The future of desktop 3D printing - ASMBL™

The future of desktop 3D printing - ASMBL™

Welcome to the future

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Throwing back to our first ToolChanger & Motion System Blog Post in March 2018, it is fair to say the last few years has seen The ToolChanger & Motion System go through some lengthy research & development, culminating in an invaluable Beta testing program. Production began in 2019 and we have since delivered on the pre-order queue of over six hundred ToolChanger & Motion Systems.

With the production iteration of The ToolChanger & Motion System shipping for just over a year now, we’re seeing thriving communities (E3D’s Forum & Facebook Group) building around the Open Source ToolChanger ethos, plus a wide range of interesting tools developing alongside. Let us show you what some ToolChanger users have been upto - you won’t be disappointed!

First up is Chris Carragher’s Pick & Place tool. Chris worked at E3D as an engineering intern from 2017-2018 and built his final year thesis around his Pick & Place tool. 

Next up we have Nicholasav, a user on our forum, who is in the process of developing a pellet extruder tool with the hope of being able to use medical-grade polymers in his prints. We have also been busy developing a new exciting ASMBL tool, which we will go into more detail shortly.

Pellet Extruder
[Nicholasav’s Pellet Extruder Tool]

In addition to the tool development, we have seen ToolChanger users producing some amazing multi-material prints. Brendon Towers, more widely known as @brendonbuilds on Twitter, has printed many, many, cool and exciting parts for his Open R/C buggy, including studded tyres. He has also heavily modified and customised his ToolChanger - we highly recommend checking out his work.

[Brendon’s RC Buggy Prints]

Artist extraordinaire and ToolChanger connoisseur Louise Driggers takes full advantage of her ToolChanger by printing some of the most ethereal and detailed sculptures we have seen to date. Check out her work on MyMiniFactory

[Louise Driggers’ ToolChanger]

Tool-changing within FDM is a very new technology and there is still much more to be explored. One of our driving forces and a key part of The ToolChanger and Motion System specification is the ability to be inclusive of alternative manufacturing technologies. 

A big focus for us has been subtractive technologies and this is what we have been developing in the background to work alongside the ToolChanger & Motion System. We have named this technology Additive Subtractive Manufacturing By Layer, or ASMBL for short.

Additive & Subtractive Manufacturing By Layer (ASMBL)

Our vision of pairing Additive with Subtractive stems right back to the heady days of BigBox. When we first began working towards combining additive and subtractive technologies there were no slicers capable of integrating non-FDM tools into their workflow. Our early development and testing of ASMBL was achieved by massaging the Ooze Shield function in Simplify3D. Configuring the Ooze Shield to masquerade as a separate hotend (T1), in this case a dremel strapped to a modified BCN3D Sigma R17, we could attempt to mill the outside of a printed rectangle.

By trial and (lots of) error, we managed to print an additive layer and then immediately subtractively machine the same, just printed, layer, eventually building up a small rectangle on the Sigma. Early testing showed that subtractive was possible, even on a machine not designed for it, and with some minor adjustments it could make a big difference to the end results. 

[31st May 2016. The ASMBL acronym was first aired by Sanjay]

The next development iteration featured a BigBox with a newly designed IDEX system, which was made with a view to expanding ASMBL capability. Improvements included a stronger motion system and a stable, fixed spindle. The new spindle was capable of much higher speeds and had considerably less run-out than the Dremel.

[1st September 2016]

The S3D ooze shield could not perform top surfacing, or even mill internal edges. With the hardware improvements gained by the IDEX BigBox it was time for some software improvements. Alden, our intern at the time, wrote what was a basic CAM program which expanded on the ooze shield and also spliced in together S3D additive code. This advancement meant we could mill more complex parts and also introduced top surfacing to the process.

[12th November 2016]

When development of the ToolChanger & Motion System began in 2017 the knowledge gained from the early testing on the Sigma & BigBox defined part of the ToolChanger and Motion System specification. The precision and rigidity we wanted, and drove for, has a large part to do with our desire to mate the high precision of subtractive technologies with the geometric freedom of additive manufacturing.

