Currently, my team is trying to build a scissor lift, and we already have a prototype and a final design down, but we don’t know how to mount it to our robot.
Right now, the lift is powered rotationally with a motor and a larger gear at the first joint.
As seen in one of our prototypes:
We’ve heard from many sources how linear slides are inefficient because of their high friction and bulkiness, but we currently don’t have a way of mounting the lift to our robot. We intend to attach one side directly to the robot using a joint so that it can still rotate, but we need a way for the other side to move closer to the other and rotate as it gets higher.
One of my team members suggested we use a drive shaft and a shaft collar by screwing the other side into the shaft collar and letting it move along the driveshaft linearly while using another joint or a universal joint to give it rotational freedom. Still, even considering our robot’s low weight, I’m not entirely sure this will be strong enough to carry the lift’s load because of our previous experiences with bending low-strength driveshafts.
TL;DR How can we use something other than a linear slide for mounting a scissor lift?
Can’t help you with your question. However, I will recommend looking at some of my threads relating to lifts. From there, look my youtube channel for more detailed videos of lifts.
Both approaches have its pros and cons.
eg. Linear slides - faster in the beginning, easier to build but generally more friction, esp if you are using the linear slides provided by VEX.
China’s gear approach - slower in the beginning, but faster as the lift goes higher (or when the scissor closed up). Harder to build - lesser tolerance for poor build quality.
Try to look out for Wingus and Dingus’s scissor lift. If i remember correctly, it was for Skyrise. It was a very interesting (and effective) approach.
I would recommend making screws with rollers on it like this :
This is very free and the friction is very low. (Make sure you put a bearing on the hole with the roller as it will likely bend without it)
If you want to see our implementation : https://www.youtube.com/watch?v=ScpIO6y_fYw
If you are trying to lift your robot up to the elevation bar, you can actually use your drive wheels as your rollers and that way you dont have to have the hassle of trying to get a linear sliding mechanism down there. I saw team 88909K do this at rumble in the rockies competition.
