Scissor-Lift

I am currently making a scissor-lift robot, but it can’t lift anything and will move too fast. I need more power, but less speed. I also tried it with gears, but the gears would push apart and turn, not giving and movement.

Here is a picture of corperalchee’s scissor_lift, I hope it helps.
https://vexforum.com/gallery/showimage.php?i=792&c=4

Best tips i can give:
make sure everything is thoroughly stable and tight and yet still free to move
make sure any linear slides are lubricated well
use a gear ratio to get more torque!
Force = Torque
-------
Distance from center of support polygon
So make your rack gear (or whatever is attached to the ‘prongs’ of your scissor lift) as close as possible to the center of your support polygon

if this is not making sense to you read the motion and structure section of the inventors guide
BTW i might be off on a few things, anyone wanna clarify?

Is it legal to lubricate for competition use?

Search the forum there was recently a thread about that.

Maybe these can inspire? One has a few nonVex-possible parts though. The biggest problem with scissors is the starting angle of the lifting members. After they get going, they are really strong. See if you can adjust that beginning torque needed with rubberbands.

https://vexforum.com/gallery/showimage.php?i=825&c=4

https://vexforum.com/gallery/showimage.php?i=873&c=4

[https://vexforum.com/gallery/showimage.php?i=874&c=4

Corpralchees is great too if you have the room.](https://vexforum.com/gallery/showimage.php?i=874&c=4)

I will use these photo’s, thanks. I will need to get more parts first. (I’ll probably get the advance gear and metal kits.)

If you need to, take a look at “The Mammoth” on our website. This was the scissor lift we used last year. It was extremeley reliable and used tank tread and sprockets, a little bit more room, but a whole lot of stability and load it can carry.

https://vexforum.com/gallery/showimage.php?i=873&c=4

[https://vexforum.com/gallery/showimage.php?i=874&c=4

Corpralchees is great too if you have the room.](https://vexforum.com/gallery/showimage.php?i=874&c=4)

What do you think about using pneumatics, and hs motors to power a scissor lift together?
Is this even possible?
What if to make the scissor lift start going you use pneumatics, and motors to lift it once in motion?
Why do scissor lifts shake or wiggle when they lift, raise, or while the robot turns?

What do you think about using pneumatics, and hs motors to power a scissor lift together?

I think the stroke on the pneumatics is too short. I’ve built a few scissor lifts myself for Vex and through experience pneumatics don’t help a whole lot. High strength motors are a much better choice.

What if to make the scissor lift start going you use pneumatics, and motors to lift it once in motion?

Instead of using the pneumatics to start the lift, i would just use rubber bands.

Why do scissor lifts shake or wiggle when they lift, raise, or while the robot turns?

They shake and wiggle when they lift because the connection points have too much wiggle room, especially if you are not using the delrin bearings.

I would say check out the lifts the Chinese teams use (such as the middle school skills champion for Round Up) they have some really fast, really stable scissor lifts. The way they gear it is a bit different from corperalchee’s where the have the 12t gear revolve around an 84t gear (from what i saw at Pan Pacific).

Be careful when you run it for the first time and pay attention to the metal components, its really easy to bend the parts if you don’t brace it using standoffs every couple holes.

Do you have any suggestions to reduce the shakiness on a scissor lift?

Instead of using the pneumatics to start the lift, i would just use rubber bands.
What do you mean by start off the lift?

Do you have any suggestions to reduce the shakiness on a scissor lift?

Instead of using the pneumatics to start the lift, i would just use rubber bands.
What do you mean by start off the lift?

From what I’ve seen the Chinese teams and what we have used for our scissor lifts (good scissor lifts can be heavy by the way) they use the three hole bearing for the connection points with bolts that are about an inch long. For the bars on the lift they use the 1-25 metal bar with aluminum standoffs every two to three holes. This make the bars on the scissor lift rigid, aligned, and keeps it from bending under stress.

In one of your questions you asked if using pneumatics would help start it off? I thought you were asking how would you get the lift started at the hardest part which would be at the beginning (folded up). So i just suggested using rubber bands to aid the motors. I’ll try find some pictures that i looked up last year and post it on your other thread.

Thank you so much. Would aluminum aid the heaviness, and what if I used aluminum c-channel or angle bar? Also what if I don’t put standoffs and do it like this robot?

I will greatly appreciate those pictures!

Well, looks like that scissor lift works pretty well. We used the steel angle for one lift but that was way too heavy. Aluminum is probably the best but there is many ways to do it. As for the pictures sorry, I’m not going to be able to post them for a few days at the least. One of our members has them and hes in St Louis right now so it’s going to take a while. I would suggest trying to find more videos of matches from worlds and Pan pacific.

Oh its alright. I can wait for a few days it’s not like we are gonna start building our gateway lift yet. :wink: This monday my team is gonna start building our drive train, so you got sometime. Were still thinking about what is the best way to reach the 30 inch goals.

Some suggestions i have are
4bar arm (probably what we are going to use)
Continuous loop chain lift (what we used at worlds, if you saw 1103, and HBA the Fire Hazards we all pretty much had the same lift)

Those two and scissor lift are about the best methods I can think of for reaching the 30" goals though I think 4 bar is the simplest. See you guys at Pan and Maui again!

This pneumatic scissor lift is one of my favorites:

http://www.youtube.com/watch?v=VxN8DLBk9fo

It was posted quite a while ago by 2438 | 'Iobotics

I asked one of the members on the team if he had pictures. he said what we had was posted on our website. So i checked it and unfortunately it did not have any pictures. Sorry about that. However the diagrams people have posted show exactly how the chinese made their scissor lifts. Good luck!