Suggestion: New Motor??

Would there be any possible way to make a motor that has any more torque than the current ones? We have maxed out our robot on motors/ servos using 4 solely on a gear system. We have so many great ideas to add on to our robot, but no more motors to spare.

I believe there is (was?) a larger motor in the works with double the torque at the same 100rpm?

Well, I guess you could open up the motor can, and rewind the armature. Putting on more turns of wire, to a certain extent, will increase torque. However it will decrease speed, so use prudence when deciding how many turns to put on.

What good would that do? You could just gear for more torque.

For VEX Competition, no. You are limited to a total of ten motors and servos, and limited to using the VEX motors as originally designed. Modifying the motor would make it illegal for competition.

For your own purposes, however… go nuts. Hook up a speed controller and a much, much larger gearmotor to achieve your goals.

But if you want to compete on the VEX playing field, you have to work within the parameters laid out in the rule book.

It sounds like you’re doing a competition, and I think dt is right on this one. I mean, my partner team wishes that they could just use one more motors to make a mechanism that would really help them, but I mean everyone has to abide by the rules.

I am part of the Clean Sweep Competition (and we qualified for Worlds in October yay!) but i saw a post from who knows where about a prototype design of a new VEX motor. Just wondering if it was true or the hopes of a fellow nerd.

It was mentioned on this thread, on this very same forum (see post#2).

  • Dean

Oh, well what do you know! Haha, I didnt see this thread before. Anyone know when it will be released?

Looks like it’ll be available first at the World Championships in Dallas, and then available via the regular on-line store sometime after that. See this thread for details. Here is the actual product page.

You get a 60% torque increase OR a 60% speed increase. It includes changeable gears so you can configure it either way. Also, since the gearing is metal, no clutch is required.


  • Dean

Interesting. Looking at the datasheet, the standard motor draws .14 amps at free speed, but the two wire motor draws .15 amps free speed, but with 60% more power. Either the standard motors were super inefficient or there was mistake in the datasheet. Those amp ratings are extermely similar while the power ratings are… drastic.

I expect the no-load power draw is more a function of the friction of the output gearing, so you can’t really compare them directly unless you know exactly how much work is being done to overcome this friction.

Also, the classic “3 wire” motor power rating includes the integrated controller, which the new 393 motor probably do not.


  • Dean

those motors can only be used with the new cortex microcontroller
so we cant just grab a few and stick 'em on >.<
hope we have enough funding for the stronger motors next year
esp if next years competition involves more robot to robot contact

Look more closely at the store - you can use these new controller dongles to use them on the 3-pin motor ports.

  • Dean

i thought in earlier posts someone said that the new motors are only compatible with the cortex
$10 for A (singular) pwm converter cable

Yeah, pretty expensive… _

I have a strange sense of deja vu…
The price of one of the new motors: $19.99
The price of an external controller:$9.99
Price of a 3-wire motor: $19.99
Difference: $9.99
Percentage difference in price: $9.99/$19.99 = 49.97%
Claimed difference in mechanical power: 60%

How is that out of line with current pricing?


Seems perfectly reasonable to me. I think that when you have an audience of engineers (such as the Vex forum members) it is very easy for them to see the cost of the parts as the value of something, since they could probably put it together themselves.

For a product like this, I suspect the business costs (insurance, utilities, facilities lease, R&D, tooling, yield/return allowance, etc) are greater than the actual materials cost. Not to mention the fact that IFI is a for-profit business that needs to make a little extra coin on each sale to keep growing and bringing us cool new toys!


  • Dean

So can you use these in Dallas?? Seems like allowing this in Dallas would send a lot of teams scrambling. Seems a bit unfair to change things now…I don’t know

I would have to agree with bradley4kevin.