Hi,
Just completed the build of the Micro - B which is in the EZB class of indoor free flight rubber models.
Wing span 17 inches.
The target weight for this design is 0.75 gms or less -- has been built upto 0.45 gms.
This can be achieved if you have special indoor low density balsa ground to required thickness which is not available in India. Can be imported from guys specialising in this -- pretty expensive.
I managed to keep the weight down to 3.0 gms.
This model can do flights up to 20 mins if trimmed well and the proper propeller (pitch) and rubber thickness ( gives correct torque) combination is used.
Flights in the house show a stable glide and very slow sink rate. Seems promising. Proper test flights in large indoor space will be done shortly.
Pics of model and build details being attached.
Anant