Aluminium Prusa i3 X-Carriage for Chimera and 18mm Sensor

thingiverse

Using leftover 6mm aluminum from my frame, I built an all-metal X-carriage for my Prusa i3 to hold a Chimera dual-head bowden extruder and an 18mm diameter inductive proximity sensor for bed leveling. The 40mm fan duct blows from behind in a ring pattern, and I glued the two sections together with rubber cement type glue. This design works fairly well but obscures access/vision to the nozzles somewhat. To improve this, I created a simpler version called 'Fan Duct Lower V2,' which gives better vision. To attach this carriage firmly, I needed to install M3 helicoils into the mounting holes of the SC8uu. However, there is an issue with this design - the carriage heats up and causes the sensor to drift significantly. To combat this, I plan to add insulating washers to the sensor bracket or remake the sensor bracket from plastic. I cut metal parts on a 6090 router using a 3.175mm single flute bit. The grooves in the backplate are 2mm deep. Assembly involves drilling through the 3mm holes from the backplate into the extruder bracket and sensor bracket with a 2.4mm bit, then tapping to M3. Similarly, drill into the carriage web using M3 x 10-12mm screws for this purpose. To attach the SC8uu bearings, you need to drill and tap two on one side in the middle to hold the belt bracket (see photo). Use M4 x 10-12mm screws to hold the SC8uu bearings, with countersunk screws behind the Chimera. I drilled and tapped the set screw holes in the Chimera body through to the front, so I can adjust the nozzle heights easily by removing the 30mm fan. Print Settings: Printer Brand: RepRap Printer: Prusa i3 Rework 1.5 Rafts: No Supports: No Resolution: 0.20mm Infill: 50% Notes: The lower section of the fan duct prints OK without supports, which would be impossible to remove! Just rip out any saggy bridging filaments. Print the lower section with the open side facing up.