( Successful reflight at 7:00 )
NOTE my first attempt to upload my original video here with an AC/DC soundtrack was blocked by Youtube, so I put it on VIMEO instead and edited a new soundtrack for the Ytube version. If you would like to see that AC/DC soundtrack version instead then here is the link: https://vimeo.com/755849499
UPDATE: I found out the mushy controls were due to using a transmitter model memory stored for my C186/MCPX BL project, which has the servo travel reduced to 60%. Mystery solved. Not the heli's fault.
I recently acquired a somewhat damaged Blade MCPX BL2 fitted with a "Dragonfly" shell that makes it look somewhat like a vintage Hughes Schweizer S300 helicopter.
The ad said the main mast on this PARTS or FIXERUPPER heli needed replacing and that either the tail motor or the main board was dead. The $60 price was cheap for a used heli that sells for $200 new, so I snagged it. Well, it turned out that the bird had a lot more wrong with it, so I rolled up my sleeves, popped the hood and gave 'er a lookover. Fortunately I do have a good supply of BL1 parts that are compatible.
Tests showed me that the tail motor was OK, so looks like a control board issue... bummer. Fortunately I found a used board online for a good deal. I also replaced the bent aluminum mast . A titanium one that is available is stronger but would cost me about 50% more . Aluminum it is, and being a skilled Tool & Die machinist I was able to straighten the original bent one to use as a spare too.The frame had it's body mount posts broken off and the guideway for the swash plate had a section broken and reglued, so a new frame was ordered.
I decided to order some new BL2 main blades too, since the old ones were so battered. The Dragonfly fiberglass body shell goes for $30 shipped on eBay, so that was a nice extra. It has a few cracks in the gelcoat finish which is common with flexible single ply fiberglass, but they are hard to see.
The tail boom had broken and split near the frame and had been glued back together. The motor wires were wedged in and glued into the split joints in the shaft. A multimeter test showed that two of the 3 wires were shorted together, the insulated wire coating having been worn or forced off.
That's what killed the main board. I removed the old boom, split it apart to remove the wires, separated and sprayed them with flexible clear urethane paint to reinsulate them, then made a new boom from solid 3mm carbon fiber rod and secured the wires to it with heat shrink tubing. The new boom is 1/4" longer than stock for a little more tail authority and stability during high speed runs.
First flight test with the new parts did NOT go well. The shell rattled on the posts and the blades tracked very poorly. Also there was a vibration I could not get rid of. After the shaking knocked the main motor plug out and then the entire tail boom, I took it inside for full teardown and inspection.
.When I took apart the head I found the feathering shaft was bent 10° to 15° in the middle. That would explain the vibrations and poor blade tip tracking. I put a new feathering shaft and blade grips on from my supply of BL1 parts and they fit just fine.Next I fitted the fiberglass body shell with grommets to stop the rattle noise and drilled/inserted a tiny screw in the frame to secure the boom to it. I had to resolder one tail motor wire near the frame too. The new BL2 main blades arrive, so on they went.
For cosmetic reasons I stripped the decals off of a stock BL1 tail fin to make it solid white to match the 300S body. A BL1 tail rotor went on the back end and works fine until some new and larger diameter BL2 rotors get here.
The second flight test went much better, as seen in the video. Everything felt solid and stable, and I cannot think of anything else it needs. I like it now. A new and unique bird has taken roost in the DOGGehouse!
Note that my first attempt at a video was blocked due to the AC/DC music I used in the background.
Happy flying.