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Prototype Repair, Working Power Supply

A project log for EVPR: Electric Variable Pitch Rotor

An electrically actuated variable pitch rotor with a wireless interface

peter-mccloudPeter McCloud 07/24/2017 at 01:260 Comments

While it's impossible to know the exact sequence of failures during the previous test, it's clear that losing power was a contributing factor. Using small gauge solid wires with soldered connections and standard servo connectors was a poor choice considering the high vibration environments.

The power supply board was re-worked afterwards to come up with a better design. The connectors for the servos and the batteries are all screw terminals now and all of the solid core wires have been eliminated. The image below shows the power supply board with the screw terminals.

Another test was conducted, this time with just the electronics powered and the blades and axle removed (The replacement parts aren't ready quite yet, but I wouldn't have put them on for this test anyways). 

The test was a success. The start-up and shut-down sequence was conducted a total of four times and the electronics never lost power. I should have done a test similar to test before attaching the blades in the first place, which would have eliminated some of the re-work I'm having to do now.

The new blades are nearly complete and a spare set is in-work to ensure that if there is another failure, the project won't get slowed down. Below is the two epoxied blades and the cores for two more space blades.

One other design change in the works is the addition of thrust bearings. The hardware for that will get here tomorrow and then the blades will be ready to be installed with the thrust bearings. If everything goes smoothly, the full prototype will be assembled again and ready for testing by the end of the week.

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