I need some suggestions......

[lensrc]

I'm wanting to scratch up a balsa bird somewhat like the sig rascal.What I need to know is some numbers to shoot for.I want to use the motor from my soarstar,so I guess that would be in the speed400 size group.mostly just wing area and a good wing loading number,I can figure all the rest.Also I will be using 8 cell aa Nimh packs(Radio Shack).Thanks for any info you can give.

[lensrc]

JPEG of Plan

[Ollie]

A wing span of 36 to 40 inches and a gross weight of less than 28 ounces should give a lively climb with the right prop. The lower the gross weight the better. Try for a wing loading of less than 18 ounces per square foot. The lower the wing loading the better. The challenge is to build light and pick the right gear ratio and prop size. Moto Calc or a similar program can calculate the performance before you build.

[ChrisP]

I think you should be shooting for something like my Doddle - see : http://www.rcgroups.com/forums/showthread.php?s=&threadid=27481&perpage=15&highlight=pictures&pagenumber=24
If you want to go with a straight drive 400, you should limit the weight to 18 ozs. If you go geared, then up to 21 ozs. Geared (1.85:1) is a great way to go as you are then looking at 12 - 13 minute flights on 7x500 mAh cells.
These kind of models fly best at a wing loading of 9 - 9.5 ozs per sq ft. So a net wing area of 260 - 300 sq ins would be fine.

Your design looks a bit thin in front of the tailplane - breakage guaranteed, so you should deepen up the fuselage a bit.

[tim hooper]

My turn!

I'd go for a flat or undercambered wing section, with a couple of degrees incidence. We're not after inverted capability I assume?

I'd also guess that the aspect ratio of both your wing and tail is a little high.

tim

[lensrc]

The high aspect ratio is intentional.I like the "Old Timer" look of it,and like the idea of glider like performance.I can fine tune the stab area after I find my final wing area.

[lensrc]

How would one figure the area for this wing?I may just calculate the best I can,then rely on the LAR method from there.It's worked pretty well for me in the past....:D

[lensrc]

more work on the plan

[lensrc]

Man,I resized that thing to 5" across,what gives????