R/C transmitter Gimbal

I'm keeping Futaba Transmitters, 18MZ, 14SG and 10J, so it is possible to compare their functions each other actually. The function on the Gimbal stick is the first difference on slipping resistor, very precisely different but it affect on the flight as a matter of fact. Especially, such kind of resistor is produced in 1 to 2 mm distance  movement  on the surfaces of self returning lever and guiding pin.
High end model has ball bearings at the rotating axial portions and the constructive designing takes effect, with just smooth movement in the Gimbal construction.
As a trial experiment, applied I 5-2-3 ball bearings on the guiding pin, then I found out that the movement in the Gimbal has far improved unexpectedly, the smoothness of 10J model is comparable with 14 SG or more.
So I conclude that the criminal to produce some bad feeling on the Gimbal construction dose not exist in the axial movement in the volume extension, but does on the slipping surfaces between self returning lever and it's guiding pins.
Controlling stick collapsing phenomena appears if ball bearings are applied as a matter of fact, it's means that the renewal and redesigning of self neutral guiding lever dimension should be done.
Also, one lever and two guiding pins designing produces the spring strength differences, one side lighter and the other heavier.
In case of two levers binding and single lever guiding pin designing does not matter on the directional movement.
I just remembered the scenery when I disassembled Leica M3 range finder camera few years ago. When I applied some lubricant on the shutter trigger portion, no oil and Microflon material was acceptable but Carbon-Led powder. The point that the slipping surfaces with relatively high pressure exists, only carbon powder with Led material is effective to reduce the slipping resister.
I'm going to apply the graphite material on the Gimbal construction after removing grease oil put by the factory, bad feeling would disappear, so I hope.
The resulting report later.