Experiment autogyro build log
 

Ok, guys, this is the story. I've had a couple of gyros, both DC head. Then I tried to convert a plane fuselage into another gyro, with the expected disastrous outcome. Well, a couple of weeks ago I made a mockup gyro out of foamboard and although it flew ok, the structure was weak in torsion and it ended up breaking apart. So I decided to draw and build my own. Ive spent this week drawing, framing up the fuse, and building the column. Next will be to make the tail and gear, and finally the blades. The head will be the same from the mockup, which I made from a homemade plate of carbon and fiberglass. A word on weather, here in Abu Dhabi I went to fly the foamboard version at noon one day, and the black head got so hot that it got weak and the blades started drooping ever closer to the fuselage. Scary stuff, hehe. Well, I hope you like, and off course, I hope it flies

Fuselage is atandard truss construction, column has an inner birch ply base, then balsa structure and planking.

This is the head. It's Carbon and fiberglass sandwich, as I said, with regular 30min epoxy. I'll strengthen it a bit with ply, only leaving a gap to flex, as right now it's too bendy, specially when hot. Also, I'll try some 5 degrees to the flex, so the advancing blade will get a bit of down incidence. I', not using bearings, it's just a 3/16 music wire inside a brass tube, with washers and graphite as a lubricant. Yes, plain old pencil dust, it's the best dry lube, and dust and sand cant't get stuck

This attachment system I think is brilliant, and I borrowed it from Jim Baxter's Twirl design. Basically the column goes in rails and is then screwed from the bottom. It looks great inside and out.

Well, this is my progress. It's looking sadly similar to everything else, but apparently there's a reason for that. We'll see. No interest out there for the project, but I'll continue to post anyway

This is the reinforcement I made on the head, some screws are missing.

I'm a bit worried about the weight of the model, as the loading is going up to almost 4oz per sq ft. Thoughts?

Looks like it will fly to me..Better fly at night or early in morning so it will not melt.

Jim

This is the milling setup that I am using for the blades. At least they all end up fairly similar in shape. And check out my drink, hehe

Well, guys, an update. The project was a huge failure. After several attempts and flip overs I decided to just hand launch it, it just stalled upwards and fell to the left. At it was made out of sticks, that's pretty much all that was left. So it's back to the board

Ok, guys, the design was a huge failure; the gyro didn't even leave the ground, it would immediately flip to the right, I'm guessing too much "up" on the disc, and the disc was way too big for the bird, specially the stabilizer. So, deciding to start over, the only things I am keeping are the mast and the blades. My dad has a laser CNC in his factory, and a lathe at home, so in my last visit we got to work. I made some plans, we cut the parts an I just finished assembly and paint. I'm very happy with the result, the blades now flap mechanically and are hinged properly. The hub is aluminum, turned at home, and inside it has two 4x12mm ball bearings. I can't seem to find the thrust bearing I need for the top, but a couple of nylon washers will do for now. Check out the process and the result.


Mariano