I was thinking more about the wing shape than its section....

A combat flying buddy commented that "the only way to have more fun than this, would be to add fire to the equasion".

So here's what he did to an indoor Drenalyn I build for him. I guess it's going to be indoor combat next week.

Frank That looks a treat.. The wing plan shape seems to be more like a PBF with round front corners than the classic Drenayln shape....

Yup, round at the front and the ends parallel to the centre line for a bit more wing area.

There are now five Drenalyns (so far) ready here for indoor which starts next week. I'll get a group photo to post. I think the guys were getting a little bored with the Smart Dart and the Drenalyn is capable of doing much more, which means more fun.

Frank it's on my list...... I have you thought about a Drenaylnised NB?

Couple of video frame grabs of David Theunissen's Drenalyn almost 7 years ago - November 2001 (pre brushless and LiPos)!





David's site: http://www.flyelectric.ukgateway.net...r.htm#drenalyn

This was the first indoor model I ever saw hover

Originally Posted by goldguy

Getting ready for the indoor season. Here's my latest, a 16 incher with a 16g, EPP and complete with a 'bent in' airfoil. With a loading of 2.5 onces per sq. ft., you know it's a beauty, a real performer for small, or big, spaces.

Is this EPP version built to the plans that are linked in this thread? I'm sure you can resize to any span you like, but is the bent-in airfoil always the same, as well as overall proportions?
MKH

Just my version and the airfoil is TLAR. Size to to suit your equiptment weight to keep the loading down.

Frank, got a question. Have you tried an undercambered SD with a rudder? Or, would it be of benefit in a delta as opposed to a low aspect form like the drenalyn? Also, does the bent airfoil have better low flight properties than a clark y. It seems that a flat fuse could have a couple of ribs over the flat wing wing taped or glued that would have the strength of a kf with a "real" air foil. Or would any benefit be lost due to the added weight if any at all? I have been thinking again this evening which as always can be dangerous.

I posted a pic in the SD thread of the 'Don't Panic' delta, which has an undercambered wing. The designer claims it eliminates the pitch or tunking problem, which all my SD never had, so why bother with all the extra work.

Now the Drenalyn, that's a different story. The undercambered and reflexed wing with the round LE is it's secret to success, as least that's my impression. The shape of the LE provides dihedral effect, the shape of the wing produces extra lift for slow flight, the reflex keeps it on an even keel and the bend provides strength for the foam saving the weight of bracing, even floppy EPP. Even with the UC airfoil, it flies inverted as well as upright.

A clark Y wouldn't work well on a platform that has no tail as it needs reflex. Designing the reflex into the airfoil is more efficient than adding up to the elevons as that only produces more drag.

Had three Drenalyn show up at indoor last night and they are by far the best all round performer I've yet to find that uses elevons and/or rudder, kind of like a improved version of the Pizza Box Flyer.

The SD is pretty viceless.... you don't need a fancy airfoil. A simple KF section won't hurt though....

Would it be rude to ask for some nice tiled pdf plans in english? Can't make things too easy for us noobs you know, but this plane looks intriguing...I have an eflite park 250 and 6gm esc it might go good with?

Removed

There's a problem with building from that plan. If you look at the side view or the airfoil, the LE goes down too far and the reflex is excessive. There was one built here from that plan and it needed modification to get it to fly properly. If you draw a straight line and draw the airfoil so no portion of it goes below that line, problem solved. Any fuse or spine that's added, is below that line. Just look at the picture of mine. Also note, that the LE only has to come up in a sweeping fashion (the reflex) about 1/4 to 3/8" on a airfoil with a 18 cord.

The shape of the airfoil doesn't seem to be critical and a free hand TLAR is good enough.

The link I posted above (#51) is in English, and has pdf and cad plans.