A8 AM8 Extruder Spring Shim

This is a remix of https://www.thingiverse.com/thing:2274064 . Thanks for the great idea!

My remix addresses bowden setups using the original A8 extruder motor parts (pulley, idler).
If the spring is too weak to drive the filament constantly, try this mod.
The difference to the original is a slightly bigger size and a 4.5mm hole on the back to get a stable connection to the allen screw.