Motor weakens

Ok so our lift has a 1 motor 100 rpm lift geared to 1:7 that also banded but the issue is after like 2-3 times when we lift the goals on the platforms it just weakens and it can only lift it half way. Any solutions?

This could be because the motor is overheating. I believe motors start to loose power at 50C.

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So what it sounds like is happening is that your motor is overheating. This is likely what is happening if the lift works a few times but after using it for a while ceases to lift.

Here is how to check if this is the case:

  1. Note the motor port that the motor in question is using.
  2. While the program is running, disconnect and reconnect another motor.
  3. A screen should show up that says “Motor X disconnected.” When you see this, click the “View Log” button.
  4. Scroll up in the event log and look for the motor number of your lift. If it is overheating you should see a message that says “Motor X over temperature level X” Any motors over level 2 or 3 are likely being throttled by the brain to prevent them from being damaged.

If you have determined that the motor is overheating, here are some steps to reduce the load:
Firstly, Look for friction on the lift. Disconnect the motor from the lift (Either unscrew it or pull the axle out a half-inch so that it stays together but no longer engages with the motor.)
Lift the lift with a goal in it and see how much force it takes to lift. Can you make the lift lighter? Can you reduce the length to give the motor increased leverage? If the weight isn’t the issue, it could be excess friction on some part of the lift.

Possible sources of friction:

  1. Misaligned axles. If your robot has some misaligned hopes or warped pieces, the bearings could be misaligned and causing excess friction
  2. High strength Axles. If you use HS axles, make certain that the drilled-out holes are big enough that the metal never touches the axle.
  3. Unnecessary complexity. Make sure that you don’t have any extra systems on your robot that could be causing friction. Ex: more gears than necessary.
  4. Bearings. I apologize if this is obvious, but make sure you use bearings whenever you have anything that moves. Any joint or axle needs bearings on all C channels.

This is as much general advice as I have. If you still have issues, feel free to send pictures of your lift and I would be happy to look at it in more detail and give more detailed ideas.

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one motor should be able to lift a goal at 1:7 100 rpm.

pictures of this lift would be helpful in determining if there is an obvious source of friction in the build, which is likely the cause for the motor overheating.

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Theoretically yes it should work, but when put in the real world it puts a lot of strain on the motor when you use it over and over again, also if you reduce the weight of the lift it should run better

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100 1:7 is really powerful, definitely powerful enough to lift a goal, especially if it’s banded.
@rathul_2068, can you send pictures of the lift? And make sure that the rubber bands are on the right way, so they help the lift instead of fighting it.

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I will send a picture tomorrow since I have robotics that day

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Right now this is the only picture of the lift but you can’t tell very wellimage

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Maybe I’m wrong but from that picture, it looks a bit like the rubber bands on each side of the 4 bar are different? Is this the case? Is there a reason for this?

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lol its cuz its all made of steel

edit: actually tho check if your screw joints are over tightened and feel around the lift when it moves to try to identify where friction could be. I couldn’t tell you from that picture but it is likely a combination of friction and the fact that it appears your 4 moving bars are made of steel. Just looking at your lift I would expect motor burn to happen regularly at around 5-8 minutes of use

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Motors weak
Robot’s heavy
Wires are spaghetti

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A lift of this size should work well, whatever material it is made out of. Our org only started to buy aluminum parts recently so I have a similar (but larger) 4 bar made out of steel. It is powered by one 100rpm motor geared 1:7.

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Try adding Teflon washers so it’s not metal on metal. That can cause a lot of friction

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Both things that you circled don’t seem to need teflon washers. The top one looks like a screw and would only need a washer if it was acting as a screw joint(on the flat side of the kepts nut).

The bottom one looks like a end of a screw joint and doesn’t need a washer because there is a bearing flat there.

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It seems likely you’d be interested in using Motor.temperature(percent) to display how things are going. This post explains how power supplied to a motor is intentionally reduced by the system according to temperature:

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