Output Torque of CIMple Box with 2 CIMS

[Whippet]

Hey guys!

My team is wondering about the maximum output torque of a CIMple box from last year's kit. We are considering using it as a winch to lift our robot, and we really can't afford to burn out our motors this late in the game. Any help would be appreciated!

[Ether]

Originally Posted by Whippet

Hey guys!

My team is wondering about the maximum output torque of a CIMple box from last year's kit. We are considering using it as a winch to lift our robot, and we really can't afford to burn out our motors this late in the game. Any help would be appreciated!

How much torque do you need, and for how long? That's what will determine if you're going to burn out the motors.

[Whippet]

We need it to output ∼ 200 lb-in for intervals at around 10 seconds, three times. That should be the only time that the gearbox is pulling the weight of the robot.

[Richard Wallace]

The CIMPle Box (am-0734) has 4.67:1 speed reduction ratio.

A CIM at maximum power will deliver a little more that 1.1 Newton-meter (10 lbf-in) torque at about 2600 RPM, running from 12V. A little while ago I posted some lab measurements of CIM temperature rise at maximum power.

To get 200 lbf-in at your winch, you will need to gear down the CIMPle Box output. To avoid working the CIM past its peak power point, you should use about 5:1 reduction after the gearbox.

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Edit: using two CIMs you will need less reduction after the gearbox, maybe 2.5:1 will be OK. Push it to 2:1 if you feel lucky. But as Ether said above, without reduction after the gearbox, it's not happening.

[yash101]

Our robot also has a winch. We are using a CIMple box too and there is only one CIM. It is slow, but it winches up out 110 pound robot with quite some thrust. I think you might only need one. However, you were saying that there is 200 pounds needed to be lifted, then two CIMs would probably be needed. It should give enough torque.