US Youth glider program like the Lithuanian one

[Hephaestus]

Stay way from eps in any load bearing application.. One of the easiest to make wings looks like lak-16 - sandwitch construction without ribs or normal spar. Just skin is enought on such a low speed wing.

That's the conventional wisdom yes. Monocoque works, but due to the risk of damage in ground handling / incidents - it becomes a poor (and more expensive) choice. The current wing design is an XPS skin that varies in thickness with XPS spar/ribs inside. But the construction man-hours are much higher than we'd like.

In my design there's no option to run it as a full monolithic block, but there are areas where it could still be used molded as a component of the overall design.

 

[stanislavz]

with XPS spar/ribs inside.

Can show it ? That lak 16 wing have 600gsm of fiber glass outside, 300or 600gsm inside. Build for handling.. And easy manufacturing. Some flows with choosen high loft airfoil.

 

[Hephaestus]

Can show it ? That lak 16 wing have 600gsm of fiber glass outside, 300or 600gsm inside. Build for handling.. And easy manufacturing. Some flows with choosen high loft airfoil.

Not yet... At some point yes, I've learned my lesson about being too open already.

I thought the lak16 was wood/fabric or fiberglass D-tube ribs and fabric?

 

[stanislavz]

I thought the lak16 was wood/fabric or fiberglass D-tube ribs and fabric?

All three

Reusing wood fabric wing from bro-11, full composite "baguette" wing, high lift airfoil, composite d nose + fabric rear with R3 airfoil.

Full composite was smallest one, full fabric - largest one. With R3 airfoil - the most loved one by students - best quilities for beginner glider.

Beiing framed glider with short span strutted wings - you may use half of your weight for wings. ..

 

[Victor Bravo]

If you do work off truck mounted winches (which I believe is a little more involved than parking a truck - sliding drag resistance isn't THAT much (think 1/3 truck weight) probably requires at least some wheel chock style ground anchors to 'bite' into the ground) you at least have the option of repositioning into an area where some weaker ridge lift or some stable thermals can be found nearby for more enhanced training activities.

The use of winches for "normal" soaring operation is a separate subject than for primary ab initio training in my opinion. There are already many different winch options like that, and the majority of soaring in Europe of course is done that way.

But for the purpose of this discussion on low altitude "ground skimming", at the minimal cost, then I think the weight of a 2000 pound pickup truck, and maybe a pair of wheel chocks, should be enough to restrain any reasonable loads that can be generated form a 500 pound glider at <40 MPH.

 

[Hephaestus]

The use of winches for "normal" soaring operation is a separate subject than for primary ab initio training in my opinion. There are already many different winch options like that, and the majority of soaring in Europe of course is done that way.

But for the purpose of this discussion on low altitude "ground skimming", at the minimal cost, then I think the weight of a 2000 pound pickup truck, and maybe a pair of wheel chocks, should be enough to restrain any reasonable loads that can be generated form a 500 pound glider at <40 MPH.

Ah I don't think ground skimming if it's got wings forward motion I want to go up

 

[Riggerrob]

Why am I picturing heavy-duty wheel chocks with spikes that penetrate the grass?

 

[stanislavz]

Made some calls - solutions with endless wire-loop was more stationary, than mobile and easy to move to new location. And that little gliders really do not need a big pull to get airbone, and even less for level flight.

And if you want this :
but for gliders, i bet you wont find better solution, than china made electric quad with remote..

Like this one : 4X4 Electric ATV, 4000W Electric ATV, 4 wheel drive electric Quad bike

Or this one + simple frame E Rickshaw Rear Axle. DIFFERENTIAL TYPE 1000W-5KW - 60Volt 5Kw Bldc Motor Manufacturer from Chennai

~ 1000 usd here.