Anti oozing Dual Hotends for Rebel II 3D printer

thingiverse

This extruder is based on one guy's design from the Rebel II forum, inspired by a thread started there. The original design used direct-driven extrusion, but I didn't like that approach because it would have required rebuilding half of my printer. Instead, I chose to use bowdens and mount the extruders on the construction itself. You can use any bowden extruder you prefer for this project. The dual hot ends were designed with my Rebel II printer in mind, specifically www.rebelove.org, and also compatible with normal 3Draty hotends at www.3draty.cz. However, the design can be easily adapted to other printers (for instance Prusa I3) and different hotends (a version for e3d v6 is planned). The idea behind this design revolves around rotating the inactive hot end out of the bed using a servo motor and covering it with a metal sheet to prevent any oozing. Advantages of this design include: 1. No messy dual prints anymore - no more oozing from the inactive hot end. 2. No need for pillars or anti-oozing walls. 3. Standard hot ends can be used without requiring bowden versions. 4. Relatively easy to install and also easy to reverse if you don't like it. 5. Easy to build additional CNC devices based on 3D printing technology. 6. Every cable has a connector directly attached to the hot end. 7. Cable chain is already prepared for use. 8. Preparation for lighting up the hot end area with LEDs. Disadvantages of this design are: 1. Bowdens, in my opinion, aren't as effective as direct-driven extruders. 2. You'll need one extra motor - just an additional cost to consider. 3. Printing area is a little bit smaller due to the extruder's design. The servo used for this project is EMAX ES3104 or similar models, priced around 6 euros. The nozzles cover was cut and bent from 0.5mm aluminum using an attached drawing. For fan regulation, I utilized a circuit found at www.thingiverse.com/thing:22202. However, to get it working correctly, I had to set up the software PWM in Marlin's configuration - not entirely sure why it didn't work out of the box, possibly related to FET speed. You'll need plenty of bolts and nuts to keep everything securely in place, including M3 bolts of different sizes and 4 longer M2 bolts. Additionally, you'll require 4 bearings with a diameter of 1cm. Marlin firmware adjustments: In Marlin_main.cpp around row 3742, numbers 25 and 160 represent servo angles that need to be manually adjusted to find the correct settings for your printer's configuration. Please note: Ensure that the servo is set up to turn back to its original position consistently; otherwise, issues may arise with the X-axis. ....... else if (code_seen('T')) { tmp_extruder = code_value(); // Correction for servo Tools T0 a T1 even if they are not defined if (tmp_extruder == 0) { SERIAL_ECHO_START; SERIAL_ECHOLN("T0 Servo 25"); servos[0].attach(SERVO0_PIN); servos[0].write(25); delay(600); servos[0].detach(); } if (tmp_extruder == 1) { servos[0].attach(SERVO0_PIN); SERIAL_ECHOLN("T1 Servo 160"); servos[0].write(160); delay(600); servos[0].detach(); } // End of code A short video of the printer in action is available at https://www.youtube.com/watch?v=hTZHVi6KvII. A picture of a dual-printed octopus is also attached. Print settings: Printer: Rebel II Rafts: No Resolution: 0.2mm Infill: 20%