วันเสาร์ที่ 21 มิถุนายน พ.ศ. 2551

F16


Plans for depron F16 pusher prop

First I want to thank ezonemag.com for their great website, this goldmine of knowledge.

These plans are based on my previous F16. The plans are drawn by hand on A4 paper and then scanned to a PDF file. There is a construction drawing that shows all the pieces in place and a parts template drawing. All the drawings are tiled so it takes some time to put everything together.There is a number/letter on each tile. Start in the LH top corner with 1A. Go 1B, 1C, 1D etc for horizontal tiles. Go 2A, 3A, 4A etc. for vertical tiles All parts are numbered using the stepnr. they are used in. For example pieces 1A and 1B and 1C are the three pieces you need in step 1.
The new F16 is a little bit different from the old one for the following reasons:

-The size is about 10 % smaller. The AUW of the old one was 530 grammes which was just a little bit to much for my power system. It flew fine but I didn’t have a big reserve.
-This one only has tailerons instead of ailerons and a full flying elevator for much easier building

The aircraft is made from 6 and 3 mm depron. All bonds are made with styrofoam safe CA and accelerator. When I had to carve and sand after laminating several pieces of depron (nosecone) I did not use accelerator because it makes the CA too hard to sand. Spars and firewall are glued with 5 min epoxy.
In some areas it takes some sanding and carving, but other than that it is a conventional contsruction. The canopy is made with the thermoplastic bottleshrinking method. The wings have a 5mm diameter CF spar and balsa leading edges. The nosetip is full balsa and the belly is covered with a glass/resin strip to protect it during landing (this under –belly big intake damages easily).

My power system consists of the following:

PJ550 Brushless motor (60 grammes)
Kokam 1200 3S1P battery (75 grammes)
Jeti 8 amp BEC controller (9 grammes)
Multplex 4 channel mini receiver (10 grammes)
Two mini servo’s (8 grammes each)

I measured 450 grammes static thrust with 8 amps, and 6700 RPM and a 9X4,7 prop. Handlaunches were not a problem but I didn’t get very high speeds with this propellor. I guess I need a different set-up for that.