Y axis C Beams (start)

First attach the nut holder to the metal ballscrew nut

Important: NEVER remove the ballscrew nut from the screw! There are tiny little metal balls that will fall out and that are impossible to put correctly in again – it will require to buy and ship a new ballscrew nut

Use M4 screws to hold the ballscrew nut well in the nut holder

Now attach these on the Y plates that you assembled earlier with 20mm screws. The picture here shows it with the inner plate and the wheels removed:

Now also add the ballscrews and the 10mm diameter side at the side where you want to have the motors (most people choose the backside for this)

At the 10mm diameter side, already attach the Y end plate – use 4 low profile 15mm screws for that – and with the direction in such a way so that you can fit a bearing in it from the outside. Already add the 8mm ID 16mm OD bearing: