Goliath Spring 2018 – Mock Up Motor Under Load
By: Ryan Nguyen (MST Engineer)
Verified By: Ernie Trujillo (Project Manager)
Approved By: Miguel Garcia (Quality Assurance)
Test Description
A mock-up motor under load test was performed to determine how much current the Goliath’s motors would draw while being put on mock loads, which were weights. Since the amp-meter has a large resistance, direct current measurement was not possible, as only a very small amount could flow through and the motors didn’t even turn. In place, a voltage measurement was taken over a 100-ohm resistor to determine the current of the motors. The motors would lift the weight, hung on a gear, and the highest voltage is recorded. Testing stopped when the weight reached 80 grams, any more than that the motors would not move. 80 grams per motor is quite good as the Goliath robot would probably weigh between 150 – 200 grams. The test also suggested that the maximum current pull from motors are about 35 mA each, which is useful for the power budget.
Figure 1 – Table displaying voltage and current values of both motors at varying loads.
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