Dual Drive extruder

THIS IS WORKING PROGRESS MODEL, Printing is not recommended

I am thinking of making 1:1 ratio Dual Drive extruder
I need help checking if this design would work and if there anything that needed to be changed



Parts that needed to assemble this extruder (not finished)
>M5 hex bolt x2
>Bearings 5x10x4 mm x4
>MK8 1.75mm Filament drive pulley x2
>Springs x2?
>M4 x 40mm bolt for spring


Any help would be most welcome (pls comment any ideas you have)

edit: 29/01/2018:
added