Dual Dragon/V6 Ender 3 DirectDrive Project by undeliverable

Last crawled date: 3 years, 3 months ago

WORK STILL IN PROGRESS. At this stage I make no promises it will work.
REQUIRES the 4-wheel X carriage! The mounting plate will not match the stock plate!
This is a remix of eschmidt12's "BMG-X2 Chimera Creality Ender 5 Extruder Mount" remixed to fit a Left and Right BMG geared extruder and 2 Phaetus Dragon hotends (Im guessing the V6 will also work since they blatantly copied much of the V6).
The original is here :https://www.thingiverse.com/thing:4534090/files
This tool cooling shroud seems to work :https://www.thingiverse.com/thing:2089094
First print went pretty well. For a while. Then my SKR 1.3 proved it cant keep a stable temp on both hotends it seems. I did pid tuning but the second extruder is all over the map. Going to add a capacitor to the 5v rail and swap thermistors to see if that solves it. My switch out the MOSFET driving the second heater as well.
Nozzle alignment is tricky. I need to come up with some way of making them +/- .001mm of one another. A servo will probably be introduced at some point. Some of this I solved by staggering the bolts through the extruders, Using 1 50mm, 1 55mm and 1 60mm bolt per extruder allows for better stability. (Pairing the 50mm and 60mm bolts anchors both extruders together)
Test run on heaters and extruders worked well with minimal thermal bleeding between heads.
Custom printer profile is complete as well. Lots of edits needed in Cura to get dual extrusion running with full materials/nozzle/profile support. I think most of the main things are complete and I will run a calibration block tonight to fine tune offsets.
Engineering build has been assembled. Wiring is complete. Software has been updated. My SKR 1.3 needed more variables added to its pins file for the second extruder for some reason. This seems like a pretty big oversight on BTT's part since there are two extruder ports on the board.

#define E1_STEP_PIN P0_01
#define E1_DIR_PIN P0_00
#define E1_ENABLE_PIN P0_10
#ifndef E1_CS_PIN
#define E1_CS_PIN P1_01
#endif
Configuration.h offsets for the heads:

#define HOTEND_OFFSET_X { 0.0, 23.00 } // (mm) relative X-offset for each nozzle
#define HOTEND_OFFSET_Y { 0.0, 0.00 } // (mm) relative Y-offset for each nozzle
#define HOTEND_OFFSET_Z { 0.0, 0.00 } // (mm) relative Z-offset for each nozzle
probe offsets :

#define NOZZLE_TO_PROBE_OFFSET {-39.25, 6, -2 } // Example "2"
Lost build area after relocating the X endstop is 11mm, taking the bed to 224 x 235 x 250 (Staggered left/right for each respective head), or 213 x 235 x 250 for both heads.
The Left/Right extruder setup requires the left stepper to be inverted, in my case I decided that the left hot end was E0 :

#define INVERT_E0_DIR false
#define INVERT_E1_DIR true
Runout distance set to 145mm and will be tuned more later.
Stealthchop off for both extruders. Runout sensors on Z and Y max. BLTouch is currently on Servo, but may be moved to AUX or Z max to allow NeoPixel LEDs to be driven off of the SERVO connections. Or SERVO will drive actual servos if I end up needing head retraction.
I this build uses the CTree 4-wheel X carriage! The spacing for the caster bolts probably wont work for the stock carriage.
Also required are :
2 pancake stepper motors
12 M3 3x3mm threaded inserts
6 55mm M5 bolts
2 5015 fans
1 40mm fan
Once my build is complete I will post photos and setup instructions.