Ramps 1.4 Prusa MK2S Clone plus Linear Advance Firmware

thingiverse

Please consider a small donation if you find this design useful. I originally built a clone i3 MK2S while waiting for my genuine MK2S to arrive. As I could not obtain a Mini Rambo board at the time, I chose to build the clone around the popular Arduino/Ramps1.4 combination. As I wanted to use the Hictop 275x220 3mm aluminum heated bed, I also chose to go with 24V - something I have never regretted (quieter steppers and lower currents). As all the Prusa MK2S parts are freely available under the GNU license, it was easy to modify parts to fit the clone. My first clone was soon up and running the latest Marlin firmware, and it worked extremely well. Note that all the other printable parts required to complete this printer can be found on the Prusa website. When my genuine MK2S arrived, I soon realized that the Prusa firmware contained a lot of very user-friendly modifications like Z calibration; live Z; and filament load/unload. These changes, along with my software engineering background, and the fact that the firmware source code is freely available, I set about modifying the Prusa firmware to work on the Mega2560/Ramps1.4 board. I had some clues that it could be done quite easily from other posts, and TBH it was not that difficult, and within a few nights, I had managed to get the clone printer running the latest 3.0.12 firmware. Note that I have used a fan extender to add software-controlled case and hotend cooling fans. You can skip this and just connect the fans straight to the power connector if you are happy for them to be on all the time. I am in the process of writing a HOWTO, but in the meantime, I have posted a file for you to try. Use the standard Prusa firmware updater to upload the hex file. You can find this file on the Prusa website. The specs for these hex files are: File: i3Ramps-3.0.12-A.hex Name: "i3 MK2 Ramps" Mode: Dual Z steppers (on Z and E1) Steps-per-mm (X,Y,Z,E): 100, 100, 800, 143.5 Board: Ramps 1.4/Arduino MEGA 2560 X Limits: MIN Active HIGH, -2 to 212 (offset is to allow X to clear fan on controller) Y Limits: MIN Active HIGH, -5 to 230 Z limits: MIN Active LOW, 0.15 to 210 (sensor is NPN bed level sensor). File: i3Ramps-3.0.12-B.hex As "A" above, but with Z limit active HIGH for normal Z limit switch. File: Ramps-3.1.0-RC2-A.hex and Ramps-3.1.0-RC2-B.hex The latest release candidate with Linear Advance. All hex files assume type 5 hotend thermistor (E3dv6), and type 1 bed thermistor. Please note that you use these files completely at your own risk. Especially note that if your printer's dimensions are not the same as mine, the limits may not work properly. If your Z is smaller than 210, then the nozzle will crash into the bed when calibrating Z - you have been warned - protect the bed when you first try calibration. Finally, remember that these modifications could only be made due to the GPL nature of the Prusa printer. Please consider buying at least one printer from Prusa, to thank them for all their hard work.