaft left rotating in the emptied out can, not a bad way to do it. The empty motor cans don't weigh that much...

Well that's the plan anyways, we were just talking about it,haven't done it yet. You assume correctly though, all i was going to leave was the can and the shaft, and dump the wires/brushes/magnets/magnet clip/caps/armature...

mde · #5 03-02-2004, 10:19 AM

I think using the can and armature as the drive shaft is a good temporary solution. This could get you running again quickly while you work out another solution.

Go to a lhs that is into model rail roading and get some styrene sheet to make your mounts from. you can also get square and round tube and solid bar. You can also likely get aluminum or brass as well.

It is easy to cut and strong enough for the loads encountered in rc.

mde · #6 03-02-2004, 10:47 AM

I just thought of a possibility for rebuilding burned out motors.

If it is the comm that is damaged is it possible to clean up the surface and then put a sleeve over it made from copper tubing and then solder it to make a reconditioned surface? You'd also replace the brushes at the same time.

This is assuming the damage is to the comm not the armature.

For my own knowledge and others what fails or is damaged when a motro burns out? If there are different types of failures please describe them.

mini-xmen · #7 03-02-2004, 01:16 PM

Hi,

for those who have not done any motor conversion still.
I burned 3 stock 4wd motors, all of them lost their armature.
They get to hot!!!
Now I am using a 2mm steel shaft with 2 shaftholders, one in the original place the other on the hole which is in the chassis alright there.
No motorcan, in the back there is a 2x6mm bearing!!
The motorholder is a small metalplate bent.
I drive 1:1 or 1:1,2.
The pinion on the shaft is 25t (no trimming needed) and on the motor there is an 25t. I drive also with an 30t on the motor.
Now the 180 is staying cool as the original esc.
No burnt motor anymore!!!
see the pictures

Bye

mini-xmen · #8 03-02-2004, 01:20 PM

A second pic!!

The motor is a GPM MH038 torque.

But still to slow!!
Does the stock esc hold up 9,6V??????
I would like to keep up with the 1:10 touring cars!!!!

Bye

mini-xmen · #9 03-02-2004, 01:21 PM

Sorry wrong one, but as you see I am new here!!!!

Sorry!!

mde · #10 03-02-2004, 01:57 PM

That looks good, I'm going to work on doing that!

cdog4w · #11 03-02-2004, 03:27 PM

Ah, I was wondering how that 25t pinion meshed with the diff, but then I saw that the motor was facing opposite what I thought. Very cool and smooth looking.

Do you find that the higher CG is causing problems?

Also, you say you put a bearing where the endbell used to sit (theres a little curved spot for it to slide into). Did you make a cover plate or something to hold the bearing in place? Did I misunderstand and you only have 2 supports on the shaft? The existing hole you are talking about is right where the ESC switch is supposed to mount and would be in the center of the car. So with just those 2, then end of the shaft would be unsupported. Just trying to clear up your design.

Glad you decided to post, will probably help save my car's 4WD :P

mini-xmen · #12 03-03-2004, 02:52 AM

To hold the bearing at the rear diff, the engine plate is so long to cover all 4 posts. You have to cut the two posts in the front, where formerly the motor was tied down, they should be the same height as the rear posts.
So the metal plate, which is bent in the front to hold the 180, elongs till the rear bearing to hold it down.
So the shaft has 3 bearings!!!
After this modification, you can use any 130 (S01, S03, Yeah, ...) or any 180 (GPM, HPI, or even the HPI modified with 30t).

Bye

ben1112 · #13 03-03-2004, 06:55 AM

WtF.... im the guy who came up on the idea of mounting another motor on the stock can... i also had the EXACT same idea as you.... wth.... i have not been as lucky as the gears strip easily and i couldnt get the right sizes... i was just think of resorting to belt and POW you did it... please tell me what tooth you are using and what material.. another problem i faced is how to secure the shaft. i found that the gears i used are too big and had to trim the sides of the battery compartment, but alas, when i tried to put the motor, it stripped the gear becuz it was brass(from toothbrush). where can i find good stock motors bigger than 130?

ben1112 · #14 03-03-2004, 06:59 AM

that's way too cool.. just what i had in my brain, what did you make the mount out of? how did you get the gears to mesh perfectly? the solution to your slow car is because it has too much torque and little rpm. try to change gearing if you can. i think that is another problem.

im sooo stuck with solving the problematic x that i feel like going back to 1/10 and buying a mini z. help me someone..

mini-xmen · #15 03-03-2004, 07:50 AM

The bent steel plate is about 0,75mm thick.
To mesh the theeth correct, I can slide the motor up and down a little.
The gears are from local hobby shop, 25t or 30t modul 0,5.
You only have to cut 2mm from the backside, because they are to thick, drill a thread into them. No drilling on the chassis!!!!!
I was driving for around 10 hours tracktime or so and only very small signs of use on them.
I stay with the original ratio or if you put the 30t on the motorshaft you get a final ratio 3,8, original 4,375.

You can buy the stock motor from the HPI Micro. It´s very good for the mini-x.

bye