How to determine the approximate torque output of a motor in brake mode

We use brake mode to hold our robot up after we climb, but I’ve never actually seen a list of values for holding torque for motors in brake mode to reference. This seems like it could be a useful thing, even if it’s minimum output approximations.

How would one get this kind of information?

I don’t know of any general measurements. In any case, the gearbox will also provide some braking force beyond multiplying the braking torque. At this point, the best answer is to measure/test it yourself.

Here’s the one data point I can provide:

In general, torque applied by brake mode will be proportional to velocity (i.e., it acts like a dashpot), so there’s probably not a good constant value that you can use. Any holding torque provided at zero velocity is likely due to some miscellaneous stiction, which is pretty inconsistent and hard to predict.

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There was a post about this recently, either @calcmogul or @Oblarg wrote out the calculations.

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