Roller Four bar slams a lot

Our robot has a fourbar made of half C’s on top of our dr4b, and we notice that when it goes forward and back to translate the cone, it slams down and causes our lift to wobble a lot. How should we prevent this?

You could try automatically slowing down the four bar when it is very close to an end using a potentiometer or something.

In addition to what @The Electrobotz said you could also consider using gearing to control the mechanism, but im not sure what you exact situation is. Pics might help

Use rubber bands to slow it down.

use rubber bands and or more of a torque gear ratio

Well i geared it 1:3 HS and while its quite a bit slower, stability is more important than speed imo.