Lift Problems

Hey guys,
My teams robot has a reverse double four bar with a 2 cube needle intake. It works great except for one thing, we can’t get the rubber bands right. If we put the right amount of rubber bands on with no cubes on, it cant support 2 cubes. When we put the rubber bands on for two cubes, when it at the bottom it pops up, not staying inside of 18x18. Any suggestions? Is there a way to do lift hold code that adjusts for the load of the cubes on the robot? I am using easyc

if you can post some pictures of your robot, I may be able to help you more. It could be a lot of problems, but without seeing it, it is hard give any direction.

In your else stateme yu could have motors set to 15 instead of 0.

Thanks for the suggestion, but that’s not what I’m looking for, I’m trying to see if there is a way to program a lift hold code that actively adjusts to the load, or takes sensor input and tells the motors how much power to output

Oh sorry was confused on what exactly what you were asking.

I don’t think you are going to have very good luck with that. I would suggest maybe putting the mounting points that are pulling the rubber bands, closer together and add more of them. this way, the tension pulling the arm up is closer to the same when up and down.

when rubber band are hyper extended, they pull a lot more. you want the lift aid to be as close to the same when up and when down.

do you have bands on the bottom and top 4 bar layer? could you post your band setup?

I would go with the extra rubber bands, assuming your motors can handle the weight and just figure out a mechanism that hold your lift down and releases when the match starts. Pnumatics, which you are already using, work well for this. Just a pin that slips into a bar on your lift when its all the way down would work

Another option would be to have enough rubber bands for 2 cubes and then have some sort of locking mechanism to keep your robot in size. It can be released based on some sort of movement.

Thanks for the suggestions, my team will test all of these.

I guess they don’t want to post any photos hahahah:D

You could try a pneumatic assisted lift! just incorporate a pneumatic piston attached to the lift and add a function with the lift sequence so it will assist on the way up, but not on the way down.