Fred, I used Great Planes Pro-Formance foam 3mm. Not Cellfoam 88 which I like better but is heavier. I usually don't like the pro-formance foam cause it's really soft and will only sand well with finer grit foam sanding blocks. But the weight savings is significant! I was surprised at having a finished airframe, rx and fan minus battery at 21.1 grams. I am pretty proficient at Sketchup but haven't been able to print without distortions (cause I don't know what I'm doing
) so much for proficiency. This thing glides forever and I have crashed into the sides of the gym floor quite a bit but since the weight is so low the damage was minimal. I am drawing up plans tonight to scan and attach. If all goes well I will get a video soon.
Oh yeah, it's the 6 blade rotor.