Omni wheels positioning

[Jak24]

Hi!

For my next robot i want to build a 4(omni wheeled) robot,
I have read that the optimum angle would be 90 degrees between each other,
But i also have read about different angles that you can use such as:
75 115 75 115 and many other
My question is which position would be the best?
As i would like to use the 75 115 75 115 position, but in which postion would i have the least losses
from friction, efficiency etc...?

Thanks
Regards

Jak24
 

[rbtying]

Take a look at this http://www.societyofrobots.com/robot_omni_wheel.shtml#3vs4.  4 wheels in a 90degree configuration is the most efficient method.