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Torque Sensor

kas.lewis

Hello Element14 Community,

 

I am trying to find a torque sensor like seen in this non-English video, any help would be greatly appreciated.

 

Thanks

Kas

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  • 0

    Hi Kas,

     

    Another way of doing this (I'm no expert, so this is just an idea in case it meets your needs) might be to connect up a motor to the thing you're measuring, and control the motor supply until you reach the point that the thing starts turning. (I tried this once, see here: BBB - Super-accurate small motor control with a BeagleBone Black ). That would be good for (say) comparisons of torque, or a rough idea of torque, but of course is not calibrated against anything. But, it is repeatable, so could in theory be calibrated first. The torque should be proportional to current, so could be measured with a multimeter. It would be interesting to try this out on several motors (now I think of it, would also make a good physics experiment for schoolkids), to establish a simple reference we can use as a torque measurement device : ) if it was repeatable across different motors (but it might not be - I don't know how precisely motors would match with each other) and if someone had something to calibrate it against.

  • 0 in reply to shabaz

    The torque calibration at motor stall is easy - you need a pulley on the motor shaft and a piece of cotton (for low torques) and a weight. All you need to do is increase the motor current until it can just lift the weight. Once things are moving it gets much more difficult to estimate the torque actually applied to the load because the mass and inertia of things starts to matter.

     

    MK

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  • 0 in reply to shabaz

    The torque calibration at motor stall is easy - you need a pulley on the motor shaft and a piece of cotton (for low torques) and a weight. All you need to do is increase the motor current until it can just lift the weight. Once things are moving it gets much more difficult to estimate the torque actually applied to the load because the mass and inertia of things starts to matter.

     

    MK

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  • 0 in reply to michaelkellett

    If you're prepared to spend a few thousands you can buy a torque meter or even a full dynamometer from Magtrol or Torquemeters.

     

    I designed the electronics for a torque meter on an aircraft engine that used the wind-up of the shaft as the strain element. The shaft had 2 sets of timing markers that were detected by proximity sensors. The time between rising edges varies with the wind-up of the shaft and hence the torque. Obviously this was measuring high torques, no expense spared, but the whole concept could be scaled down to be small and cheap if you can use, say, a nylon shaft with a couple of timing discs.