Prusa USS Drybox - Installation on MK4/3.9 series

This guide describes how to install the Prusa USS Drybox on Prusa MK4/S and MK3.9/S

The Drybox is not compatible with MK printers installed in the Enclosure or with the MK3/S/+

All supported MK printers use the same Drybox mounting principle with a printed adapter, dual puck system, and direct PTFE routing to the extruder.

This guide covers adapter assembly, Drybox mounting, and PTFE connection to the extruder.

1. Prepare two pucks by placing two M4x6 screws on their flat part.

2. Thread an M3x18 screw until the middle of the spacer, and insert it into the middle opening of the adapter.

3. Join the adapter and the puck as shown below using another M3x18 screw. Use the side of the adapter that does not contain the screw from the previous step.

4. Turn the adapter over and unscrew the screw from the nut in the adapter.

5.  Remove the spoolholder from the printer and prepare it with the adapter and puck. Insert the spool holder into the adapter. It is important to keep the correct orientation. 

6. Screw a puck onto the other side of the adapter.

7. Screw an M5-4 fitting to the top of the extruder. 

8. Install the complete spool holder with the adapters onto the printer.

9. Place the drybox in the puck, and lock it with the removable spoolholder. Ensure that the seal is installed on the removable spool holder.

10. Load the filament inside the drybox, and insert the PTFE tube into the fitting.