Craig's Sling 4 Build Log
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Friday, June 2, 2023
Monday, January 23, 2023
Further debugging and it looked like the pitch motor itself had failed. Voltage applied directly to the motor did not move the motor at all.
Turns out that the motors in Airmaster props older than a year (give or take) have a design prone to open circuit failures. So much so that they completely redesigned the motor and there are formal instructions for replacing the motor. The new motor is more robust and faster in changing the pitch too.
My new pitch motor arrives on Wednesday (thankfully covered under warranty). I'll have to update the controller parameters with this change and I've already got that file. I'll also update the controller firmware while I'm at it.
Photos show the disassembly of the hub to remove the pitch motor itself, which I'm holding in the last photo.
Sunday, December 25, 2022
Monday, December 19, 2022
I don't have any pictures, but I wanted to pass along how my last flight went. This was the first flight since installing the preheater and the back seat seal and both worked like a champ.
The day was quite cold (upper 20sF (about -2.7C)), so I had turned on the preheater the night before. On startup, the oil temp was almost instantly about 90F and ran smoothly from the first crank. My experience on prior cold starts was that it would run pretty roughly for the first few minutes. Not this time at all. Smooth as silk.
Up in the air, I found the cabin quite comfortably warm. That's never happened before on cold days. The draft from the back seat was quite strong and as far as I could tell from the front seat, that was totally gone.
Big wins for winter flying!
Monday, December 5, 2022
Friday, November 11, 2022
I got my shipment of the new brush (actually I ordered 3 in case of future failures) from New Zealand. 3 days door-to-door. Not bad.
The assembly before starting. I had already desoldered and removed the wire from the center pad.
Sunday, November 6, 2022
On my last couple of flights, I saw a failure indication on the Airmaster prop controller. 3 Flashing red lights, which means there's an open circuit to the prop. It was intermittent, but I grounded the plane until it was figured out.
First I checked the sliprings behind the gearbox on which the triple carbon brushes ride. They seemed fairly smudgy so I cleaned them gently with a Scotchbrite pad. Nope, that didn't make a difference.
Then I looked behind the panel on both sides to look for any loose wires and didn't find anything (I was also searching for loose grounds that might be related to the audio static).
Since nothing turned up it was time to take a look at the brush assembly since I've heard of others having issues with those.