Motor_Testing_Timing

The last couple of days we’ve been testing our motors more intensely. The metalworker Peter delivered a very nice job: a slim but sturdy housing for the motor that will move the big chute. As soon as we got it in our hands, we suspended it with a chute and watched with wonder how the fabric reacted to the movement and airflow. Take a sneak peak!
Watch the first motor test, click here!

This test was done manually but after waiting a few days for some new parts for the motor control, we could test it more thoroughly. We weren’t sure how the power source would react to sudden changes in direction. First, we tested it without any housing and even without any weight strapped to the motor; the power source overloaded as soon as we turned the direction the other way. We read that a lead-acid battery connected to the circuit would do the trick, and it did! The peaks get nominalized by the battery so that the power supply doesn’t need to take care of this and won’t overload.

With this knowledge we connected the motor controller to MAX MSP that linked it with one of our wearables. Click here to see a chute react to the movement of the wearable.

There is a lot to think about when it comes to motors. Besides power distribution, torque and amperage overload, we had to calculate how many revolutions we want to have for the chute. Since the motor is not strong enough to carry the weight of the chute, we had to transfer the spinning motion to another system. The motor we have has an RPM of 240, way too fast for a chute, so we had to scale it back to a manageable RPM. With a timing belt and toothed gears in a configuration of around 5:1 we got the speed that we needed so that we could turn the chute slowly without loosing too much torque and give it a quick spin if we need to.

Timing turned out to be very important for the last test we did today. A smaller cone shaped chute will get a falling and hoisting mechanism. We needed to test if MAX MSP would be accurate enough to drop and hoist quickly without too much difference in the start and endpoint. click here to see the video of the latest test.
For the sake of the motor we tested it with an old drill head which has recoil protection, so that, when the weight would hit the endpoint, it wouldn’t destroy the motor.
But as you might have noticed, it didn’t hit the endpoint. It looks like the code is accurate enough to stop and start at exactly the right spot. All is going well!

 

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