Lift sizing

Hi. I already have a lift that works for basic lifting of mobile goals. My bot is currently having issues overheating(wheels) and we are thinking it is in part, center of gravity, and weight. We currently are using all steel, and our current lift is this size: 25 by 5 C-channel on each side of each side of the lift(surrounding), and 20 by 2 C-Channel for the actual lifting part(4 in all). It is a basic 4 bar, and it is seriously heavy. I am wondering how small we can make the 4 bar while still lifting and putting mobile goals onto the platform. I would check myself, but my team only has 3 hours a week for practice so testing is not very possible. I know 2145z(youtube reveal) has a small lift, but I just want to check around. We are also having center of gravity issues, so it would help with that too. Thank you for the help.

it depends how much you want to push on the minimum. the bottom of your goal needs to reach about 12 inches to make it safely over the lip of the platform.
theoretically, with a 4 bar lift you could get about double the arm length as your maximum height. In most cases you don’t get that because the lift hits itself before reaching a perfectly up or down position. So for the sake of theorizing, let’s say your lift can reach 1.5 times the length of its arms, a reasonable assumption. if you need to lift 12 inches, you could then theoretically get away with 16 hole long arms. Now, for various reasons, a 20 hole long lift is probably more desirable than a 16 hole long one, for one it means you have more freedom with what sort of range of motion or lift tower height you can use. And it means you’ll have enough height to place goals on top of other goals, which could be useful.

so your lift is probably pretty good in terms of its dimensions. if you’re finding that the lift is overheating or stalling, check for friction and/or try a stronger gear ratio.

it’s not going to be center of gravity causing your overheating, weight might have something to do with it, but if you’re using 4 or 6 motors on your drive (which you should be), than it’s most likely an issue of friction and/or a too aggressive gear ratio. Posting pictures of your robot can help to diagnose these issues.


Do you have access to aluminium parts?


Technically yes , but it is not enough for anything.

If you want to be competitive, then getting more aluminium parts in will be important.

Technically you can do everything using steel, but most likely you will need to gear down to increase your torque (so that it will prevent overheating). But that means most likely your opponents will reach the goals before you.


25 x 5 is a large piece of steel to use on a lift but you should still be able to make it work.

Check if you have any points of friction in your lift assembly.

  • Are you using bearings between the joints?
  • Any metal rubbing together?
  • Are the joints too tight?
  • What is the gear ratio on the lift? Typically 1:5 or 1:7.
  • How much force does it require to manually raise the lift without a goal?
  • Are you using rubber bands to assist the motors with lifting? Balance the weight of the lift?
  • If you are using multiple motors, are they both operational?
  • Axles straight and no friction?

Most teams use a 25 x1 x 2 and you can even get away with a 1 x 1 on the lower half of the lift.

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The lift works fine. I just hate the weight of it.

How many motors do you use on your drivebase? If you can, use 4 or more. You shouldn’t ever only use two. Even with all steel, your robot probably shouldn’t have that many issues with overheating. I had an all steel bot with 4 motor drive that weighted 23 pounds and only overheated after 8 or so minutes.

I use 2. Overheating is a little issue, but I am also trying to get the center of gravity a bit better. Having a smaller, longer lift will help thst

Use four motors on your drivebase. That will solve that issue. Your center of gravity isn’t going to fix your overheating issue. To also fix your overheating issue, you just need to either add more weight or bring your weight closer to the ground and center of the drivebase. You can do this by adding ballast, mounting your brain and battery closer to the ground, or reducing weight up top.


Sorry. I use 4 motors for my drivebase