Rubber band length?

[42-n-startinagain]

Where do the rubber band guidelines come from? Saw some recent videos and it looks like the bands are really long, 3 times the fuselage length or so. It further looks like the bands are wound up with almost no tension. Props must kinds of waft in a circle and the planes more glide and float.

Seems one could overbuild and use Uber high rubber tension and get short but fast and furious flights. Like a proper war bird.

No?

[kittyfritters]

The starting point that I use for loop length is 1-1/2 times the hook to peg length. A good starting point for the motor size is 15 percent of the empty weight of the model in F.A.I., tan, sport rubber. I weight out the first motor and make up my loops. For that model I would start with a motor of 3/16" flat rubber. If flight testing indicates the need for more torque you could go to 1/4" inch rubber. If the torque is excessive go to 1/8" rubber. When you get the right power level you can just make the motor longer for more duration, but watch your balance. It's a good idea to get the Don Ross book, Rubber Powered Flying Models. The winding chart on page 91 will give you the safe limits for winding motors.

Hope this helps.

[42-n-startinagain]

Yep makes sense.

[scigs30]

If I have a competitive sport flyer, I will use more than 1 1/2 rubber. For most Guillows builds I stay at 1 1/4. I never count my turns, I just go by feel. For size of rubber I keep it real simple to start with and then go from there.......14-20 grams 1/8 rubber, 20 to 30 3/16 rubber. Over 30-44g I will normally use 2 loops of 1/8th. Now remember those are just starting points. This is the basic stuff I learned back in the early 80s and still works today. Another great book that I highly recommend and will improve your trimming abilities is "Peanut Power"
http://www.amazon.com/Peanut-Power-Worl ... 29-9661151