Vex Robotics Lift Issues

Hello everyone, I am having an issue with one of the two lifts on my robot. The lift that does is suppose to lift up nuetral mobile goals does not seem to lift. I am using two motors - geared internally for torque and slightly geared externally for torque - and my lift cannot lift the mobile goal two inches off the ground. Additionally, the motors are programmed at like 800% power. With my Vex Competition this Saturday is there anyway that I could ressolve this issue quickly.

sending us pictures is likely the only way for us to diagnose the problem.

But I will say

will not be doing anything.

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Okay just give me one moment
I can send some pictures of the lift, there not that good but my robot is at school so this is what I got atm

These are the two pictures I got I hope this might help, the robot is basically complete but the lift looks like this atm

What types of cartridges are in the Tower Motors?

They are red cartridges. The weird thing is I used the same gearing structure for my mobile goal lift and it can pick up mobile goals just fine, but for my normal lift it cannot lift a mobile goal at all.

Your lift is geared for speed, not torque. Try switching the 36 and 60 tooth gears, and if that’s still not enough, switch the 36 tooth gear to a 12 tooth gear.

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Couple of questions.

  1. Are your motors direct driving your lift? - If yes, then this may be your problem you need a ratio geared for torque so maybe a 36 to 60, but the better option would be 12 to 60.

  2. If 1. is no then what gear ratio do you have? From your pictures it appears that there is a 60 or 72 tooth gear below a 36 tooth gear which would be a ratio for speed if the motor is connected to the larger gear. Which would also explain your problem because a ratio geared toward speed is not one made for lifting mogos.

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You guys are completely correct, I am just an idiot. I did not gear the lift to torque but instead to speed. Now I have to ask a question. Would it be wortwhile - in your guys opinion - for me to fix this lift before my competition this Saturday, or should I just spend the majority of the time practicing.

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fix the lift. it’s super easy all you have to do is switch the gears, that’s it. its a probably a 5 minute job to switch the gears, it might take 30 minutes to and hour to complete the lift but it is definitely worth it.

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Okay i will def try it out, i’ll keep you in the loop. I just gotta ask one more question. Do y’all think a gear ratio were I have a 64 tooth gear to a 36 tooth gear would work. Or would it have to be a 64 tooth gear to a 12 tooth gear

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I would recommend the 64 to 12 gear. I think it’ll have the right combination of speed and torque that you need to pick up the goals. It approximately equals 18.75 rpm.

It’s also a little more compact than the other option (64 to 36), should you need more space for additional mechanisms later on.

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Okay, I am just afraid of one thing. My back lift has to rotate about 180 degrees because it starts over my conveyor belt and then flips out during auton. Do you think this new gear ratio could prevent my lift from flipping out

idk if this makes sense, let me know

I don’t think so, if you don’t have any problems with your current lift then a smaller footprint with the 12t gear wouldn’t have any problems either.

The best option would be to build it and see if everything still works.

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Okay thank you guys so much, you guys are a lifesaver I will definetley keep y’all in the loop

For tourqe you need the motor spinning the small gear so it goes like this, small gear to large gear

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36 to 64 would work but 12 to 64 would be better and would put less stress on the motors.

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Well given its kinda an important part of your robot I would fix it. It shouldn’t take too long and it will be a good addition to your design.

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