hi friends i have made a 8inch wingspan biofoam(4mm)catapult launch glider.
materials:
1.biofoam of 4mm thick
2.bamboo for fuselage
3.balsawood for fin
problem:
1.foam of wing bends when launched with full stretch by catapult
solution:
1.given a reinforcement in the wing with 0.2cm thick woodstick used for home-cleaning.

question:
1.shall i need to give reinforcement for tailplane?
2.what are the materials can be used for reinforcement?
3.how should i groove in wing for placing the stick for reinforcement accurately?
thanks
karthik

The groove can be made in more than one way.

1. Take a piece of stick of the same dimensions as the spar and stick fine sand paper along the width. Use this to "sand" the groove. Keeping a scale along the line where the spar sand the groove to the required depth. This approach will take some time though.

2. Use a new knife and make a groove. Then use approach (1) and sand the groove to shape.

3. Use a mildly hot soldering iron and then use approach (1) to sand the groove to shape.

I've done approach 1 on a foam glider a long time back and it came out very well. Search the net and you will see many approaches.

normal clear tape is good for wing reinforcement.just use 1/2 inch wide tape near 25-30% of wing chord top/bottom and make the wing placement thing using normal foam should give you good support n still be light weight .

remember one wants to keep his glider as light as possible !

sahil

Your glider is too small

It is apparent you are a beginner - try making one
of at least 12" span - also biofoam is not
the ideal material for a cat glider wing.

If you have to make it out of Biofoam then
make a wing with some sweepback - like a fighter plane
the planform of a hawker hunter wing would be ideal.

this will help it handle the high launch speeds.

all the earlier posts re: reinforcement should be considered.

I got into RC/aeromodelling too late, and my current schedule does not allow me to experiment with such gliders     

It would be great if you can post some videos.

PS:  I have lots of time to fight in favor of Futaba

since its a very small glider..use a hollow carbon tube for reinforcement..even a 1mm thick solid carbon tube would do...rc dhamaka has sum carbon with them..and sincd ur into scratch building now...i wud suggest order a few carbon rods(hollow and solid) ans stock it...always comes handy to aeromodellers..