So we have been building our robot with V5 motors and we have continuously run into the problem of it overheating (especially on the lift). We have two V5 motors on the lift with normal gearing. It works at the beginning, but after a while it stops being able to lift up. We tried to use canned air but it still hasn’t worked. Any advice?
Can you post pictures of your lift? It sounds like a different problem than just the motors. Maybe no “neutral buoyancy” (using elastics)? Maybe lots of friction? Maybe something else? It’s hard to tell without being able to look.
It looks like your elastic get nearly loose at the top, which you actually still want them to provide some noticeable force (though not nearly as much as you need halfway up) to counteract gravity. I would adjust that. You want the elastics to be just barely not strong enough to start moving the lift upward on their own when it’s fully down, and you want them to be strong enough the entire way that they can prevent if from lowering at any point. Do your elastics do this? They seem insufficient. The common technique to have enough force higher up and not too much lower down is to make triangular connections with the elastics.
Also, you have a lot of excess metal. First, there are some c-channels that extend further than actually accomplishes anything. Second you could narrow down nearly every piece in the lift to make in an angle instead of a c-channel. You could cut the weight of the lift itself nearly in half with these changes. Since it won’t change the motors and the claw, and since those are further out, I’ll estimate you could cut the torque requirement by 20% or so.
I might look at the gearing. I can’t see what gearboxes you’re using, but with a 1:5 ratio and 200RPM gearboxes this thing’s top speed would be a blistering 40RPM. Given that the arm only looks to swing about 90 degrees, that’s a lift time of 3/8ths of a second at full speed. It probably isn’t running at full speed, though. I’d try changing to 100RPM gearboxes or reducing the main ratio to 1:7. I think you’re just running your motors too close to stall speed. These motors like to be spinning fast, and your motors will never have a chance to go fast, so they will do all their operation in the very slow and hot performance band just above stall.