Bondtech Extruders Do Wonders

Thank you Michael Hackney for recommending the Bondtech extruders. I’m able to power my high pressure e3d Cyclops hot end precisely w/ out slippage or grinding thanks to Bondtech extruders. According to an article I read about them the extruders use dual drive gears that clamp the filament from both sides to eliminate filament slippage and grinding with whatever hot end you use. Here’s an example of something I made with the extruders and the Cyclops hot end on my TAZ 4:

The Bondtech extruders are sold individually; however I’m running dual extruders with a custom mount that Martin, the owner of Bondtech, made specificially for the TAZ printers so they bolt right on. The mount can be ordered with the extruders. I decided to go with a bowden set up for my extruders to keep the load on the x-axis light, but the Bondtech’s can be direct drive mounted as well. Here’s my setup:

In case anyone’s interested here’s a link to the extruders on the Bondtech website:

Hey Invent,

I’m trying to convert a TAZ 5 with almost the same setup as you have on your Taz 4 with dual bondtech extruders and 2 E3D hotends or a Chimera. Can you give me any recommendations as far as settings go and what I’d need to modify on the printer. I’m just starting to get into it. Any help is greatly appreciated.


Hey ajp1976,

Here’s some information for you:

  1. Extruder Mount - You will need an extruder mount for the Chimera. Here is a pic of a design originally posted by mushoo that I modified so that I could mount the Chimera with the nozzle height adjustment screws facing out. I also added slots for bowden clips to eliminate movement of the bowden tube and added printable support so there is no need to ask the slicer for support; I added a few other mods as well. The stl’s of the mount and the bowden clips are attached. The two fans in the pic are blower style and purchased from Amazon (
  2. Bondtech Dual Extruders - The TAZ is dual extruder ready; however you’ll need to add a second extruder wire harness because it doesn’t come with it. I bought the Lulzbot Flexy Dually and it came with this harness. It’s easy enough to build one yourself and possibly Lulzbot sells it separately. I’m guessing it is configured the same as the stock extruder harness, but I would verify this. Here’s a pic of the second extruder wire harness (it’s the blue one) attached to the electronics box. Some of the wires will run to the 2nd Bondtech Extruder and some will run to the 2nd hotend. The way I configured it the 2nd extruder wire harness runs the hotend cooling fan and the original stock extruder wire harness runs the part cooling fan:

    Fortunately both the stock and 2nd extruder wire harnesses are long enough to reach the top mounted Bondtech Extruders. I had to splice the wires into the wire harness that comes w/ the Bondtechs; although last I checked I thought I remember seeing a TAZ compatable connector now available with the Bondtechs. Here’s a pic of the extruder wires running along the top of the TAZ frame and attached to the extruders:
  3. Firmware - I loaded the Marlin dual extruder firmware that Lulzbot had available at the time. I’d be happy to try to send it to you if you’d like. In the configuration.h tab the steps for the Bondtech extruders need to be set to 476.55. I believe here’s all the changes I made to the firmware, no warranty implied :slight_smile:

Change pins for extruder heater

Change thermistor for extruder heater:
#define TEMP_SENSOR_0 5
#define TEMP_SENSOR_1 5
#define TEMP_SENSOR_2 0

Change steps for extruder motors:
// default settings

#define DEFAULT_AXIS_STEPS_PER_UNIT {100.5,100.5,1600,476.55} // default steps per unit for TAZ {X,Y,Z,E}
#define DEFAULT_E1_STEPS_PER_UNIT 476.55 // default steps per unit for second extruder

Find the line #define EXTRUDER_0_AUTO_FAN_PIN EX_FAN_1 and set up fans so the extruder heat sink fan turns on automatically at 50C and if that fan is 12V set #define EXTRUDER_AUTO_FAN_SPEED 145 // == 1/2 speed (255 is full speed for 24V):

// Extruder Fan Setup
// If set to -1 all Extruder fans will be disabled
// If set to 1 only EX_FAN_0 will be used as a nozzle cooling fan for Extruder0
// If set to 2 EX_FAN_0 and EX_FAN_1 will be used as nozzle cooling fan and will switch between active nozzles
// If set to 3 EX_FAN_0 will be controlled by M106 S255 and EX_FAN_1 will be controled by M106 P1 S255
// If set to 4 EX_FAN_0 will be used as a nozzle cooling fan and EX_FAN_1 will be used as a heat sink fan
#define EX_FAN_0 FAN_PIN
#define EX_FAN_1 FAN1_PIN

// Extruder cooling fans
// Configure fan pin outputs to automatically turn on/off when the associated
// extruder temperature is above/below EXTRUDER_AUTO_FAN_TEMPERATURE.
// Multiple extruders can be assigned to the same pin in which case
// the fan will turn on when any selected extruder is above the threshold.
#define EXTRUDER_AUTO_FAN_SPEED 145 // == full speed

I would also refer to the dual extruder setup posted on Lulzbot’s website to glean additional information on the basics although keep in mind this is for their V2 hotends, not the Chimera or other style hotends ( As far as slicer settings, I can post those later. Hope this helps. Please let me know if you need any additional information.
Bowden Clips - Design 4.stl (10.6 KB)
Chimera + Fan Mount v2 - 20160510.stl (131 KB)

That’s awesome, thank you so much