Haven't seen any FF DLG/TLGs on the forum (except my own!)

But if you are flying an FF DLG, you might be interested in the kind of loads on the model at launch.

As a high handicap, senior citizen, i guess my golf swing speed is as low as 60mph.
(Tiger Woods over 120mph)
Compared to a golf club, i assume my TLG radius is about 2/3rds, and the speed is therefore about 2/3, or say 40 mph. Perhaps a bit more as the model is far lighter than a golf club.
Say 45mph (or 66 fps) at 4ft radius.

So what is the side load on the model?
Compared to its weight.
Or mv(sq)/r compared to mg
Or v(sq)/r compared to g
Now v=66fps
So v(sq)=4356ftsq/secsq
If r(radius) is 4ft
So v(sq)/r= 4356/4 ft/secsq, or 1089 ft/secsq
As G is 32ft/secsq
Dividing, we get 34G!

So my 50gm model gets a side load of nearly 1.7kg!

That's why the wing to fuselage joint breaks!

If there is any interest, i'll discuss tail boom flex next.
You'll be shocked at how much the tail boom flexes!

Hope there are some readers for this kind of stuff...

I dont know anything about it sir, but I read it, and now I ll go and google what DLG  is.

Great info sir very much interested in this.
Wow thats quite a bit of stress. Sir but if there is no flex would it have any advantage? A DLG reaches high acceleration in a very short period if there is no flex will it hold up?

Also never understood how a well made dlg doesnt spin at launch, right wing half should be creating less lift than left wing half right?(Assuming right hand launch) The turn radius closer to the center of axis(the person) is small so the wing side closer to the axis should have a greater lift right? So at launch dlg should spin outwards

@miginstruments
These are just variants of hand launch or 'chuck' gliders.
DLG/TLG is Discus Launch / Tip Launch glider.
Instead of holding the fuselage under the wing and throwing like a javelin, these are held by the wingtip and thrown like a discus.

@RcNeil21,
During discus/tip launch, the outer wing covers a greater distance. Hence going faster and producing greater lift than the inner wing. After a right handed launch, it rolls left.

You may like to see the sequence of 12 photos during launch/climb in reply #77,78,79 in :
www.rcindia.org/kites-trains-free-flight-and-all-others/for-the-5th-sweepstakes-first-model-k-k-iyer/msg181492/#msg181492

Oh very nice sir n thanks for the info. which material ll be suitable for building this glider. I ve Corro material can I use it.

@miginstruments,
I've been using balsa for wing/tail, balsa+ply or balsa+glass cloth for fuselage front and 3mm CF tube for tail boom.
VC sir and Saikat sir may be using harder wood than balsa for entire fuselage.

No harm trying with coro, even though it may not be a good choice.
We will know when Rai saheb (sanjayrai55) makes one!

Hello Sir, the problem is I am not staying at Bangalore anymore, so getting balsa will be a bit difficult. Also I dont have CF tubes, although I ve got Aluminium Tubes. So I can try my hands on it with the material available with me. I had bought corro to build a plane, but my first attempt failed, again due to lack of materials. But I ve not given up, only thing is I am a bit busy nowadays. But I think a DLG ll not consume much time. Hope So. Thanks for your reply.