We have a double reverse 6-bar with 6 motors at 1:7 and we’re having issues with stalling, and we were wondering if anyone has any ideas on what could be the issue?
Photo (old photo without intakes, motors have been moved, etc.)
Right now we have 4 motors in the back area with all the gears, and 2 motors at the uprights (all of them are 1:7).
The 4 motors at the back are on a power expander.
In this image the 4 axles pointed in red are powered by axles.
Every single axle in the system is a high-strength axle except for the ones connected to motors. Every axle is supported by bearings.
We have a skyrise claw and arm at the top (not sure how heavy it is… maybe 1-3 lbs?). We also have several crossbars but everything metal on the lift is aluminum.
We have rubberbands spread out over 6 areas (one group for each paralellogram), about enough that it balances the weight when the lift is about 1/3rds to 1/2 way up. They become ineffective when it’s high up though and we think this might be part of the problem
When all the motors are at full power, the lift works fine the first time, then at the second and third times it starts stalling at about halfway up, then after that it doesn’t go up very far.
Things we’ve tried
- checked that all motors are working
- checked that all motors are turning in the right direction
- we have encoders and we also tried slaving them together and enabling pid control but I think this ended up making it slightly worse
(edit: when PID and slaving was enabled, one of the motors kept jerking back and forth (as if it was desperately trying to correct itself but changing it’s mind on which direction it should go))
Any advice or ideas would help a lot!