Converting a 3D Printer into a Multi-Purpose Machine: PCB Mill or Jewelry Engraver

Introduction

Everyone needs engraving and 3D-printing tools, which are often trivially available through a hybrid 3D printer. However, it's important to consider the tools each product of such a printer has and how well they fit your needs. If you're curious about converting your 3D printer into a PCB mill or jewelry engraver, this guide will walk you through the process.

Technical Considerations and Challenges

Technically, the conversion is not too difficult. However, the tools you may end up with aren't as robust as a dedicated CNC milling machine. A better option is to build a machine designed for multiple purposes in the first place.

For instance, there are designs available online for multi-purpose machines like triple-purpose 3D printer/mill/laser cutter/engraving machine. This type of machine can be easily modified for various tasks, making it a versatile tool for your workshops.

This was the approach I took a couple of days ago. At the heart of the project is modifying the firmware to run without thermistor signals, as most 3D printers use Marlin or Sprinter firmware. I had to 3D print a custom spindle mount to accommodate the tool, and the standard G-code is often incompatible with tools like Repetier Host, which is not directly suited for CNC operations.

So far, I have a spindle that I can control in three axes, which could easily cut a PCB if I manually send G-code in the right format or write a formatter. I am in the process of swapping out my Ramps board for a GRBL board to improve the setup and ensure it works perfectly for milling tasks.

Physical Modifications and Strengthening the Machine

A mill has much more resistance than a 3D printer, and 3D printers are not usually designed for this type of resistance. For my project, I need to cut aluminum, which is quite ambitious. I am replacing many of the parts on my 3D printer and doubling the Z-axis rails. Additionally, I will likely need to upgrade my steppers before the project is complete.

Conceptually, these devices share a lot in common, and their controller electronics and software use the same G-code control language. What sets them apart is the physical modifications required to support material removal instead of adding it. This could be as simple as attaching a Dremel to your 3D printer. A laser could work as well, but a proper milling head for PCBs or other tasks tends to be heavier and places side loads on the axes, something the printer wasn't designed to handle.

Another important consideration is that a milling machine generates waste material, and most 3D printers aren't designed with this in mind. Make sure to protect the machine's delicate parts from flying debris or smoke generated by lasers.

Designing a Versatile Machine

Even with the challenges, you can certainly design a machine that can handle both activities. Use existing Reprap designs, and you can create a more compact or portable machine than two separate machines.

Conclusion

Converting your 3D printer into a multi-purpose machine like a PCB mill or jewelry engraver is a complex but rewarding project. With the right modifications and some additional hardware, you can expand the capabilities of your 3D printer and turn it into a powerful tool for various tasks. The key is to approach it with the right mindset and the willingness to make the necessary changes.