ERCF V2 selector mod for larger 28mm (17g) servo Version2

## New changes in Version2 (this version) VS version1 

(Version 1 https://www.printables.com/model/971423-ercf-v2-selector-mod-for-larger-28mm-17g-servo  

 * In version1 servo arm cannot touch the filament block top hat to release brake. The work around for ver1 is to remove the brake nut screw and file the brake part hole larger.
 * In version2 , move the whole selector part to left about 5mm, so it has enough room for 28mm servo, the servo arm is in the same place as the 23mm servo in original design.
 * since the 28mm servo is in the same place as 23mm orig servo, it now can touch the filament block top hats, this can release the break, to let filament freely move. 
 * since the whole selector part is 5mm lefter, the encoder case right half need to be longer to reach the selector output hole.
 * other than the brake release, there is no other significant benefit using version2. if you don't like the brake at all , version 1 is good enough, just remove the brake.
 * For people using EREC filament cutter mod, like me, the encoder case right half mod is provided. since the encoder must have a longer input hole to reach the filament block.
 * stronger front mount holes for EREC cutter. use 25mm M3 screw for EREC filament cutter beta 7 (my mod only)

more info please refer to Version1

https://www.printables.com/model/971423-ercf-v2-selector-mod-for-larger-28mm-17g-servo

works with EREC cutter beta7

https://github.com/kevinakasam/ERCF_Filament_Cutter

This works better for EREC Cutter Beta7 MOD (my version of mod)

See attached picture, ERCF EREC Cutter Beta 7 MOD is installed

Software config

because now the selector part is about 5mm lefter, need to change mmu_parameters.cfg file

gate_parking_distance was 8, need to change it to 14, or try and adjust

gate_parking_distance: 14.0   # 8 old. OK Parking position in the gate (distance back from gate endstop/encoder point)