Toybox Alpha 2 Large 1kg Spool Holder 608 Bearings or No Bearings

I designed a 1kg large spool holder for the Toybox Alpha 2 printer that can be printed on the Alpha 2 small bed size. After having a few spool holders break on me and not work great for cardboard rolls (stressing the extruder drive gear), I spent about 16 hours outrageously overengineering this bearing supported spool holder in the name of lower friction spinning, for those larger, 1kg filament rolls. STLs sliced with minimal supports but oriented horizontally where possible, specifically for strength with a 1kg spool. A few of the parts have high infill to make them robust and functional.

I used the toybox twist-lock interface for all the connection points, which seems to work pretty well. It is twist lock left AND right to connect and remove the spool holder. 

Could be adapted to other printers where necessary, if you can adjust the connection pin to fit. The new Elegoo Centauri Carbon comes to mind.

Everything is designed to be printed horizontally where possible, mainly for layer strength but also to fit on that printer! Print the 6 nub pin that connects to the printer at 100% infill for strength! The holy roller can also fit the toybox small rolls. 

NOTE: THE 608 BODY REQUIRES 608 BEARINGS to work. So be prepared to buy them or snag them from a skateboard :)

Alternatively, you can print the bearingless body, which does not require bearings and is hollow in the middle to reduce print time.

I have tested both:
The roller on the bearingless body spins with less resistance (flicking it with my fingers).
The roller on the 608 bearing body spins with more resistance, but the bearings are smoother rolling. 
If your filament is unwinding with extruder movement, try adding more bearings to 608 body (5), to tune the resistance.

You can even flip the 608 body to roll on 1 bearing, or can do 2 or 3 bearings on top to further reduce friction. Not all bearings are made equal, so higher quality ones will roll better, lower quality bearings you can use fewer of them to keep the rolling resistance low. Another thing I've tried is removing the Connecter plate between the body and the printer, to keep the roller loose. There will be a gap, but the connector pin is strong enough to handle it.

Standard PLA is fine, as long as you account for 100% infill on the small 6 nub connector. The whole point of printing this was to be able to use other 1kg filaments on the Alpha 2 printer, but… chicken before the egg… or is it the egg before the chicken??

This design is 100% my own EXCEPT for the Toybox Twist-Lock connection, which I had to use to adapt to their printers. 

Happy Printing!