Ducted extruder carriage for Rapman

thingiverse

Replacement for the acrylic single-head Rapman extruder carriage. This design incorporates a fan duct that more effectively cools the area being printed, reducing curling and melting. Also holds the extruder fastening bolts securely, without them loosening and turning like the standard ones frequently did on my Rapman. Added July 2014: a couple of modifications! bkt60a.stl is a bracket that bolts onto the top of the rear end of the extruder carriage that allows a 60mm fan to be mounted and pointed at the top of the hot end. On my printer, this has totally prevented the heatsoak problem causing PLA to jam the hot end. duct shield.stl is a simple shield that attaches to the main duct at the bottom, shielding the tip of the hot end from the airflow, thus improving temperature stability. Instructions Purchase a PC cooler fan designed to fit into an expansion card bracket - I used an Antec branded one but there are plenty of physically identical generic ones. Take the PC case bracket off the fan, and insert the fan into the upper piece and drill through to allow a bolt to secure the fan. Fix up the wiring by either replacing the Rapman fan power socket with a molex plug (what I did) or vice versa. Insert the extruder fastening bolts into the upper piece from underneath. A good friction fit is best; tightening a washer and nut on the opposide side will pull the bolt snug. If the bolt is loose, some tape will suffice - the act of installing the extruder will pull the bolts snug. After removing print support from the middle and lower pieces, glue them together using your favourite adhesive. I use brown shoe glue. Install using original extruder carriage hardware (you won't need all the bolts though) NB: ductl3.bfb.zip is sample output generated using KISSlicer, 0.2mm layers using PLA