Hand-Wound Brushless Motors Revive Grounded Quad

You’re happily FPVing through the wild blue yonder, dodging and jinking through the obstacles of your favorite quadcopter racing course. You get a shade too close to a branch and suddenly the picture in your goggles gets the shakes and your bird hits the dirt. Then you smell the smoke and you know what happened – a broken blade put a motor off-balance and burned out a winding in the stator.

What to do? A sensible pilot might send the quad to the healing bench for a motor replacement. ButĀ [BRADtheRipper] prefers to take the opportunity to rewind his burned-out brushless motors by hand, despite the fact that new ones costs all of five bucks. There’s some madness to his method, which he demonstrates in the video below, but there’s also some justification for the effort. [Brad]’s coil transplant recipient, a 2205 racing motor, was originally wound with doubled 28AWG magnet wire of unknown provenance. He chose to rewind it with high-quality 25AWG enameled wire, giving almost theĀ same ampacity in a single, easier to handle and less fragile conductor. Plus, by varying the number of turns on each pole of the stator, he’s able to alter the motor’s performance.

In all, there are a bunch of nice tricks in here to file away for a rainy day. If you need to get up to speed on BLDC motor basics, check out this primer. Or you may just want to start 3D printing your own BLDC motors.

Continue reading “Hand-Wound Brushless Motors Revive Grounded Quad”

Build your own vertical axis wind turbine

You can build a copy of this vertical wind turbine in a weekend and it won’t cost you all that much. Applied Sciences developed the hardware and they’re sharing all for the build details. You will be taken through every part of the build starting with the fin assembly which is made from stove-pipe material. This is a perfect raw material because it is already curved and suited for aerodynamic use in much the same way that PVC pipe is for making fins and we would expect it to be a bit lighter in weight. You will also need to turn your own coils when assembling the stator. This particular build process uses nine coils embedded in fiberglass. They remain stationary while two different discs, each containing a dozen rare earth magnets, rotate in close proximity to induce a current. It outputs three-phase AC current which can be turned to DC using a bridge rectifier and then further regulated for storage in batteries.

[Thanks Miguel]