Brushes wear out very fast HH motor

[mtgrizzlymn]

Why do the brushs wear so quickly in the HH motor it's a 27 turn and after prob 2 hours total run Time they are gone. Old racing days brushes lasted a long time.

[DRTMI]

To get the torque out of the motor, a very soft brush is used. At the same time, for improved drag brake, a very heavy spring is used. Both of these together will increase the rate of brush wear. In my old racing days, my brushes would only last for 4, 4 minute heats, and 2, 4 minute mains. This was on 6 cell nicd (showing my age here) packs with 18 turn and lower motors and fairly hard brushes. Of course the trade off with using a harder brush, if I am remembering correctly, is increased comm wear. Also, higher battery voltage will wear brushes faster.

[Shinjari]

Wow! I've run easily 40+ hours on my HH 55t hand wounds and machine wounds and they show very little wear. DOnt think I'm running the Holmes Hold on my BRXL's and have roughly 60% drag brake.

[mtgrizzlymn]

I raced in your day to it seems, but I sure dont remember changing them that often I would use one heavy and one light spring then cut my own brushes to try to get more rims it worked. I noticed John puts grooves in his brush but curious if its a special compound in brush or just normal soft brush I have tons of new ones from racing.im also runnining 11.1 volts

[Arctic Fire]

I think the question should be why does a 27t motor in an SCX-10 wear so quickly.

[Manning]

Water will radically accelerate brush wear.

To put it in a different perspective, 2 hours of run time would be equivalent to about 6 race days.

Yes, I raced in the NiCad days.

[JohnRobHolmes]

Try advancing the timing to 12 degrees and using a softer spring to increase your wear. Below 7 ounce springs tend to arc, stay above that rate. Stay away from water too. If you have a BRXL turn off hold mode. If you are using 3s lipo, realize you are putting almost double the voltage to your motor as compared to racing days. If you are at zero timing, add some for a happy motor.


The lower the motor resistance, the faster a brush will wear on a given voltage. 27t wears faster than 35t, 55t slower than 45t. Handwounds wear faster than machine wounds. 55t machine wound motors can be run for years with just a little care and clean running.


The biggest wear factor is all about the person on the throttle. I have seen kids wear down brushes in 30 minutes on my rig when I just got done putting 10 hours through a set. Forward to reverse action eats them fast, and is something you would never come across in racing use/abuse.