These are the parts needed to print a bobbin winder attachment for the EEW 6.0. Normally the EEW 6.0 spins fiber into yarn. However, if you remove the flyer and use this bobbin winder it allows you to quickly wind bobbins.

The only parts that need supports are the belt_holder_medium and belt_holder_fast.

See this video for more information: https://www.youtube.com/watch?v=D4GJt3Cpe00

In addition to the 3d printed parts you will need these:
1) 3/8 inch diameter rod: https://www.mcmaster.com/8920K135/
2) 6804-2RS, Bearing: https://www.mcmaster.com/5972K279/
3) R6-2RS Bearing - https://www.mcmaster.com/60355K703/

The 3/8 inch rod could be made out of many different materials like aluminum or steel. Just try to make sure it is 3/8 inch or smaller like the one linked above. I had to sand my rod to remove oxidation before the bearings would fit, but then it worked great.

There are much cheaper places to buy these bearings online, but the McMaster listing is likely to stick around and I really like all the extra information they put for their parts (I use them a lot for prototyping). Feel free to look around for other options for these bearings. Also EEW 6.0 comes with extras of the R6-2RS bearing so you might not need that one.