Two Months with the E3D ToolChanger – Part 1

It has been a long time since my last article on but for good reason. I was lucky (and unlucky – more on this later) to be low in the ToolChanger queue and received mine shortly after they started shipping.

E3D, known mostly for their nozzles, announced a new motion system and ToolChanger design in March of 2018. With each trade show and meetup they attended where they showed off the ToolChanger the interest surged. E3D did not invent tool changing, but they managed to reduce the complexity and cost to a point where hobbiests could actually get their hands on one. This isn’t to say the system is inexpensive – it is not. Compared, however, to commercial/industrial system it is inexpensive.

E3D has stated they do not want to be in the business of creating printers. I think if you read this whole post you’ll get the sense that is still true. They want to great a system other manufacturers can adopt so they can sell more nozzles, and more recently, more extruders.

Who is the E3D ToolChanger for?

E3D initially stated that this was going to be bare bones system that would require additional parts to complete, but due to reasons unknown to me, they ended up offering a kit to build a complete printer. Despite this change I still urge people new to 3D Printing to find a more complete and better supported printer than the E3D ToolChanger.

So who should get a ToolChanger? Considering the hefty price tag of $3200+ US and the plethora of high quality printers out there for a lot less money you should only be considering the E3D ToolChanger if you meet many of the needs below:

  • Multi material printing beyond dual extrusion
  • Multi material printing where the materials you want to print with need different extruder settings (TPU + PLA for example)
  • Interest in tool heads that do not just print plastic (laser engraver, pick and place, camera/scanner, etc.)
  • A robust motion system that allows for speed and precision across multiple tool heads

Some of the downsides to getting the E3D ToolChanger right now include:

  • Assembly guide is still a work in progress
  • Despite profiles being available, a lot of tweaking is needed to get good prints
  • E3D continues to innovate so early adopters are not given the chance to select a newly announced Hermes (link goes to 3D Printing Nerd) direct drive solution for their ToolChanger
  • Firmware for the ToolChanger is still a work in progress
  • Some material and design choices could be improved
  • Minimal user base with experience running the ToolChanger

If you like to tinker, have a fair amount of 3D printing knowledge, and are looking to expand your printing capabilities then the ToolChanger might be something to consider.

Building the ToolChanger

Assuming you get the full kit that E3D offers, building the ToolChanger is fairly easy for anyone who has put together a Prusa MK2 or MK3 kit. The documentation has good pictures decent instruction with a few inconsistencies and some assumptions about your printer knowledge. By the time you get your hands on one I think the documentation will be even better.

I mentioned earlier that I was both lucky and unlucky to get the ToolChanger early. Unlucky because the instructions included guidance to use thread lock on almost all bolts, but as it turns out thread lock weakens certain plastics including plexiglas. E3D has updated their instruction and replaced plexiglas panels that were cracked for customers who followed the instructions.

Shows crack on plexiglas
Crack not from tightening but because the thread lock weakened the plastic

Aside from the above issue the rest of the build is fairly straight forward. The aluminum parts were well machined and cut. With the exception of a missing screw and a few confusing instructions I did not find assembly to be difficult. It is important to read the instructions carefully, but also read instructions for individual components like the Duet electronics and Titan extruders.

With the exception of the touch panel, brush, and filament, the final picture above is what you should expect from your ToolChanger complete kit:

  • 4 bowden V6 tools with brass 0.4 nozzles
  • 2 regular Titan extruders, 2 mirrored Titan extruders
  • Frame with plexiglas sides, screws, and misc parts
  • X, Y, and Z motion system that uses linear rails
  • ToolChanger coupler – the thing that makes all of this possible
  • Power supply, motors, wiring, and electronics

You will need to print all plastic parts except the V6 plastic docking part which is included:

  • Spool holders
  • Brush holder & brush
  • Cover for ToolChanger coupler
  • Motor wiring cover
  • Stress relief and wiring guides for all 4 tools plus ToolChanger coupler
  • Plexiglas hole covers and fan airflow guide
  • The 4 part cooling fan adapters
  • 5 frame mounted stress relief and wiring guides


There seem to be two strong opinions out there about Bowden setups. One is that any Bowden printer can produce quality and consistent results with enough tweaking. The other is Bowden printers are hard to work with and do not produce consistent results.

I know Bowden printers can print well. I’ve seen the results first hand and the reduced weight often means being able to print faster with less motion related artifacts like ghosting. That said the E3D ToolChanger Bowden needs tweaking. The provided profile for Simplify3D (S3D is not required, by the way) is really a starting point. The ToolChanger has long Bowden tubes (790mm) which, from what I’ve read, is close to the max length you want to go. Not only that, but the Bowden tubes are bent more than a typical Bowden setup.

