Brushed motor break-in failure

[Dave_In_Florida]

I picked up a Losi Insane 370 brushed motor for my MRC. I decided to break it in today before putting it in. I did it the way I used to back in the day, stuck the motor in a cup of water, hooked a fresh battery directly to the motor, dunk and go. It ran good for about 30 seconds, but the motor turned grey/black after only a few seconds. I thought it was strange but figured maybe there was some nasty stuff in the motor. So after about 30 seconds the motor slows down and stopped. I pulled it out, and found the brushes were worn all the way down so the springs weren't putting any tension on the comm. Like I said, I plugged motor directly to battery (2s 1000mah lipo) and used tap water, not distilled. What did I do wrong?

[yoda@4x4]

LOL, milk not water and a good NiMh for break in thats just M2C...

I would clean the come and put a set of new brush's init and go agian...

[Dave_In_Florida]

milk? Seriously?

And why not a lipo? I'm new to lipo's so I honestly don't know. FWIW, I did have a lipo low voltage alarm plugged into the tap so I wouldn't overly discharge them.

[EddieO]

You used the water break in method on a motor you knew nothing about, thats what ya did wrong.

Water break in is rarely used anymore....and its NEVER the same between motor types, what works on one motor probably won't work on another. 7.4 volts is a bit on the high side for most water break ins.....its typically done at a lower voltage.

Your motor is toast....

When you get a new one, 5 or so minutes at 3 volts is more than enough to break in most motors, especially mini motors.

Later EddieO

[Fanfor88]

I learn something new everyday about this stuff. I didnt know you had to break in a brushed motor Does this happen on a RTR truck to? I pulled my Wraith outta the box stuck in a battery and been going ever since so i guess im good. I dont remember seeing anything is the book about this either.

[yoda@4x4]

using milk/water is to help pull the graffiti away from the motor and the useing a low volt at 1amp or so to help get the serration off the motor brushes...

[fred0000]

Originally Posted by Fanfor88

I learn something new everyday about this stuff. I didnt know you had to break in a brushed motor Does this happen on a RTR truck to? I pulled my Wraith outta the box stuck in a battery and been going ever since so i guess im good. I dont remember seeing anything is the book about this either.

it's not required to run, back in the oldschool race days people did everything they could to squeeze every ounce of performance out of their motors, its just to ensure near perfect brush to comm contact.

[Dave_In_Florida]

So seriously, milk. OK.

I'll have to rig up a lower voltage setup, maybe a couple of AA's?

Yoda, do you really think the motor is savable? I would think the comm isn't too trashed since obviously all of the brush material was washed away into the water. What do you recommend I clean the comm with? Could I spray it really well without taking it apart? I swear my crawler is possessed, it has fought me every step of the way since I bought it. I know if I have to open the can I'll end up losing a foot or something in the process.

[yoda@4x4]

Originally Posted by fred0000

it's not required to run, back in the oldschool race days people did everything they could to squeeze every ounce of performance out of their motors, its just to ensure near perfect brush to comm contact.

your right that is how i learned racing now it's a little differant but a lot is the same..

Originally Posted by Dave_In_Florida

So seriously, milk. OK.

I'll have to rig up a lower voltage setup, maybe a couple of AA's?

Yoda, do you really think the motor is savable? I would think the comm isn't too trashed since obviously all of the brush material was washed away into the water. What do you recommend I clean the comm with? Could I spray it really well without taking it apart? I swear my crawler is possessed, it has fought me every step of the way since I bought it. I know if I have to open the can I'll end up losing a foot or something in the process.

to be honest i don't know for sure i would look and see if the come has and wear or score marks and if it looks good put a set of brush's in it and go with it

[killswitch]

Originally Posted by Dave_In_Florida

So seriously, milk. OK.

I'll have to rig up a lower voltage setup, maybe a couple of AA's?

Yoda, do you really think the motor is savable? I would think the comm isn't too trashed since obviously all of the brush material was washed away into the water. What do you recommend I clean the comm with? Could I spray it really well without taking it apart? I swear my crawler is possessed, it has fought me every step of the way since I bought it. I know if I have to open the can I'll end up losing a foot or something in the process.

Please don't use milk... or any other dipping method to break it in. Break your motor in dry at a low voltage like Eddie said. I guess you could use AAs, but another option is to use your ESC to run it. You can vary voltage using the throttle channel trim. As far as your motor goes, the only real way to clean the comm is with a lathe.

[Fanfor88]

With boobs like killswitch i`d listen to him lmao

[EddieO]

I've been racing for 25+ years........30+ national titles to my companies name and built and rebuilt thousands of motors.........and I have NEVER heard of anyone using MILK to break in a motor using the water break in method. Rubbing Alochol, Mineral Spirits, oil, etc sure......MILK? Really. Whoever told ya that must still be laughing to this day.

Later Eddie

[Charlie-III]

DiF......get new brushes for your motor, put them in, lube the bearings/bushings in the motor and run it for ~3 minutes @~3 volts DC.

If it seems OK, stick it in your rig & have fun.


[milk, I've heard a lot of things in the past, NEVER milk though...........]

[EddieO]

Yeah and Charlie was alive when the model T was still in production and RC cars still had strings attached to them.

Later EddieO

Originally Posted by Charlie-III

DiF......get new brushes for your motor, put them in, lube the bearings/bushings in the motor and run it for ~3 minutes @~3 volts DC.

If it seems OK, stick it in your rig & have fun.


[milk, I've heard a lot of things in the past, NEVER milk though...........]

[fred0000]

Originally Posted by EddieO

Yeah and Charlie was alive when the model T was still in production and RC cars still had strings attached to them.

Later EddieO

Charlie know's everything, he's got his nose in about every single thread on RCC.

[Charlie-III]

Originally Posted by EddieO

Yeah and Charlie was alive when the model T was still in production and RC cars still had strings attached to them.

Later EddieO

Not quite. I did start RC cars when you could only get resistor speed controls, the 1st ESC's (a couple years later) were expensive.

Originally Posted by fred0000

Charlie know's everything, he's got his nose in about every single thread on RCC.

No I don't. I have a few sections I tend to frequent, I may read others but don't know enough to add anything worthwhile.
Maybe some don't think I add much worthwhile in the sections I do go.

[Dave_In_Florida]

Thanks for talking me off the ledge guys.

And FYI, I appreciate Charlie's input. He's helped me in a few threads on here and my re-entry into the R/C world. I guess I also have a soft spot for him because I too raced back before ESC's. My first race car was a Tamiya Frog with the wiper arm speed control and a Futaba Magnum Jr. The R/C 10 was a rich mans toy in those days

Thanks again everyone and happy new year!

[Manning]

Yeah, the water break in method wears the brushes very rapidly (obviously). If you do it at all, do it at very low voltage.

I wouldn't have expected the brushes to be worn away in 30 seconds though...

[Dave_In_Florida]

Originally Posted by Manning

I wouldn't have expected the brushes to be worn away in 30 seconds though...

Me either. I may have actually shed a tear when I heard it stop.