Foam board super light glider?

[flyboa]

Maiden this morning. 2 meter rudder/elevator only. AUW 166g.

 

[rfd]

nice. RE hi-start/winch gliders work best with polyhedral wings.

 

[flyboa]

nice. RE hi-start/winch gliders work best with polyhedral wings.

I tried to bungee launch today. First launch didn't climb and second launch had too much elevator and the wing folded. Definitely won't handle a hi-start.

 

[rfd]

i saw the posted image of your hi-start on rcgroups, and it looks kind of robust for a super light 2m. length of rubber and line is important for both the plane and the wind conditions. have you scaled the hi-start tension at various distances?

 

[flyboa]

I hope you build a light 2m glider soon. I would love to see it launch. My technique is off and no room for error on these foam wings.

 

[rfd]

I hope you build a light 2m glider soon. I would love to see it launch. My technique is off and no room for error on these foam wings.

2m RE out of DTFB? not gonna happen for me. not good for the nor'east winds, weather, and hi-starts. only interested in DTFB for 1m and 1.5m DLG.

i think the problem yer having with a 2m off a hi-start is that the launch is radically diff'rent from a DLG, where the HS "kites" the glider up, which puts enormous pressure on the wings that travels right down to the root. the wings and where they're attached to the boom would need to be greatly strengthened. i think it can be done, but with sparred wing halves that are joined together and glassed at the dihedral. the polyhedral joints won't need strength, it's all about the root. then the wing needs to be cradled to the boom, which means something like a wood pod or a wing saddle on the boom would probably be better. rubber band attachment would work well, and wings could be swapped in/out easily and bands will also minimize wing/boom damage on, er, um, "forced" landings.

 

[flyboa]

Not doing hi-start. More like zip start. Sometimes called bungee launch. Launch straight out similar to my DLG launch. I will post video if I get a good launch.

 

[rfd]

doesn't matter what you name it, they all do the same thing when you throw the plane forward. i've built at least a dozen hi-starts, with from 3/16" to 9/16" good latex rubber that runs 20 feet to 100 feet, and lines from 50 feet to 450 feet. it all depends on the plane and the weather. it still appears that your glider is not built strong enuf to handle a rubber start "kite".

 

[flyboa]

That may be but it won't hurt to try. My DLG were not supposed to fly either.