Fresh Chimera Build


So, I got the Chimera modification working. I used a geared extruder design based on the b-struder that mounts to t-channel.

They were fiddly to assemble but seem to be working reliably.
It took some digging to find all the changes to Marlin needed. In fact it took digging in several places to find everything.
I was surprised there wasn’t a complete howto somewhere.

I’ll post the firmware changes I made here in hopes that someone will benefit.
The first print is in the pics and shows the lack of tuning to deal w/the ooze. I’ve also got to add a nozzle fan and clean up the wiring some. It even was able to retain the Wilson 2 bed-leveling system which stuck down too far for the Chimera mount I used. You will see in the pics how I delt with it for now.
8 new photos by Randy Fountain

Wilson 2 firmware edits for Chimera
(Line numbers are approximate)


Line 146:
// This defines the number of extruders
// :[1, 2, 3, 4]
#define EXTRUDERS 1 << 2

Line 253:
#define TEMP_SENSOR_0 5
#define TEMP_SENSOR_1 0 << 5
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_3 0
#define TEMP_SENSOR_BED 60

Line 404:
Uncomment >>//#define THERMAL_PROTECTION_HOTENDS // Enable thermal protection for all extruders
^^ stops cryptic compile error

Using geared extruder and MK7.
#define DEFAULT_AXIS_STEPS_PER_UNIT { 80, 80, 400, 107 }

#define DEFAULT_AXIS_STEPS_PER_UNIT { 80, 80, 400, 504}

Line 82:
#define E0_STEP_PIN 67
#define E0_DIR_PIN 24
#define E0_ENABLE_PIN 26
#define E1_STEP_PIN 68
#define E1_DIR_PIN 28
#define E1_ENABLE_PIN 27

#define TEMP_1_PIN 10
#define TEMP_BED_PIN 10 << 11
#define TEMP_2_PIN 11

Set the offset in the slicer. Changing this line had no effect:
#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on
the X axis