The frame is from a CubeX Duo (one of three donated by Mojo Coworking). The printer ran on proprietary hardware and software and was difficult and expensive to maintain, so we decided to convert it to an opensource machine. The hardware was replaced with an Arduino Mega and a RAMPS 1.4 board. The firmware is Marlin. We also replaced the extruder, hot-end, and z-axis endstop, and added a heated bed.

The control software on the laptop is Repetier using Cura as the slicer.

NOTE: If you are new to 3D printing, you should start with the TAZ6 printer. This machine will be easier to use, and we are continuing to dial in the best parameters for the RAMPS machine.

• This is an open source printer. Pay close attention to watch for any problems and turn off the printer immediately if you see a problem and report it.
• NEVER LEAVE THIS PRINTER UNATTENDED! While we are testing the printer, you must remain at the makerspace whenever using this printer to reduce risk of fire. You may prefer to use the TAZ6 for larger prints for this reason.
• Examine the printer before each use. If it does not appear to be in safe working order, place a sign on the printer, report the issue, and do not use the printer. If you are unable to determine whether the printer is in safe working order, or if you are unsure how to use the printer, ask someone for help.

1. Power on the laptop and open Repetier_Host from the Desktop.
2. To turn on the 3D printer, flip the switch connecting the black and green wires glued to the top of the power supply. DANGER: The heated bed uses 120V AC power, which is connected through the small board at the bottom center of the printer. Be very careful when reaching inside the printer not to touch any wires. If the switch has come unglued from the top of the power supply, do NOT reach into the wires at the bottom to retrieve it without ensuring BOTH power cords are unplugged. Notify a board member immediately if the power switch has come unglued from the top of the power supply.
3. In the upper left corner of Repetier, click the arrow next to the Connect button and select the RepRap_Marlin machine. The button should change to a Disconnect button once connected. If the button says Disconnect when you open the laptop, the laptop is already connected to the printer.
4. Load an .stl file using the Load button. An image of your piece should appear in the 3D View tab. you can manipulate the object using the Object Placement tab on the right side of the screen.
5. On the right side of the screen, select the slicer tab. The slicer should be CuraEngine, the Print_Configuration should be Slower_Speeds, the Speed slider should be set to Slow, and the Filament Setting for Extruder 1 should be PLA. As we use the printer and get other types of filament, some of these may change, but initially, these setting seem to give fairly good results.
6. When you have selected the correct profiles and entered your settings, click on Slice with Cura Engine. You should then see an image of what your piece will look like on the printer.
7. If everything looks good, click on Print.
8. When your print is done, wait for the bed to cool down. Then remove your print, turn off the printer using the switch connecting the green and black wires on top of the power supply, and close the laptop.
9. Please report any problems or desired changes to the profiles to any board member.

Currently, we only have PLA filament for this printer. If you use a different type of filament, you may need to create a new profile for that filament. If you are unsure of how to do this, ask for help. To change the filament, go to the Manual Control tab in Repetier after powering on the printer and connecting to it (see the Usage Instructions). Heat the extruder to 200 degrees and use the retraction button icon to remove the filament from the extruder. At this point, you should be able to remove the filament without resistance. If there is resistance on the filament, continue to use the retraction button to back the filament out of the extruder. To insert new filament, first use your hands to straighten about 6 inches of the new filament as much as possible. This is critical! Then, feed the filament into the extruder until it is resting on the extruder gear (this is hard to see, but looking in from the side of the extruder (front of the printer) can help. Once you think you have it positioned properly, use the extraction button to begin pulling the filament into the extruder. Continue watching to make sure the filament feeds properly into the hot end. If you are unable to get the filament to feed properly, try straightening it more with you hands. As a last resort, you can remove the fan and metal plate covering the extruder and position the filament inside the extruder manually. Be careful when doing this not to put too much stress on the fan or bed leveling sensor wires and to put everything back properly.

We have several differently sized nozzles for the hot end. Initially, the 0.4mm nozzle is installed and the Repetier profiles are set for this. If you need/want to change the nozzle, please contact a board member.

A schematic for the heated bed relay board can be found here. The connections for this relay board are:

• + 12V from the RAMPS board heater terminal
• - Ground from the RAMPS board heater terminal
• 5V 5V from the power supply
• C Mains common line
• H Mains hot line
• The other two terminals are for the heater.