I'm assuming that the heli in question is a Kalk Alpha XII (called the Alpha 60), I've got the Kalt Baron XII (called the Baron 60) which is the same as the Alpha but it's a glow engine design not gasser... the collective linkage system has leverage built in to the design for use with a standard servo, they didn't have all these high torque versions to choose from many yrs ago when these helis were common place. mine is 10+ yrs old and has many thousands of hours on it and has always used a standard servo on all controls but the tail (high speed upgrade about 5 yrs ago, but still uses a JR NEJ 120 ball bearing gyro) and it's never had any problems with under torqued servo restrictions. granted this heli is for precision flight not aggressive 3D but it does fly better then even my X-Cell Pro Graphite.

kc