best source for motor rubber?

[twospruces]

Hi everyone; happy holidays!

I'm wondering what is the best place to get really good rubber for free flight rubber power?

thanks!
Steve

[atesus]

This place would be my first choice.

http://www.faimodelsupply.com/

A2Z corp also sells the SS rubber.

http://www.a2zcorp.us/store/category.asp?Cguid={952080C5-8891-4E33-A58D-1F776958049F}&Category=ModelSupplies:Rubber

--Ates

[twospruces]

awesome, thanks!

Also, does anyone have a guide to selecting the thickness of rubber, to match plane and/or propeller? and how many loops?

There seems to be at least a bit of science there, of which I am in the dark on. It would seem like thicker rubber = more torque, and more loops = more torque (but maybe less winds).

Is it as simple as - more loops and or thicker rubber = more power (Ie torque x rpm for a given prop).

aside; seems like rubber bands still have a pretty decent power/weight ratio compared to batteries/electric (maybe the best)

thanks, Steve

[Wildpig]

Don Ross' book on Rubber Powered Airplanes has some information on selecting rubber size. I'm not certain if there is a specific formula or chart for selection.
As a general rule: large cross section rubber, such as 1/16 by 3/16 will give more power but shorter duration.
small cross section, 1/16 by 1/8 will give more duration but less power.
There are variables , such as motor length,prop pitch, and number of strands that will change initial power and duration.

Rubber motors probably have the advantage on initial power output per size but, obviously electric will always win for endurance.

If you are not sure, just experiment. Build a decent flying model,(Fairchild 24,Arrow, Javelin, Lancer,Porter, Beaver, etc.)and change rubber motor sizes, props, etc. Develop your own data.