Ok your a lot father north than I thought. I do know of a few decent launch sights nearby for a paramotor.
I’m currently planning on training with Dell as he has agreed to train me for free when there is an an empty slot. After that I may go get additional instruction from a different paragliding instructor that could teach more on the wind conditions of the mountains.
Here is my short opinion of Dell I have only met him 2 or 3 times. In fact he helped me thrust test the Open PPG paramotor setup I have been working on. He is a very honest person from what I have seen of him and he truly says what he believes. But often his very strong beliefs turn to criticizing others. He also has a different personality from others. Many people can’t handle his personality, but it doesn’t bother me.
With or without the reputation, Dell is an incredible pilot and I believe he has one of the better training programs so I will happily take what I can get.
No kidding… I had barely heard of the guy until his name popped up on this board. I went down a serious Google hole reading about him the other night, and none of it was even paraglider-related!
I had an ESC shutdown on me mid flight. I had to land and reboot then it ran fine for a few minutes then did it again.
Later I discovered that the motor controlled by that ESC was harder to turn than the other motors. I took the motor apart and found one of the bearings was gummed up and not spinning free so I ordered some replacement bearings. When I reassembled it with the new bearings it still had the same problem.
While turning the motor by hand it wanted to stop about every 1/2 inch of rotation (the distance between the magnets). It didn’t feel like a physical obstruction but like a magnetic field was stopping it. The other three motors don’t feel like that. Turning it by hand felt like a motor with fewer stators which wants to stop as the magnets pass each stator. These motors have so many magnets and stators that they don’t normally feel like that.
Under power the motor had a loud whine that I didn’t notice while flying. After a minute of power at low throttle without a load (no prop) the motor got quite warm and the lead wires got hot.
I noticed a black wire inside the motor. There was a short circuit across a phase where a wire heading to a lead made contact with a coil. Note, the wires inside of motors are not bare wire. They are coated with an epoxy coating. Not sure what caused the epoxy insulation to come off the wire to allow the copper to make contact and create a short (maybe vibration or a piece of debris). The short circuit caused just the one wire to get hot and blacken the epoxy coating:
I pulled that wire away from the coils and suddenly my motor spun free again while turning it by hand and no longer wanted to hesitate as the magnets passed the stators.
At this point I decided fix the epoxy coating by brushing any suspect area with silicone modified conformal coating. That stuff is made for waterproofing circuit boards. I generously brushed two coats over any suspect area. It glows purple in UV light so when I took it outside to test it I could see where the coating was applied:
I was only able to repair the coating because the fried wire was loose and I was able to pull it away from the other wires. If a wire wrapped tight around a stator got fried you wouldn’t be able to get conformal coating between the wraps.
I ran it up to full throttle and it runs smooth and didn’t get hot. I might take it for a flight later today if the weather is good.
Awesome write up. Thank you. Good thing to watch out for. I suspect the wires that are still tightly wrapped would be unlikely to have any insulation issues due to vibration. That this wire was loose is probably what caused the wear on the insulation. Just guessing here. How many hours are on your motors?
Now commencing a close inspection of my motors for loose wires.
To be clear, the fried wire didn’t become loose. All of the wires running around the perimeter are loose enough to manipulate and to be able to coat with the conformal coating. So I’m glad it was one of those wires because I was able to fix it. I don’t know what caused the short. It may have been due to vibration but I probably have over 150 hours on it in the 3 years.
That’s interesting indeed. Your motors are a bit different than mine. All of the wires on mine have black plastic coating on top of the epoxy where they run around the circumference to the exit. Also they are all very solidly glued in place. Picking a bit with my fingernail nothing moves except this one small length (avoiding the word short ) in one of the four motors. That bit flexes slightly but isn’t what I would call loose.
A running upgrade in the production?
I have only about 100 flights on mine so less than 30 hours. @150 hours you must have over 400 flights/ battery cycles. How are the batteries holding up?
Good news! I flew yesterday for the first time since I fixed the short in my motor and I didn’t have any issues. I was worried that my ESC got damaged from the short in the motor but it lasted 25 minutes without shutting down.
Here is an air to air picture that my friend took of me flying over my neighborhood:
I am just fitting the rails for the x4 designed by gliderpilot. Just a quick question for him or others: how tight should I go with the cable ties around the lipos? I am worried if they are too tight then they may cut into the battery and damage it. Maybe put some duck tape underneath??
Another point to help others… I didn’t have a suitable riveter so I used cross head countersunk m4 bolts which seem to work well. The heads have to be almost sunk right into the rail base otherwise the sliders will not slide over them due to the cable tie reducing clearance. I also had to expand x and y dimensions on the rails by 6% otherwise it was too tight. (I used PLA). I used locking m4 nuts. I spaced the rails in a little (115cm) because I was worried they would impede the harness straps. (this may not be the case).
The batteries have a really thin aluminum plate on the front and back of them which helps to protect them so I put the zip ties on fairly tight. If you use a good quality foam tape on the sliders then the zip ties won’t need to be as tight.
PLA will melt in a hot car so be aware of that. Did you print the parts standing on end so that you aren’t relying on layer adhesion to hold the weight of the batteries? PETG has better layer adhesion than PLA but even with PETG I printed the parts on end.