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The Brushless Revolution Has Arrived

For the last 18 months I’ve been involved in Remote Control Car Racing (RC) with my son. As it turns out I’m the owner, kind of like Joe Gibbs racing or Andretti Green racing. I’m also the pit boss and pit crew; my son is the celebrity driver.

RC is really a spectacle if you haven’t seen it before. We race 1/10 scale touring cars with electric motors on an indoor asphalt track. After 18 months of racing twice a month we’re finally competitive with the “pros” and others who have been involved in this hobby for a long time. That’s not to say we always win but now we win occasionally but more importantly we are usually in a position to be able to win at the end of the day.

Xray T2 008 touring sedanThe age range of the people at our track goes from kids to people in their 60’s. We race a Xray T2 008 touring car. The learning curve in RC is steep. You have to learn how to assemble your car and then set up your car for the track; such things as over steer, under steer, toe in/out, camber etc. This also requires all manner of tools and equipment.

Anyhow when we first started we started with the less expensive lower end equipment, car chassis, battery packs, chargers, gears etc. Over time as your experience and need for speed increases you start buying better equipment. One of the key items in electric RC car racing is the motor in your car.

Each has unique characteristics that affect the performance of your car. Initially and until recently we were using brushed 27 turn motors; specifically the Trinity CO27 Pro Tweaked Stock Motor. This is a great motor however we never had the acceleration or top end speed of the fast guys at our track. Eventually we learned how the fast guys tweaked and rebuilt their brushed motors by truing the com, replacing brushes, lubricating and otherwise re-building the motor.

The problem with brushed motors is that the brushes maintain contact with the com to complete the electrical circuit. The friction that results from this contact wears the com and the brushes. As the com and brushes wear the performance of the motor drops. So you have to frequently true the com and replace brushes. Unfortunately I was not very good at this aspect of the hobby so our car’s performance usually suffered.

The brushed motor is continually declining in performance. In the course of a 5 minute race the difference between a maintained motor and one with several runs on it is amazing. The guy with a couple runs on his motor doesn’t stand a chance.

Xray T2 008 touring car chassis

We recently upgraded to a Novak 17.5 brushless motor, PROBLEM SOLVED. The brushless motor has no brushes or com. Another purpose of the com is to mechanically flip the electric charge on the armature so that the magnets in the can produce the rotation resulting in the mechanical force that turns the pinion gear against the spur gear.

With a brushless motor there are no brushes or com. The armature contains the magnets instead of the can and the coils are in the can. The flipping of the current is controlled electronically by the speed controller rather than mechanically.

The end result is that with a brushless motor minimal maintenance is required. Generally just blowing dirt off with the air hose and perhaps lubricating the bearing where the axle comes out of can. (where you attach the pinion gear) But more importantly because there is no wearing of the com and brushes the output the motor is consistent run after run assuming you are using the same battery packs. The brushless motors run like they’re brand new out of the box each time. (Of course over time some maintenance and loss of performance will occur but not comparable in any way to a brushed motor.)

With the new brushless motors new comers have motors of equal capabilities as the “pros” who know how to tweak the brushed motors for all they’re worth. You no longer need to have a couple motors rebuilt for race day. Time usually spent on motor maintenance can be spent in car set up or practicing.

After some initial problems, mainly not having the correct gearing we got our Xray geared properly. Using a 90 spur gear and 44 pinion gear with our 1.7 diff we managed to get our gear ratio down to 3.48. (3.50 is recommend by Novak for this motor)

The combination of increasing driver skills and a competitive motor has made all the difference on race. Now instead of settling for finishing a race we’re usually in the top three fighting for pole position for the main and then the top spot of main itself.

So I’m declaring the brushless revolution as here and now. I’m not sure why anybody is still running brushed motors. Some of the “pros” where we race are still using brushed motors. But they’re experts at tweaking the motors. They’re still hanging on to the brushed motor because they think they have an advantage using it. To be honest they did when everyone had brushed motors, but not now. Eventually they’ll have to change to keep up with all of us who have gone brushless. The use of brushless motors in RC is going to increase as the motors get better. At some point the old “pros” will switch when they feel that they don’t have an advantage.

Next increasing performance through better driving and vehicle set up. Its much more fun being competitive!

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June 10, 2008 - Posted by | Uncategorized

1 Comment »

  1. I know first-hand whereof you speak, though I regret the demise of the brush motor. It’s taken both the expertise and romance out of the pit.

    Comment by CJS | June 13, 2008 | Reply


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