combatpigg

My Feedback: (3)

Hi Mr Clean! If you run into OzMo, say Hi for me, but give him a wedgie, too. He seems to be having more than his fair share of fun
Is your BullDawg a flat sheet wing? I'm trying to make sense of the original poster's troubles and also looking back on "the way it is" with PBFs.
Like I've said before, I've got some 1/2A flat wingers that don't oscillate near zero AoA, but have built larger and heavier versions that do. After running the CGs back and forth, I can't call it pitch sensitivity, it's more like when loaded down past a certain point, flat airfoils have a basic flaw that makes them unable to cope with speed. Keep them light enough and all is OK.

mclina

I am pretty sure that my problems were with the CG and with my short attention span. After this thing failed to fly on the second attempt, I think I just decided I had other uses for the engine and radio gear.

You should see the pile of SPADs in the corner of my basement....

Someday, maybe later this winter, I really want to build a delta that will fly.

Clean

Yes the Bulldawg from the SpadDawg's website is two sheets of 4 mil with a box on it. I flipped it over and made what I call a TopDawg for easier launches though I had problems with my cleaned up one, my first one was my bulldawg flipped around. My control surfaces were locking up because my servos attached at the very center and the wing bows pretty good. Servos in the center of the aileron gives no problems. But it's pretty stable surprisingly enough, course it's not light either.

http://spadworld.net/gallery/display...10161&pos=-461

combatpigg

My Feedback: (3)

Thanks for the link to SpadDawg. I couldn't make out enough detail to see what is going on, though. By saying 2 sheets of 4 mil, do you mean they are laying in a sandwich up to the hinge line of the elevons? Criss-crossed? It looks like an ingenius set up, especially for those days around here when the ground is soggy.
Getting a stash of 2 mil is on the "to do" list this year to try a project like this with.

Clean

You might be able to make a 2 mil 15 size version of the dawg, but the full size are 4 mil. In the uk they have a CoroRoo and it is essentially the same thing however it is a center 4 or 6 mil sheet with a carbon rod for a spar, then with a top and bottom 2 mil sheet, so it's actually 2 mil thicker all together but it gets down the road just as quick.

That is the nice thing about SPADs, clean em, don't clean em, don't worry about water damage, it's all fuel proof already. Only have to worry about tank leaks getting the gear wet.

They bounce pretty good too.

emeraude

what should be the dimensions for the 15 size ?

Regards

Clean

Don't know, I wouldn't cut it in half though, It'd have a bigger wing than the full size, you won't have as much horsepower to propel through the air at a high enough rate for lift. Maybe, 3/4 size? 2 sheets just like the original and a folded 2 mil fuse.

Clean

Even sent an email to his club. Still no joy.

Clean

Come on Avvro, you're killin me here.