Elastic Launched Glider C

[asdf9799]

how do you know what length and width you should make the wings and the fuselage

[_HenryHscioly_]

maximum wingspan is given in the rules manual as 30cm
fuselage is not constrained, so different lengths should be tested
I would start with fuselage length the same as wingspan, then try out longer and shorter fuselages from there.
Testing and trimming gliders will be very important for the event

[wlsguy]

Just curious, does anyone know the winning time from Nationals last year when this was a trial event?
(Single flight or combined)

[chalker7]

There wasn't very good participation at nationals last year, I believe only ~15 teams showed up. I don't remember the exact winning time, but the combined times were something right around 20 seconds (2 10 second flights) in a ~25 foot ceiling.

[asdf9799]

how would you curve the wings on a glider?

[retired1]

the first thing to do would be to draw your proposed shape on grid paper and then fold it to see if the 2 wing halves are identical.
With another set of hands to help keeping it from moving around (no pins and no glue), trace the shape onto the balsa. I have a band saw and a scroll saw that I would make a cut near the mark. You could use a razor knife to cut it out, but that is prone to boo-boos on thicker balsa, not to mention slips that can cut you.
Then using a razor knife gradually trim the balsa back to the mark and finally use a sandpaper block to get the exact shape that you want.

[chalker7]

For ceilings under 30 feet, I wouldn't use anything thicker than 1/16", leaning more towards 1/32" and thinner (made by careful sanding), balsa for your wings. Anything more than that is too much structure and adds too much weight to the gliders (which is the number 1 enemy of flight times.)

If you are talking about curvature as in airfoil (the cross section,) there are two major ways of getting that to your wing. The first is to manually carve/sand it in using fine razor planes and sand paper. That's time consuming but necessary if you have a thick sheet of wood. The second option, if your wing is thin enough, is to curve your wing using a standoff or support structure below the wing that is then permanently glued on to give it a curve. This plan: http://www.indoorfreeflight.com/glider/cai1gli.gif demonstrates that technique in the side-view.

[BlueRed07]

Sorry if this question has already been asked, but when the rules say the nose of the fuselage must be less than ~ 13.7mm, does this mean the nose with or without any ballast(such as Plasticine) that changes the size of the nose?

[retired1]

I find the plan for the feather shooter a bit unusual. For the wing, it calls for 1/8" 5 # A grain balsa, yet the listed high point is 0.038 or just a bit over 1/32. Any idea why he is starting that thick and sanding so much off??? Also has a 0.020 x 0.020 basswood leading edge that appears to be sanded to near nothing.

[retired1]

Sorry if this question has already been asked, but when the rules say the nose of the fuselage must be less than ~ 13.7mm, does this mean the nose with or without any ballast(such as Plasticine) that changes the size of the nose?

It calls for the nose to be larger than, not smaller than. My take is that it would include the clay or other non metal weight.