Mini Katana Repaired

Okay, I didn't build this one. I bought it almost ready to fly from Atlanta Hobby It flies great. It has a 250 Watt power system that puts out 1.5 times more thrust than the airplane weight. The great thing about the Mini Katana is that it flies like a normal airplane. Most 3D capable airplanes are strange in normal flight, but this one is a joy. It does beautiful touch and goes, knife edge, tail slides, etc, but it will hover too. The dry airframe is only about 13 oz.



Why the odd white triangles on the wings? Well, my dumb-thumbs flew her a little too low... I scraped the landing gear off, broke the motor mount, and destroyed the lovely fiberglass cowl. Now she is all better. The worst damage was from the sharp back-ends of the wheel pants poking holes through the wings. I had to do fairly major rib and sheeting reconstruction. Unfortunately, I don't have any transparent red covering, so I patched it with white.

RC Trainer "Cutie"

My youngest daughter and I built this trainer together:


This kit is fully laser cut, and it was a joy to build. It even has laser cut lexan parts, including a little hook that holds the battery hatch down. I got the kit from SR Batteries



Mary picked the nice color scheme. The airplane was designed for a speed 400 brushed motor and gear box. The brushless installation is just so much cleaner. When I was in high school, I built a Lee Renaud designed Q-Tee. It has an internal-combustion .049 engine, and flew great. This one has so much more power, but weighs about the same.



The first flight was in a fair amount of wind, but this plane is not as light as most modern electrics, and frankly, for training in a bit of wind, it is perfect. It flew very nicely. My daughter handles it pretty well. Landings are easy.

Every year, my flying club, the the Torrey Pines Gulls, does a flight demo for Torrey Pines Elementary's Science Discovery Day. We demo to three groups of about 7 kids for 25 minutes each group. The last 10 minutes we line them all up and let them fly a few circles around the sky, under very close supervision. I usually loose a plane this way each year, so I bring cheap foam trainers. This year we had a lot of wind and the foamies were grounded. I decided to let them fly my daughter's plane (I know, stupid). Well, it went perfectly. It was easier for the kids to fly, and it has so much power, I could climb to altitude after each kid's turn really quickly. So, now I know the secret: you have more to loose with a good trainer, but much less chance of actually loosing it. Anyway, the Cutie has only four flights so far, but about 20 pilots!

Brass Strut for 1907 Firestone-Columbus

My father has a very rare 1907 Firestone-Columbus horseless carriage.



He needed to fabricate two roughly 3" tall brass struts to prevent the rear bar that supports the motor mount from bending. We drew a sketch of the part, then I drew it up in TurboCAD Mac.




I 3D printed two copies as patterns for sand casting. He had them cast in red-brass. He still has to machine the top to act as a cradle for the truss rod. I was going to put that feature into the pattern, but my dad pointed out that the patterns wouldn't come out of the sand cleanly if we did. The casting is rougher than the pattern, but preserved some of the fine patterns left from the FDM extrusion, which actually looks kind of cool.


The brass casting is on the left, the ABS pastic pattern is on the right