Hi! I built a QF2 recently... Only to find out that my wounded knee doesn't like DLG launches!
I'd like to fit a tow hook to the QF2 so I could up-start it. How do I figure out where to install it? And I'd like to find a source where to buy an adjustable and light hook, if you know any.

Thanks again!

That's too bad! Have you tried side-arm launches with it? You won't get nearly as high, but you should still make a decent height. It's a lot easier on your knees, too.

For tow hook location, it goes just ahead of the CG. I would start with maybe 3/16" or 1/4" ahead, and adjust from there. Moving the tow hook back will improve your launch height, but if you go too far back, it will start to get unstable.

If you want to experiment before committing to a tow hook, give this a try: http://www.charlesriverrc.org/articl...20Gallagher%29

If I was going to put a tow hook on the QF2, here's how I'd do it. First, glue some 1/16 ply into the bottom of the fuselage, extending maybe 5/8" either direction from where the tow hook position will start out. Make sure it ties in to the triangular stock in the corners of fuse. Then cut a slot through the bottom of the fuselage and the ply, stopping 1/4" short of where the ply ends. For a hook, just use a small, partially-threaded bolt, with the unthreaded portion bent into a tow hook. Cut the screw head off and smooth it out. A #4 size screw should be plenty big; smaller would be fine if you can find it. Put on a nut, then a large-diamter washer, stick it through the fuse, then do the same on the back. Tighten it down in the position you want, and you're good to go.

The Allegro uses a pretty similar tow hook design, see the plans for an illustration: http://www.charlesriverrc.org/articl...te2m/fuse1.pdf

I think that might be overkill for such a light glider. For an appropriately sized high start, a paper clip would probably be strong enough! Not for a larger high start, of course.

You might consider more of a catapult style with the hook further forward so you can zoom launch off of a wider but shorter piece of high start tubing.

For a hook, I'd just pick a fairly small cup hook (see URL below), maybe #4 thread size (is .112" dia or around 3mm). I'd cut it off maybe a quarter of an inch past that first bend and bend it with pliers until it looked like an "L". Put a small piece of plywood where you're going to screw it in. You can make holes every eighth of an inch or so for adjustment.
http://images.lowes.com/product/conv...36697568xl.jpg

Why not tow the DLG glider, any small foam plane can tow it.
Just use a piece of velcro as tow coupling (1/2 to 1 " long)
To release just pull hard up, or the towplane make a half roll and go vertical down.
Last weekend I towed many gliders in that way inc, DLG gliders.

This way:

Cool young RC glider pilot. (2 min 21 sec)

Towing the Limit Ex (0 min 55 sec)

Towing with flying start. (1 min 32 sec)

Good luck
S

I have seen an Easy Glider towed with a tri motored Lazy Bee. Fairly amusing. But more trouble than a high start, of course.