Dondolo modified arms remix

This is my personal contribution to Dondolo project.

Recently I had some extruder issues with original pieces, after many prints they started to miss some filament and I had to remove 3 spring coils to give more strength.
Since I like bearing version I added a spring tensioner to that version.

BOM:
- 1 M3x16 button head socket (DIN 7380)
- 3 M3 nut (DIN 934)
- 1 M3 nylock nut (DIN 985/ISO 7040
- 1 M3 Eye bolts
- 1 M3 washer (DIN 125/ISO 7089)
- 1 M3 wingnut
- 2 M3x14 socket cap (DIN 912/ISO 4762)
- 2 623ZZ bearings