hi guys , so i have never done delta wing aircraft before. I have a 2400 KV motor, i am planning to make a delta wing aircraft which weight less than 100 grams. how big the wingspan should be? and how should i design the aircraft? thanks

less than 100grams?!

like 10inches wide

Depends. What capacity/cell count battery are you using? That will be the main driver of how heavy the plane needs to be.
Once you find out how heavy it will probably be, you need to decide what you want the wing loading to be. Look around RCG, there are plenty of discussions about this.
Once you have the wing loading and the weight, you can calculate your desired wing area. Then you determine the dimensions of the plane from basic geometry (the delta wing is just triangles and/or trapezoids).
You should then choose an airfoil, I'd recommend the KFm2 or KFm4; it's hard to go wrong with them.
Last, use a CG calculator and then figure out how to arrange all your electronics and spars etc. to make the wing balance properly.
(this is really how to design any model plane BTW)

Then flyyyyyyyyyyyy. And post results.



OH! Just noticed! Welcome to RCG, where LEDs glow and props thunder.