View Full Version : Motor maintenance

04-10-2007, 12:53 PM
I have heard alot of people say about 'breaking-in' a motor - what do they mean by this and is it necessary?

I have also been told that commutator drops are essential and can drastically extend the life of a motor - is this true?

04-10-2007, 01:33 PM
Both only apply to brushed motors.....for fairly obvious reasons.

Breaking in basically shapes the brushes better to the commutator. It can give a little more power and longevity but it's certainly not necessary. There are several ways of doing it....I prefer the underwater version. I used to break in bigger brushed motors (don't have any left now :)) but never really bothered with S400 and smaller. I've just replaced a S400 which was getting a bit iffy....but then it was 5 or 6 years old ;).

I've never used commutator drops....but if my 5 motors already last for >5 years without them I don't think they can be regarded as essential for decent life.


04-10-2007, 04:12 PM
Hi penguin,

I "broke" in my Super Cub's brushed motor. I think its a good idea, not sure if its necessary but certainly it does not hurt anything.

When I got my cub I took it to a big parking lot and just taxied it around for a battery. (the steerable tailwheel is great)

Thats a good way to get familiar with the plane and break in the engine at the same time. PLUS taxing away and towards you will help with the reverse orientation you'll get when the plane is in the air heading towards you.


06-24-2007, 03:33 AM
This is so strange. I have been playing around with this new 480 motor using two 'D' akaline batteries that are taped together. It has been running so good although the total voltage is only 3.

I put this motor into the gear box assembly, attach a 10 X 8 prop and hold the wires on each end of the batteries. I have been breaking it in like this now for about two weeks while I watch tv.

I crashed my Super Cub today and the motor took a beating to say the least. When I installed this new spare motor into the cub it hardly turns over. The Cubs ESC lets me know that something is wrong. I took it out of the plane and tried the two batteries I was using before.

Same ole darn thing, the motor hardly turns over. It acts like its lugging real hard. Did I frie it using those 'D' batts??????? It sure acts like something is rubbing inside although I cannot see anything wrong with it.

Please pimp my motor for me. I am in need for answers.

Bob Bowman
Selah, WA

06-24-2007, 09:31 AM
The general idea is to break in the motor using a low voltage and NO LOAD. If you've been running it with a gearbox and prop you haven't so much been breaking it in as wearing it out :(.

But the real problem is probably that you have worn the brushes in correctly for the direction of rotation with a gearbox and you're now trying to run it direct drive i.e. in the opposite direction. That never works. You have to break a motor in running in its intended direction of rotation.


06-24-2007, 04:53 PM
Many thanks Slipstick, you hit it right on the head. For the most part I was running it in the correct rotation.

I did not think it would hurt it so I would reverse the wires and let it run backwards. Looks like the motor will get trashed. From now on I will run them the right direction.

Say while I have you here what are those little brown round things on the front of the motor for????????? Are those resistors maybe to work in conjunction with the ESC?

Thanks again,


06-24-2007, 05:53 PM
If you mean little brown things on the BACK of the motor connecting the terminals to the case then they are capacitors to reduce radio interference from the motor. If not....I dunno ;).