Retiming the motors ?

[Salik Syed]

is it legal to retime motors included in the kit... I.E put different guage wire on the insides and stronger magnets etc... and put different winding schemes ? people do this ALOT for model airplanes so that the motor itself produces more torque instead of having a heavy gearbox (although some gearing is still req'd but not as much)

also anyone know about brushless motors? why can't we use those! those are AWESOME

[jonathan lall]

Unfortunately, that's completely illegal. There is very little that can be done to modify motors, and this is explicitly stated in the rules.

[Greg Needel]

johnathan is correct it is against the rules to modify kit motors even though i have always wondered what is involved in wraping 1 drill motor in the oposite direction to counteract the difference going forward and backwards

[Jeff Waegelin]

Just to add the official wording from this year's rulebook:

<R62> The motors in the kit may not be modified except as follows:
• It is acceptable to modify the mounting brackets and/or other structural parts of the motors (output
shaft, housing, etc.) as long as the electrical system is not modified and the integral mechanical
system of the moving parts (bearings, bushings, worm gear output stages, etc.) is not changed or
removed.
• The gearboxes for the Fisher-Price, Drill, and Globe motors are not considered “integral” and may
be separated from the motors. FIRST will not provide replacement for parts that fail due to
modification.
• Caution advised regarding the ½” drill motors: You should not replace the blue wires, however, you
may shorten them such that there is a minimum of 1.5 inches still attached to the motor and solder
heavier gauge wire to their cut ends. Do not attempt to unsolder the blue wires from the brush
housings. The plastic brush support housing will distort if exposed to soldering temperatures and
the alignment of the brushes will be affected, which can permanently degrade motor performance.

Your idea would be considered a modification not included in the list of legal modifications, so it would not be allowed. I suppose it's something you could do for learning purposes in the offseason, but you wouldn't be able to use it on next year's robot.

[greencactus3]

Originally Posted by Salik Syed

also anyone know about brushless motors? why can't we use those! those are AWESOME

brushless motors only spin in one direction. it will be difficult for rookie teams to create a gearbox w/ a reverse to use with brushless motors. and also they tend to be costly.. its like asking why we cant have combalt magnet motors?

[Billfred]

They only spin one way? I could've sworn that you can make them go both ways...although my experience (none whatsoever) may be faulty.

As for price, 540-sized brushless R/C car motors (which are a smidge smaller than Fisher-Price motors, IIRC) are coming waaaaaaay down in price, almost around the cost of buying and maintaining a modified or really good stock motor.

Of course, there's still the problem that they require special speed controllers. IFI might have to go back to the drawing board for that.

[Adam Y.]

They only spin one way? I could've sworn that you can make them go both ways...although my experience (none whatsoever) may be faulty.

You can spin them both ways but you need a special esc to control them. He could be thinking of starter motors which spin in only one directoin. I believe those are brushless also.

[Al Skierkiewicz]

Originally Posted by greencactus3

brushless motors only spin in one direction. it will be difficult for rookie teams to create a gearbox w/ a reverse to use with brushless motors. and also they tend to be costly.. its like asking why we cant have combalt magnet motors?

There are brushless motors that spin in both directions. The capstan motor in your VCR is one (capstan drives the tape and yes it is a nautical term.) A brushless DC motor is simply an AC motor with all the drive electronics inside the case. These motors generally are multiphase (i.e.three phase or more) and are able to produce pretty high torques and very good speed control. The tradeoff is they are usually expensive so they are only used where the precise control is need. You will find many fans in the brushless variety these days. This is more to prevent brush noise (i.e. radio frequency hash) from entering sensitive electronic equipment than the need for precise control.
Everything has a tradeoff, you just need to use the right ones to your advantage.

[datatab1]

Originally Posted by Salik Syed

is it legal to retime motors included in the kit... I.E put different guage wire on the insides and stronger magnets etc... and put different winding schemes ? people do this ALOT for model airplanes so that the motor itself produces more torque instead of having a heavy gearbox (although some gearing is still req'd but not as much)

also anyone know about brushless motors? why can't we use those! those are AWESOME

i am not certain what you are talking about, but you might try building a motor from scratch. not real easy though!!

[greencactus3]

Originally Posted by Salik Syed

is it legal to retime motors included in the kit... I.E put different guage wire on the insides and stronger magnets etc... and put different winding schemes ? people do this ALOT for model airplanes so that the motor itself produces more torque instead of having a heavy gearbox (although some gearing is still req'd but not as much)

retiming a motor is basically turning the brushes a few degrees from centered over the magnets. this is used alot in rc car racing. "modified" motors. stocks are i think advanced 24 degrees. you never want to retard the timing so this is good for applications for forward only. like rc car racing. but unless you want to make a reverse gear transmission, its bad for the motor, as going backwards in an advanced motor=going forward in a retarded motor. depends on how you look at it.
basically its just like the timing of a car. you can time it so its strong at different points of the curve, but if you overdo it the motor doesnt work or wears down REAL fast. here, the brushes and the comm.

[sanddrag]

Originally Posted by datatab1

you might try building a motor from scratch. not real easy though!!

On that topic, it may be easier than you think http://fly.hiwaay.net/~palmer/motor.html I did it.