Dual E3D Extruder with servo

thingiverse

180801: I have made a couple of small design changes that are cosmetic so the images might be a little different than the stl-files are. I have made a couple of dual extruder versions earlier for the Creality CR-10 but it's always something that can be made better. In this case I wanted to get rid of the painstaking alignment of the extruders Z height so the nozzles don't scrape in the previously made layers. Hence a servo that lifts the second extruder. The cooling duct is made to blow from two directions to cool mere evenly. The servo is THX900 size and has an excenter mounted to the shaft. Mount it so that it is at it highest point when the extruder is up. Then the need to have power to the servo at all time is unnecessary since it can't be moved by the springs in that position. Two M3 holes or similar size has to be drilled and tapped in the mounting plate of the printer. One can also use screw and nut if one doesn't have any tap. Two springs is used to push the extruder carrier down but they are not weird in any way so it should be easy to find some suitable ones. I use one M3 nut for the BLTouch bracket and one M4 for the part fan. These are not the standard type but inserts that is melted in the holes with an soldering iron. See picture of example how they might look. The two metal sliders that the extruder carrier slides on are 3 mm in diam. It should be made in HIPS or similar that is more heat resistent than PLA. I have tested with PLA and it works a while but gets deformed and brittle by time. Also, the cooling duct was made for my clone E3Ds and the height might be wrong. There is a variant of the file where one can cut of the excess height of the throat before it is glued to the fan. This one should cover most E3Ds. In marlin some changes has to be made in the config file. The // in front of the code is just there so the text doesn't get super big here in Thingiverse, do not add them! //#define SWITCHING_NOZZLE //#if ENABLED(SWITCHING_NOZZLE) //#define SWITCHING_NOZZLE_SERVO_NR 1 (0 or 1 depending on how many servos you have. I have an BLTouch Probe that act as an servo and that is servo 0 for me) //#define SWITCHING_NOZZLE_SERVO_ANGLES { 90, 0 } // Angles for E0, E1 //#define HOTEND_OFFSET_Z { 0.0, 2.0 } (the offset has to be measured after installation and is just set as -2 as an example here) //#endif //#define NUM_SERVOS 2 (Total number of servos including BLTouch probe if present) //#define SERVO_DELAY { 0, 300 } (ad delay for both servos, and in this case 0 delay for my BLTouch but 300 for the extruder servo) //#define DEACTIVATE_SERVOS_AFTER_MOVE