[The bare Motion System frame]

The ASMBL™ Subtractive Tool

The ASMBL Subtractive Tool has been designed with a view to making ASMBL as accessible as possible. The tool uses the Blank Tool Plate & Dock Kit, a BLDC motor, ESC and an ER8 collet. All parts are easily available and can be controlled directly by the Duet2. A complete part listing, including STLs, is available on Thingiverse (

[The ASMBL Subtractive Tool, complete with vacuum chip extraction]

Fitted with a 2mm single flute end mill we have seen great results with ASA and PEEK materials. The addition of a vacuum chip extraction system, made from CPAP pipe, keeps the printer and build volume clean with only a small amount of debris present during operation. We have no doubt that with further experimentation and testing we’ll be able to mill most, if not all, materials currently available. Hopefully flexibles too. 

[A dual-material print using PEEK and CF-PEEK with external faces milled using the ASMBL tool]



Utilising capable milling CAM software was determined to be crucial in creating high quality parts. Since Fusion 360 is freely available to the hobbyist community and is a well featured CAM program, it was an ideal choice to use for the subtractive gcode generation. All that was required was to merge it with an additive gcode script.

[The plug-in is hosted on Andy Everitt’s GitHub at |]

The ASMBL script generation program went through many iterations, starting as a standalone program that merged a Simplify3d gcode file with one from Fusion 360. As we used the program more, Fusion were also beginning to release their FFF additive manufacturing capabilities so the logical jump was to fully integrate the program into Fusion. And thus the plugin was born.

[The ASMBL Subtractive Tool]

The capabilities of the plugin continued to grow, with additions for fully 3 dimensional (non planar) CAM operations and multiple subtractive tools being supported in a single print among many others. What we now have is a program that lets you generate a ASMBL gcode script completely in Fusion where everything the user does is on the model more STLs. 

However additive in Fusion is still fairly new and is nowhere near as developed as other slicers; because of this, full compatibility with external slicers has been maintained throughout the development process for those wanting to get a little fancier with the additive gcode.

[A time-lapse of an early test part]

ASMBL™ Features:

Milled Faces for Improved Surface Finish

Layer-line artifacts are removed and rough top surfaces are milled flat, creating a glass-like surface finish on both the side and top faces. This can also be applied to engineering grade thermoplastics such as PEEK, illustrated above.

Precise Part Accuracy

Each component is correctly machined to size with any out of tolerance material subtracted off during the ASMBL™ process.

Correctly Toleranced Holes

Perfectly sized and toleranced holes on parts provide for easy installation of components into your prints. Install parts into your prints such as bearings, sensors, and much more without having to post process your parts.

True square corners

Typically true square corners are not possible using standard FDM printing due to a combination of the shape of nozzle orifices, and die-swell. Using an ASMBL™ Tool, sharp corners can be manufactured even when printing with a large nozzle diameter.

Non-Planar Milling

Non-planar milling allows the “stair-case” layer effect, commonly found in FDM parts, to be a thing of the past; making parts that require less post processing.

The future of ASMBL

We are talking to the folks over at Autodesk, who are very interested in supporting ASMBL, with a view to improving Fusion 360 to be better able to integrate CAM and FDM G-Code generation. Our ASMBL plug-in will remain open source under a LGPL license and we hope to have an iterative app available for Fusion 360 to make both setting up and using ASMBL easier for the average user.

As with everything we have done thus far with The ToolChanger & Motion System, our intent is to advance the capabilities of FDM. ASMBL is another tool with great potential and something we hope you’ll pick up and run with.

ASMBL Subtractive Tool |

Fusion 360 Plug-In |

ToolChanger & Motion System |

E3D Forum |

Previous blogs

Research and Development: Motion System and ToolChanger - March 2018

Beta Testing Begins - August 2018

Beta Testing Update - January 2019

Pricing Breakdown - February 2019

Design Lock Reached - April 2019

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