This week our team made significant progress with manufacturing components for our Most Critical Module, as well as completing our most recent assignment: the Motor Lab.
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| Two identical planetary gear configurations |
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| Assembled 400:1 gear set without motor attached |
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The Motor Lab consisted of assembling a planetary gearbox set with a 25:1 and a 400:1 gear ratio, and testing the performance of each configuration separately. We initially tested the motor alone using a constant voltage from a DC power supply unit, and took measurements of rpm and current, using a tachometer and readings from the power supply unit. We then used a planetary gearbox assembly to create a 25:1 gear ratio, attached it to the motor, and ran more performance tests with the new configuration. After this, we coupled the output shaft of the motor to an aluminum rod, with a Kevlar thread attached to the rod. Weights were tied to the end of the thread, and as the shaft and rod rotated, the thread wrapped around the rod, pulling the weights. This allowed us to test the assembly under different loads. We used metal nuts as weights, and varied the amount of weight for different tests. Once we finished testing our 25:1 gear ratio assembly, we repeated all of our tests using a 400:1 gear ratio. Our team also designed a reinforced "Winch" mechanism that has a frame which helps support the loads placed on the mechanism while in use, and will likely be used in our actual module.
In addition to our Motor Lab, our team has made significant progress with the manufacturing of our Most Critical Module. We have successfully cut out one of our side frames from a quarter-inch acrylic plate using the laser cutter. Although we originally intended to use aluminum for our side frame, we used acrylic due to our constraints on budget and resources, since it is an effective alternate material and should hold up quite well while in use. Also, it looks really cool with our module (the transparent frame shows all the inner workings of our module). We have also nearly machined our mounting disks; all that remains is separating the machined stock into individual disks. We are currently in the process of cutting the other side frame and machining our rod components and frame spacers.
Motor Lab Photos:
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| The basic Motor Lab setup |
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| Measuring the output speed of the motor without gears attached |
"Winch" Mechanism:
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| Winch mechanism will pull a wire upwards |
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| Side view of Winch - the wire will wrap around inner shaft |
