Puncher Motors Stalling

Hi! My team was practicing shooting balls with our puncher launcher. We have 4 high speed motors pulling back and releasing the puncher, with no external gear ratio. However, after firing around half the driver load shots, all 4 motors stall and refuse to run. When this occurs, only these 4 launcher motors stall, the others work perfectly fine. When we give these launcher motors a few seconds of rest, we are able to fire for a few more seconds before they stall again. We’ve tried waiting 30 minutes to an hour before trying the same practice run again, but the same stalling problem occurs at around the same time as before: halfway through the balls. Different motor power levels do not affect the stalling. We’ve tried practice runs at both full power and half power, with no difference in the result. We have a regional competition tomorrow and I would be grateful if anyone could promptly give a suggestion for a solution or could direct me to a thread that addresses this problem.


  1. Are all your motor gears lubricated?
  2. Are you using a worn out and/or a linear slider that is not lubricated?
  3. Are your rubber bands/ tubing parallel to each other on both sides?
  4. Do you use an equal amount of tension on both sides of the linear puncher?

Are you using a slip gear to drive the launcher? If so, you could try changing the draw back distance or how many elastics you use. Also, check for any friction on the puncher, especially when it gets to the point where it stops pulling back.

If I were in this situation, I would switch over to 4 high strength motors instead of high speed motors for just this competition.

 We have already switched over to 4 high strength motors to keep our launcher functional.
 I don't think so, we are definitely going to try that.
 The slider is fully lubricated and slides very easily
 Yes, they are parallel to each other.
 I believe this is the same as the previous question, so yes. 

Thanks for the replies, I’ll respond with the status of the launcher after the changes.

Be careful that the point of attachment for your elastics is as close as possible to the line of movement of your slider/puncher. Otherwise the elastics might put a force on your slider that torques the slider and causes it to impart large amounts of friction on it. Also, make sure your gear is not pushing down too hard on the rack (“linear gear”) if that’s what you’re using to pull back on the puncher. If the fit is too tight, the friction can be excessive.

For example, it’s possible to have a slider that moves quite smoothly when the elastics are not attached and the gears are not engaged, etc. But as soon as the elastics and/or gears are in place, the frictional forces could be excessive and, in the case of the gears being too tight, you probably couldn’t detect it by moving things by hand.

Okay, so we lubricated the insides of the motor and switched the motors to high torque. The main change that affected the launcher was the high torque motors I believe, and even with the decreased rate of fire, the high torque motors got us pretty far in the skills challenges that we competed in. Like, #1 ranked in the world pretty far. Anyways, thanks for all the help here, my team (6891 Jackpot) really appreciates the advice given!

What exactly did you do to fix it?