Gear Ratio help VEX IQ

We built our robot and realized we have 7 motors instead of 6 duh. We are thinking of only using one motor for our arm but are concerned that it may not have enough torque. Any suggestions on a gear ratio build that would give the arm enough torque to lift 2 risers?


Hi @Nickyg529!

Can you give us a bit more info regarding your robot? Including perhaps pictures? Thanks!


I bet for ur arm u can use a 64 teeth gear ten a 12 tooth gear’

  1. That’s pretty extreme ratio
    A. It’s going to create a lot of speed if the 64 tooth is the driven gear
    B. Or it’s going to be very slow if the 12 tooth is driven.
  2. They apparently have it working with two motors, but that’s all we know.
    A. Is it a simple shoulder lift? The a 12:48 should be more than enough.
    B. If it’s a long arm, more torque is needed, what’s the size of the arm.
    C. 4 bar linkage? What’s the other dimensions?

@Sharky_do, lots of unknowns that would be good to know beforehand. Just flinging ratio numbers out there isn’t helpful. And remember they can do stacked gears to fine tune their arm.


If it’s really needed, 12:64 isn’t a terribly slow ratio, stacking another one is a little rough but overall the one connection is no problem. But I agree that a 12:48 should work pretty good in the end depending on how heavy the arms are.

1 Like

I’m sorry, I just gotta say it.

It’s 60 tooth, not 64 tooth.


Obviously, there is more to this question then I thought. I will gather more information and repost the question. Thnak you all for your help.


Unless your team is already using rubber bands to assist, have a look at the Rise, Clutch and Stretch for your team to get some ideas on how to store energy and reuse to help lift.