Dynaflite BoT Airfoil?

[Seadog]

A friend of mine had a losing confrontation between his BoT and a HT power line this weekend. The result is a mashed up (2 or 3 bays) wing and a cracked fuselage. Fixable, but will need some replacement ribs. Can someone tell me what the airfoil is on the Dynaflite ARF?

Thanks

Dave Smith

[ejett]

Nope. It doesn't say in the kit info for either the ARF or the kit. They say and I heard that the ARF airfoil is not exactly like the kit airfoil and neither is like Dave's original.

The original wing airfoil (Dave Thornburg's original airfoil) should work fine on the ARF fuse, but you will need some plans to work from and make some modifications to bolt the wings to the fuse. Assuming you would want to go to the trouble of buildin a new wing.

I'd repair what you have. 2-3 wing bays does not sound too bad.

Depending on where the damage is (center or tip panel), you could trace the rib outline at the end of the center section and work from there. If just the part in front of the spar is damaged, just cut the sheeting next to a good rib and trace the shape on to your balsa rib stock. You will have to trim it back to allow for the sheeting, but it is easy to do.

I did just about the same thing with the club's windsock pole. I was able to piece together the damaged ribs to get enough to work with for the repair.

If the damage is in the tip section, then it gets trickier. You can use one of the shape duplicating gizmos to transfer the profile from the good tip, but you would have to fit the bottom and then the top.

I'm sure others will have as good or better ideas than mine.

EJ

[Bax]

You can get a good start by getting the spars set. With the spars set, you know the maximum thickness the wood has to be. You then make rectangular pieces that fit between the LE, spar, and TE. They will fit front to back and be as tall as the spar. You then use a straightedge and a sanding block to get the ribs even with the ribs inboard and outboard of the broken area. Works on tapered, elliptical, and constant-chord wings.

bax

[solo6796]

I am building the Dynaflyte kit, but I used the George Voss Lazer cut ribs. Got the originals....Pay the postage and tell me which ones ya need.....

AJ

[Seadog]

Thanks for the input guys. I am sure I can rebuild what we have left, as I personally strained an Oly II through some power lines many years ago, so am familiar with the feeling! I just thought that if it was a known airfoil I could print it off and get it right without fiddling. As the damage is on the constant-chord center section, I have no problem working from the root rib and reducing by the sheeting thickness.

Be flying again in no time, but like all of our sailplanes, it is now past the point of "the lightest it will ever be." They just get heavier from now on!

Dave

[BMatthews]

It didn't have a "proper" number or name. Dave Thornburg designed it himself using the normally accepted trends of the day. The reasons and shape details were detailed in the original article in RCM.

Either take up solo on his offer or perhaps someone could scan the plans for you.

[schrederman]

If you're talking about a Mark's Models kit or a Dynaflite kit, it's supposed to be an Eppler 205. However, a friend took my templates and made ribs, and compared them to a 205 and said they weren't the same. The original used a different airfoil that Dave cooked up. Those were only in his hand-cut kits. I'd be willing to bet the ARF matches the kit...

Jack Womack

[Seadog]

OK...tonight my friend is bringing it over and I will be performing exploratory surgery on the damaged Bird. I'll trace a rib, get it into Profili and try to get a match for future reference. Someone else may need to know, sometime!

Dave

[Les Horvath]

[QUOTE=Seadog]A friend of mine had a losing confrontation between his BoT and a HT power line this weekend. The result is a mashed up (2 or 3 bays) wing and a cracked fuselage. Fixable, but will need some replacement ribs. Can someone tell me what the airfoil is on the Dynaflite ARF?

Thanks

Dave Smith[/QUOTE
Hello Dave! The RTF BOT is 10% Clark-Y
Les
"Compufoamcore.com"