Help with Scissor "Lifting"

Hello everyone.

Our team has been working hard to build a scissor lift the past few weeks, yet every attempt to produce a working one failed. We’ve tried ungodly gear ratios, an assortment of rubber band positions, and just about everything else you think would make a scissor lift work. The lift simply refuses to go up - at best, it can hold itself up when powered, but we have to lift it to that position.

Does anyone have any advice on how to build a scissor lift? We’ve also included pictures of our current build in case any of you can see something we’re not seeing (see below). Right now we only have a 1:1 gear ratio (which I figure is one of the reasons this build doesn’t work), but multiple robots in past competitions have had a 1:1 scissor lift ratio and worked well.

Any and all feedback is appreciated! Thanks everyone!


Sorry that the pictures are sideways, we accidentally posted this thread incorrectly at first and couldn’t attach the correctly oriented one.

Well 1:1 is a little low on strength. Most scissor lifts I have seen this year are 1:7 or 1:15.

You’re probably going to want 1:7 or 1:15 like Tabor said. I’d also strongly recommend 4 motors on the lift or even higher ratios. That being said, the build quality is quite high so it should work well with better ratios and a bit of tuning.

I’ve personally never seen a scissor run 1:1. Regardless of torque, that seems like too much speed to be controllable. Good luck!

As others have said, it looks really good so far, the biggest issue is probably the gear ratio. Right now it is like if there were no ratio, try to have a small 12 tooth gear rotate around an 84 tooth for 1:7 or compound it even higher.

4 Motors will also help, as well as more elastics/latex tubing, both on the top and bottom, as well as in between if necessary.

There actually already is 4 motors or at least 3 that can be seen at once.

My bad :stuck_out_tongue:
I was on mobile and didn’t look very closely.

I’m viewing on phone, too. But my question is what is the starting angle. The bigger the angle, the easier the lift. Our experience on the slides also is that they seem to work better positioned on the vertically vs. laying flat on the horizontal.

Would it be best if the two motors on each side were using a common shaft? Right now we have one on the bottom of the gear train and one on the top.

Just what ever attaches easiest and stays in spec. I would think having both motors along the outside would give more room for the intake/tray but it depends on your design.

The main thing is to gear it up.