V5 motor issues

So, we just got v5 today, and we put it on our puncher with 2 rubber bands on each side and it could not pull it back. Also, just running with 1 rubberband on each side for like 10 punches the motors started to get hot. If anyone has any solutions it would be very helpful.

Can you post pictures?

This is it it just has 1 v5 motor and not 2 v4.

does it work with 2 vex edr motors?

Are you absolutely sure you don’t have friction popping up in your system somewhere?

I noticed you have one black bearing that appears to have only one screw holding it in place. If so, this could be one source of friction as sometimes a bearing mounted like that can rotate a little out of alignment and put large amounts of friction on the shaft. Also, I notice what appears to be a metal shaft collar very close to the metal housing - I’m guessing you have a thin plastic washer there to avoid metal-on-metal friction?

Last, I would suggest checking to be sure your rubber bands aren’t somehow getting jammed in the mechanism here and there. They look like they are not neatly contained and maybe could get caught in various pinch points during operation. Some kids will put zip ties around their rubber band bundles to help keep them from getting caught in things. Just a thought.

It is most likely due to a difference in internal gearing, thus torque. I am guessing you were using the “standard” 393 motors before (not with “high speed” or “turbo” gears) which rotate the shaft at 100-120 rpm (I saw debates in the forum on exact numbers) and gives you the most torque out of the 3 options. I am also guessing that you received standard production v5 motor which ships with the green planetary gearbox. That gearbox outputs 200 rpm at the shaft @100% power and produces less torque than the red 100 rpm one (36:1 gear reduction vs 18:1 reduction on the green one, so theoretically, almost double the torque). If you know someone with a beta kit, they got the red 100 rpm cartridge, borrow one and test, it will work with 4 rubber bands no problem (maybe more, can’t test, we’re in the same situation as you). Otherwise, wait for Vex to ship the red planetary gear cartridge. In the meantime, you can use a 12t metal pinion to drive the 36t gear and get that extra torque. Our team will just mount an extra motor on the opposite side, just for the time being, just until we get the high torque cartridge and in order to keep the design and the programming changes to a minimum (at least that’s the plan I hear circulating at the moment).

We see the same issue with the torque of the V5 motors. A 393 with 100rpm gear can pull more rubber bands than a V5 with a 200 cart.


these values should be as shipped:
Stall Torque V5=2.1 Nm 393=1.67 Nm

the 200rpm cart V5 should have more torque than the 100rpm 393 gear. So, I think the “smartness” is limiting the current.

We are unable to test any more since we are experience the dead battery issue.

Please post the picture with the one V5.

We figured it out thanks

@Hdemolition46a – And what did you figure out?

I heard on the vex discord that a firmware update or something came out for the batteries.

Yes, have a look at DRow’s post near the bottom of this: