I have a scissor lift using rack gearbox brackets attached to inner acetal slide trucks. The slide trucks go inside a linear slide and go back and forth as the scissor lift moves, you know, like any other scissor lift.
I noticed while driving that the lift could go up with ease, but had a lot of trouble coming back down. The lift is 1:7 and evenly rubber banded. So, I took off the motors and rubber bands. Sure enough, I could pick up the lift fine, but found the slides to have a lot of friction going back down.
Has anyone used inner acetal slides in the past and do you know how I might go about reducing their friciton?
The simple answer is that you can’t. Honestly, monkeys could make better linear slides, and all good teams try to stay away from using them whenever possible. I suggest to use other vex parts to make linear slides, such as 12" shafts.
Try silicon lubricant. You can use it “moderately”
I would suggest taking off some rubber bands. If it can go up easier than going down it likely means that you have too many rubber bands pulling it up but resisting any downward force.
If you have time, it isn’t too hard to make custom linear slides like the ones in this video:
Custom linear slides often are more bulky than the VEX ones though
Make sure (without any metal attached) the pieces move very freely on the linear slide with little to no force. If it doesn’t, get new metal slides and green slide piece, or add some lubricant