Replacement (upgrade) motor for tyre truer

[AndGoliath]

Sorry, late to the party as I just joined. I am just getting out of electric RC racing so I have a bit of experience that applies to the original question.

A brushless motor also requires a controller to sequence the power signals to the three (or more on some motors) poles of the windings to produce the desired speed. Some controllers also require sensor wires connected to the motor to sense the stator position to know when to sequence the power signals. Using RC components you would need a receiver simulator/servo tester to generate a pulse width modulated desired speed signal to the controller which would monitor the motor and send the right voltage sequences to the motor. If you scavenged a brushless motor out of something that had one, you would also have to grab the necessary electronics to control it. Brushed motors are simpler as you just have to apply a voltage and control the speed by the voltage level.

As far as I know, a stock RC brushless motor has less torque, but higher RPM than the old racing brushed open endbell motors. It may be the same as the old silver can closed endbell motors. The new RC cars use lower gearing (more motor rotation per wheel rotation) to account for the difference. The one nice thing about brushless motors is they are really low maintenance. You blow out any crud and oil the bearings (not bushings) periodically. Some people told me they never touched their motors. The commutators wear on brushed ones and you need to oil the bushings more often. When racing we were cleaning the motors every run or so and recutting the commutator every five races. Major pain.

You are on the right track by going with a brushed motor as it will be much simpler to operate. When I scratch-built my own truer I managed to find a motor from an old RC commutator cutter. I believe it is 64 turns and designed to run at 12V since most RC people have 12V power supplies to run their chargers and such. Using a stock motor on a comm cutter meant having to have a four cell NiCd/NiMH pack to run it at 5V to get the right speed. I run it at 10V for my car tires and at 6V for my Fly Truck ones truing the tires for both wheels at the same time.

If you use an open endbell motor, you should put a shield in front of it to protect it from cuttings as someone mentioned previously. If you are really adventurous, the guys with comm truers would swap a stock rotor into a mod motor can since the stock cans used bushings and the mod ones used bearings => less maintenance.

Hopefully this helps. This reminds me I need to go and maintain my truer motor...