With this Bowden setup I managed to get good simple prints. Others, in the E3D forum, have very good simple and complex prints. People who have had the beta kits the longest have amazing prints with the ToolChanger bowden setup.

I, on the other hand, struggled with complex Bowden prints. I put a lot of time into tweaking and adjusting settings, checking extrusion, and researching other Bowden settings.

I dialed in the standard 10×10 cube which is an easy print, but a good starting point. The first benchy after the cube was mediocre. There is a fair amount of stringing even with high retraction of 4.8 and there are clearly some retraction related issues on the arch and smokestack. The retraction issues largely were a result of the profile setting in Simplify3D set to retract more often than needed.

First benchy print

After more tweaking including reducing how many retraction occurred during the print, I managed to get a decent but not amazing rhino print. Stringing was reduced and small details printed better like the horn and ears. There are clearly still retraction issues however.

Rhino print

I tried a lot of settings to get the prints coming out better including flow rate, adjusting retraction distance, temperature, speed, a brief very unsuccessful attempt at turning on pressure advance, and any other settings I thought could contribute to the print quality. The above Rhino was still about the best I could get.

I decided, begrudgingly, that I am spoiled by my Prusa MK2 and MK3 direct drive printers which produce very good results with minimal tweaking. As my patience was wearing thin and I thought, instead of trying to get the Bowden printer working perfectly, especially knowing that Bowden printers are usually fairly poor at printing flexible filament no matter how well tuned they are, I decided to look into designing a (nearly) direct drive extruder for the ToolChanger.

Check back for part 2 where I design a new extruder and make other modifications to the ToolChanger as well as show some multi-tool prints.

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Building the Prusa i3 MK3

My previous experience putting together 3D printer kits has included splicing wire, soldering, adjusting potentiometers, cutting and drilling parts, and even building small circuit boards.

The Prusa i3 MK3 kit suffers from none of the above. It is a well designed kit that I would compare to building a complex lego set. This is helped by a detailed manual (both printed and digital), properly labeled bags, community discussion, videos, and hundreds of hours of testing.

If you are confident you can properly connect negative and positive wires to the correct terminals and follow a visual guide showing you where and how to connect pre-made wires, then recheck everything, I believe this kit isn’t as hard as it might seem on the surface. With a few tips I think most people, who can handle the above, can easily put together the i3 MK3 kit.


  • Expect to spend 4-8 hours building the kit.
  • Always read the instructions first before starting. They often include important build instructions that help you understand why you are performing the tasks.
  • I highly recommend using a torque controlled screw driver designed for electronics/delicate-parts and set it to the lowest torque setting. Allen keys are too easy to over tighten and you can end up with cracked parts. I know this is an added expense, but that tool will come in handy in the future so it is not a lost investment.
  • Before you let loose with the power screw driver or even the Allen keys I would hand start any screws to make sure they catch appropriately. This will prevent binding and stripping of threads.
  • Triple check the power supply and bed wires. One of the few things that cannot be fixed is powering up the printer with it incorrectly wired for power.
  • The P.I.N.D.A. probe should be very close to the surface of the print bed while the nozzle is touching. Setting the P.I.N.D.A. too high will result in the nozzle possibly crashing into the bed. The manual recommends using the thick part of the zip tie, however I used the thiner part of the zip tie instead based on my experience with the P.I.N.D.A. probe on the Prusa i3 Mk2.
  • Use the online manual if the print manual images are not clear. I found this particularly helpful for the E Axis and E Axis wire strain relief.
  • A majority of screws and parts are color coded in the manual. The manual will show, for example, a screw boxed in orange then often an orange arrow or box where the screw goes and finally an orange bullet marking in the text that refers to this part and screw.


Aside from using the occasional wrong screw I did run into two significant issues that you might be able to avoid.

In the right Z part you need to insert a nut into a hard-to-access slot. Unlike other places in the manual where you can essentially pre-seat the nut, this is not possible (see the blue box below).

Right Z nut placement

When trying to insert the screw it ended up binding and I was not able to either reverse the screw or tighten it. The nut would spin and even with significant force trying to hold the screw in place I could not dislodge the two. I did this without the trapezoidal nut installed because I was trying to align the nut and screw. The trapezoidal nut cannot be attached due to the screw head. The solution, for me, was to cut the screw head off:

Z nut fix

The printer works in this setup, however I will print a replacement right Z part to have the trapezoidal nut properly secured.

The second issue I had involved the calibration wizard. I was getting self test error “X-Axis Length” which essentially means the printer is not returning the expected length of the X axis. Often wires or zip ties can cause this, but in my case the Z was misaligned enough that there was minimal binding stopping the X from moving the full distance. To solve this you can exit the setup wizard do a quick Z calibration. Once that was done the self tests all passed in the wizard.

I hope to put up a review of the Prusa i3 MK3 in the next month or so.