Friday, October 12, 2007

SR - 71 BLACKBIRD



Here is an on-going project. This is a scratch built replica of my own design. As you can see there is still a lot to finish but I wanted to post a few pics just to show all the viewers out there what I can do.





The upper deck is "planked" with thin strips of balsa like you would build a canoe. Afterwards the area is lightly sanded to achieve an smooth contoured surface. Any gaps or imperfections are filled with spackle (or any lite weight filler compound) and sanded again. The result is a smooth seamless surface. This technique can be used to create complex shapes. With the rather small delta wing shape this plane will have to travel very fast in order to generate any kind of lift. A brushless/lipo motor combination will do the job I think......



Length : 38 - 40 inches
Span : 14 - 16 inches
Power : Speed 400 / Brushless / Lipo combo



This plane looks rather cool left unfinished....as you can see all the sub structure. This is why I have not finished it yet. I will one day.

2 comments:

Darrell Markewitz said...

Interested to know if you have calculated wing surface / lift against thrust from various power plants you have available. - and how these numbers may compare against the actual aircraft.
The SR-71 has always been one of my favorites, in terms of raw design and just what it * is *.
It still is a very weird airplane, leaks like a sieve at ground level, etc, etc.
You might consider commenting how the dynamics of SCALE effect translating real world full sized aircraft designs into working (flyable) models. Although I do not fly RF myself, I understand enough of the framework of the problems at least enough to appreciate what a task creating a good flying model can be!

witzworks said...

....thanks for the interest. At the time of original construction this plane was to be powered by a SPEED 400 brushed motor. Since then an entire generation of BRUSHELESS motors and LITHIUM style batteris have come on the market. I will no doubt power this craft with such products. It is a PUSHER style design (prop/motor located at the rear) so I will need a lot of power. Flight time will be very limited to the size and weight of the lithium battery. Even if I only get a 1 min flight I will be very happy.