Where did you get that Rotamax coupling?  Who makes them?

  Steve Brazil

  That is a German product Steve.
  Here is the web site http://www.centa.info/

  Here is the coupling used on the Rotamax.

  Paul Lamar


 Sorry for earlier message . Have a look at www.pegasusautoracing.com
part
 #
 1470 HD $149.99

 Peter Whitehead

This coupling seems to be a different design from what Rotamax is
using. I
am using this design in my single rotor. It came with the redrive from
Hirth. I believe it is made in Italy.

Has been holding up so far up to 6200 RPM under power.

 Richard Sohn
N2071U

Hi Guys;

There are a ton of these available.
Do a google search on the words "Guibo" and "BMW".  Several other car
manufacturers use similar donut designs.
There are also engineered equivalents for industrial equipment with
engineering design data.

Cheers
Cary