Bondtech Direct Drive Dual Extruder [abandoned]

As of June 2019 I’m abandoning this project & there’s little chance I’ll come back to it. The Taz 5 just isn’t worth the time and cost it will take for this project on top of the numerous repairs I’ve had to perform on it. To really be happy with this machine I was looking at a new board, linear rails, a custom build plate, a build plate sheet, new lead screws, plus this mod. I’d rather invest in something with higher quality parts from the beginning to start with. Since everything I was looking at doing would basically turn it into a smaller Prusa style Railcore I’m probably going to get a Railcore kit in the future.

If anyone is interested in continuing the project let me know and I can provide the untested models I’ve designed so far.


Starting a new project using the Bondtech BMG-X2 extruder, Chimera+ hotend, and BLTouch. For now this thread will be pretty basic and I’ll update the OP as I work on the project. I’ll make replies to track progress and discuss issues and ideas.


  • Cooling solution
  • 3D model of BMG-X2
  • 3D model of Chimera+
  • 3D model of BLTouch

Still need:

  • Mount design (nearly complete)
  • Check if added 11mm to either side of mount affects print volume and what FW changes are needed
  • Wiring
  • Firmware
  • Required materials list
  • Instructions
  • Better part cooling?
  • Acquire parts
  • Test fit

Special thanks to:
marcio - base Lulzbot firmware used in this project
more to come…

Deleted, the forum didn’t like having two images in one post and freaked out

Here’s the mount by itself
I’m going to make the Bondtech mounts part of the extruder mount rather leaving them separate as seen above. This extends both sides of the extruder mount 11mm for a total added width of 22mm. I need to see if this will reduce the print volume or is there’s enough headroom to just change the offsets in FW.

Here’s what the full assembly looks like right now on the X carriage

Posting this on the forum encouraged me to do more work on this so I’ve merged the Bondtech mounts, relocated the BLTouch since the heater blocks were in the way, and rounded some edges. The left edge may need to be straightened back out for the X axis endstop

I haven’t been able to work on this any further because I’m trying to save money for bigger things not 3D printer related. I’m still looking for inspiration for better part cooling but nothing I’ve seen has sparked an idea yet. I want to get this project moving so I’m starting to do a few commissions for friends to raise money for this and other upgrades.

Just for a bit more of an update here’s my current list of things to get/do, this is not a complete list

Looks great!

Updated OP, I’m no longer moving forward with this project