Tinkering
I’ve always been the type of person that loves to tinker. As a child it was Mecano or Lego Technic sets (as well as taking apart the odd VCR, sorry mom) and electronic kits to see how things worked. Now with small micro computers and logic controllers like the Raspberry Pi or Arduino the possibilities are endless. About two years ago I decided to convert one of my Prusa i3 MK3s from an 8bit machine to a 32bit machine. There had been many in the 3D printing community that had done this and I wanted my own chance to play with the advanced features it provided. I chose the BigTreeTech SKR 1.4 turbo as the main board for this project. It natively ran the Marlin 2.x firmware, more on that later, supported 5V, 12V and 24V components and removable stepper drivers. The Prusa’s Einsy main board has soldered in TMC2130 stepper drivers so being able to change them on the SKR was a big selling point for me.
Now, I know not everyone reading this will understand the technical side of things so I will do my best to explain what I am talking about here. The main board is the “brain” of the printer; it drives everything. It runs the firmware (or physical component software) that tells the printers various components what they are and what they can do. The Prusa’s Einsy main board is an 8bit board which, while it is perfect for a stock Prusa MK3, is not capable of the more complex calculations that the SKR 32bit board can do. This allows for more features and flexibility in the firmware. The stepper drivers are the control chips that tell the printer’s motors what to do. Stepper motors work exactly as the name implies, the motor shaft moves in steps as opposed to a standard electric motor where the shaft just spins when electricity is applied to it. Stepper motors allow a high degree of precision and are the muscles of the 3D printer. The main board, or brain, controls the stepper drivers which in turn control the number of ‘steps’ the motor takes when spinning the motor shaft. Having the higher powered 32bit main board allows more signals to be sent to the stepper drivers without the risk of data loss.
The Marlin 2.x firmware allows complete control over what the machine can do. There was a bit of a steep learning curve at first since I had never seen the back end of the code before but it didn’t take me long to find my rhythm and get features working. Even after two years my firmware is still very much a work in progress as I tweak things and add new features. Chris Warkocki of the 3D printing community was an extremely informative resource on programming Marlin for an SKR converted Prusa MK3. His videos provided the basis for my firmware. I spent hours tweaking how the printer performed functions (or didn’t function, if I incidentally set something up wrong) which was a valuable learning experience on the not often seen side of 3D printing.
All in all, I’ve been extremely happy with how my Prusa SKR MK3 works and in many ways works better than my Original Prusa MK3 (which is now a MKS+ after manufacturer upgrades). It’s fast, it’s quiet and supports some of the more advanced functions like S Curve Acceleration and Junction Deviation to improve the quality of my prints. I also recently updated all of its parts to ABS plastic which will make this printer more reliable in it’s enclosure for printing more advanced materials. There are still a lot of upgrades I would like to do to it, most notably changing out the stainless steel rods and linear bearings for high precision linear rails, but that will all come in time.
As I said, I am a tinkerer and will never stop tinkering!