Wednesday, January 12, 2011

Beware of Rotating Parts!

At a typical modroc launch, any monocopter pads get set up nearby other pads in order to share launch control wires. I already posted about the [extremely] close call I had on the Pitchwing-2 first flight. This time it was another new monocopter called the Wig-Wag.

Right after takeoff the Wig-Wag drifted downwind slightly and the wingtip collide with an 1/8" stainless steel launch rod. The rod was mounted in the same launch rack that the Campitch-2 didn't hit. The launch rod was ruint [Texan for ruined, but with more finality], totally FUBAR! The only part of the rod that was still straight was the 1" section clamped in the pad base. One might expect the rod to be bent away from the direction of impact, or bent sharply toward DOI at the point of impact. Nope, neither. After the sharp 20-25deg bend away from DOI at the base the remaining rod length was bent in a continuous arc like a bow. quite strange really. I'm an old hand at straightening bent metal but this was scrap!

I owed Art Applewhite a new launch rod. Luckily I had some spares at home.

The monocopter wing was fiberglassed balsa and suffered only a 1/2" deep notch in the leading edge, and the MC went on to complete a nominal flight. That's right, it kept on flying.

Repairs were relatively easy. I sawed out and replaced a square of balsa, filled the gaps with Cya and micro balloons, then sanded the fill to shape and reinforced the area with a fiberglass patch. Since the wing is already a veteran of many flights on the Pitch Wing 1, I didn't even bother to touchup the paint.

I'm glad this first flight was only on a C6, if it'd been a D12, damage might've been much worse.

Campitch 2, 1st Short Hop

Pics by John Lee

These are pics of the Campitch 2's 1st flight. Just a test hop if you will. I would've posted these pics before if I'd known they existed. They were uploaded out of flight sequence at Flickr, so I didn't find them till the other night.

When I designed the CP-2, I meant it to be an 'E' powered monocopter and I succeeded well. A 'D' motor barely gets it into the air as the photos illustrate. Only about five feet up, woo-hoo!

I hate "reinventing the wheel" [Unless it can become a perverted mockery of science!], and I see no point in rewriting the flight description when I can copy & paste from one of my own previous blogposts.

>>>>>The first flight back in August [2010] had us rolling on the ground, and we weren't even on fire! I launched the CP-2 on an Estes D12-3, it took off from a 2x4 pad low on the ground and ascended to no more than 3ft [more like 5ft] as it travelled 5-6ft upwind, then curved left going just over a modroc launch rack passing through a gap in the launch rods with scant centimeters to spare, then it drifted back downwind to land right next to it's takeoff point. It looked a lot like an olympic highjumper in action.<<<<<

Lucky thing, one of the launch rods was missing that day. [And that leads to another story.]


I haven't posted lately because I had to move. With major assistance from my brother, I started moving early Thanksgiving week. It took us nearly 2 weeks, after which there was a lot of settling in and rearrangement of storage, closely followed by more holidays.

While I have my own PC up and running, it currently has no online connection. I have to borrow time on other computers.