Thursday, February 4, 2010

Paint & Final Weigh-In

I used Krylon H20 to prime and paint the wing. On the top surface I used the primer, then two coats of white. On the bottom, two coats of red only- no primer. The primer didn't appear to help with coverage or tack, 3M painter's tape still pulled the white paint off of the reinforcement tape even after a day's dry time.

The All-up weight, not including batteries, is 330 grams. Paint, glue, hinges, tape and spruce spars added approximately 111 grams. If battery weight is included, with the 1050mAh 3s flying weight should be around 430 grams.

Then, plugging the numbers back in to webOcalc:
Flies Like: Backyard Flyer.

Power Level:
(with white highlighted prop) Amazing. Extremely 3D capable. (9x6 prop)
Thrust/weight about 2.2:1
Minimum Pilot Skill Needed: Beginner level.
Minimum Flying Field Size: 1000 x 730 feet.
Minimum Battery Capacity: 910 mAh, 20 C, lithium polymer.
Suggested ESC Rating: 20 A to 24 A.
Power Into / Out of Motor: 194.4 watts in / 145.8 watts out.
Power To Weight Ratio: 205.99 watts/pound.
Estimated Stall Speed: 12.4 mph.
Wing Loading: 6.43 oz/square foot.
Cubic Wing Loading: 3.96 oz/cubic foot.
Maximum Pitch speed: 50.9 mph


  1. So the theoretical max speed is 50.9 mph? I thought your other planes already do that? Or is this the test and the next one is going to be the all-out speed demon? Just curious.... Don't get me wrong, I'm still impressed that you're making your own plane, but I thought we were talking over 100 mph.

  2. When do you think you will get out a fly it? Get some video.

  3. You are right, this is only a prototype. My current P51 is much faster than this wing. I want to see how well this wing design and airfoil handles- if it works well, and is easy to control I will be transistioning to PHASE2 of the top speed program. A big part of the flying performance will be launch technique...

    I think John's proposed technique is going to chop his fingers off.

    I'm planning on test flight number one this weekend. I'll definitely get video!