Keeping the claw down

VEX V5 Technical Support
#1

Do any of u guys have advice on keeping the claw down? We don’t wanna reduce rubber bands since that would just reduce strength in throwing. Thanks.

#2

Does your claw flip out or fold back and forth?

#3

We found that just the geometry of the rubber bands will affect this a lot we found that if you make the mounting hole behind and above the pivot point of the arm far enough you can have the rubber bands lay nearly parallel with the arm which will cause it to do nothing at the bottom of the arms swing but as you go up the geometry of the rubber bands change so the rubber bands actually help . This allows you to add as many rubber bands as possible without having problems with keeping the arm down. Hope this helps!

#4

We used to use velcro. Now we use a good rubber band geometry.

#5

Use pid

#6

thanks a lot! I was wondering if your back dumper is a skewed parallel lift or where do u place the rubber bands exactly? thanks

#7

it flips out using rubber bands

#8

Alright thanks. Do you use a skewed parallel lift to place rubber bands or … ?

#9

Put a potentiometer on your lift and add code to a button to get the sensor value of your lift. Then, use PID to make sure that until you press another button the lift stays at that sensor value.

#10

Use a PID controller or a P controller, a P controller would be easier

#11

The problem is not the lift arm not staying down, it is the claw not staying down after it has flipped down at the start off the match.
The solution is to add more rubber bands, and make the rubber bands extend beyond or have a further path of travel than the hinge. Thats how we fixed it.

#12

Are you sure that’s what the OP meant. It doesn’t seem that way.

#13

thats not my problem. my claw stays down fine. it’s the lift

#14

you are correct

#15

A good mount and lift will be your answer

#16

My bad.

#17