Well here I go. I'm ready to cut myself a wing with my new feather cut system for a home made dlg. I'll be honest - I have no idea why this or that airfoil works good. I have a general idea, but it's still kind of mysterious to me. So, before I make the templates and possibly waste time by making the wrong ones I thought I'd run my ideas across you guys hoping for a little direction.

I'm looking to make a 40" dlg at the moment. Soemthing I can fly anywhere (at my house, at the park, whatever)I do not want to bag or fiber glass it - I will get into that eventually, but for now I just want to make something rather quickly. I will be buffing the wing up with CF rods/strips and I also have some CF Tow I can glue on. I will then cover it with packing tape.

I realize I will not be getting super high performance, but that's ok with me for my first attempt.

So, with that in mind is there an airfoil or airfoil combo that would best suit me? I understand some planes have a different airfoil at the root than at the tip. I did a little looking around and am considering making either:

-AG04 (root) to AG08 (tip)

Or

-AG04 (root) to AG09 (tip)

Please correct me if I am wrong about using the AG04 for the root if it should be for the tip instead. I am basing the last combo off of the SuperGee which I found at http://www.charlesriverrc.org/articl...apogee40Mb.pdf .

Am I going down the right path here? Should I mabye try a different airfoil that I don't know about? Would I be better off starting with a single airfoil instead of mixxing them?

One last question. How do you go about deciding on a chord size for the root and tip?

Thanks a lot for any guidance.

-Mike

Helo Mike
I have no experience building the 40"hlg - I am on the homeward leg of building a supergee.

I suggest you stick to the excellent plan you already have and use your thinking time working on building techniques - this will make the biggest difference to the quality of your model then stressing over airfoil selection. On the Apogee page there are recommendations for a DLG cross tail.

An advantage of building as suggested is that you can follow other build logs and monitor the development of you building skills. Some very good threads in this forum on building Apogees (use the seach function - luke!) - very popular and flys well acording to reports.

Go cut some cores!

cheers Jeff

Aileron or R/E? I scaled down a Supergee for my aileron 40" and have been very happy. Span reduced to 66% and chord to 81% to come closer to the Apogee plans. I don't have an airfoil program that works on a Mac, so I have no idea what I did to the airfoils, but it flies great. If you are going R/E just use the templates on the Apogee plans from Charles River.
Jose at http://www.flyecm.com/ makes and sells the Apogee and is a good source for booms and parts.
I think you will be dissapointed with the packing tape covering. Maybe look into Polycrylic and glass if you're not willing to bag, I've not used it but I know there are some DLGs out there that use it.
The important thing is that you are doing it. Foam cutting is a skill that requires some practice. I got into 40" as a way to get the skills to make 1.5M stuff without wasting large amounts of material, but that's on hold right now because the 40" stuff is so much fun.

I believe when I did what you are talking about I used the AG03 at the root and the AG04 at the tip. I'd have to look at my templates to be sure. I used a 6" root chord and a 4" tip chord.

I say go for it. Learn to cut the cores first and then worry about glassing and bagging. Sure, it may be heavier, but these are your first wings and you will learn a lot. Glassing and bagging isn't hard, though.

I'd also be prepared to make a lot of throw away cores. Again, it isn't difficult, but there are some techniques that have to be learned. Once you get these sorted out, you are pretty much good to go. There is a lot of great information here and on the web about how to cut cores. Spend the time to do the research.

Good luck and let us know how it turns out.

Mark

Thanks a lot for the replies guys. Some info. that really helped me out. I'm excited to get going. I picked up a used Tekoa System from another member on the boards and it works great. I had never cut a foam core before and I for a test I cut out some cores for a 20" flying wing and my first attempt is a success. I don't see any flaws, but I'm sure there are a few minor ones.

Thanks a lot for the replies, I'll keep you all posted on how it goes.

-Mike