Mini Kossel 3D Printer

This 3D printer is based on the open source RepRap Mini Kossel design. Most of the parts were sourced from various places around the internet (Some of the parts on the current iteration were fabricated with the machine itself.)  

(From left to right: build-in-progress, first iteration, current iteration)

The unmodified Mini Kossel design uses a spring-loaded probe for automatically tramming the build platform. This works fairly well, but the probe is offset from the printer's nozzle, and the micro switch does not always trigger at the same height.

The open source 3D printing community developed another probe design that remedies these issues - force-sensing resistors (FSRs) underneath the build platform. With this design, the probe is the printer's nozzle itself, and a microcontroller monitors for changes in force, which triggers far more consistently. I modified a bed mount to fit the FSRs and printed it on the Mini Kossel.

My Mini Kossel is controlled by an Arduino Mega 2560 with a RAMPS 1.4 shield. In order to enable printing while not connected to a computer, I added a RepRapDiscount LCD controller, which can read print files from an SD card. At the time, there were no minimal mounts that I could download and 3D print, so I designed my own using CAD.

When printing with certain types of materials, it is important to have sufficient cooling airflow across the part that is being fabricated. Many printer designs use common axial computer cooling fans. However, I have found that these fans are not always capable of producing enough airflow, so I decided to use radial blower fans. Like the LCD controller, I could not find any mounts that I could download and 3D print, so I designed some of my own.