• Do not leave the printers unattended. They are fire hazards.
• Some parts of the printer will get hot (the nozzle), try not to burn yourself.

• The printers print with ABS plastic or PLA. These melt at different temperatures, so you will need to make sure

the printer you are using is set up for the type of plastic you are printing.

• The basic process for printing a file is this:

Design shape in modelling program - Export to .stl > Import .stl in open source software - convert to gcode > send to printer.

There are firmware settings on the printer, you should not have to change these. There are also settings in your open source software (print settings) you will want to change thse to suit your print (more in following secions)

• Be awesome. Make awesome things!

Warning the Thing-o-Matic is in need of some servicing. The current known problem is that communication errors result in stops and starts through the printing process causing oozing on your print job. The current theory is that when the heated nozzle was upgraded the power supply ended up with not enough current to supply the needed power for the head and cpu. Has not been tested yet. Possibly using one or two of the hackspace variable supplies could be used to test this.

-The Thing-o-Matic is using the mac computer as a controller. Files are imported from STL files. You then compile them to gcode and print. To print from an SD card an extra step is required where you save a file to an SD card and then insert into the T-O-M. Then from the control panel on the mac you send a command to print from the SD card (Currently fails after 10 or so layers)

See http://www.tantillus.org/Tutorials.html for excellent tutorials.

The mendel max was built by Andrew, with lots of help from Loial. Ask them if you have questions about use.

You can always kill the printer by turning the power supply off.

Install Pronterface (you can use other software, like Repetier Host)

• Open Pronterface
• Change the COM port to the highest number (this is like connecting to an Arduino…because it is an Arduino Mega)
• Hit the 'Connect' button. You should see some code that scrolls up the rightmost panel telling you that the connection was successful.
• Turn the power on (make sure the fan is running and is blowing right onto the Arduino board) <- eventually I will make a case for the fan
• Test your steppers by moving each access a little bit using the manual control panel in Pronterface. Be careful to only move the motors 1 or 10 steps, 100 will likely crash them. If you're worried, you can keep your finger on the power supply switch.

• The printer uses "endstops" to figure out where the print head is before each print. The endstops on the Mendel Max are optical switches clamped to round posts. It is good practice to check them before you start printing because sometimes they rotate out of place. The endstops are little pcbs with black h shapes coming off them. A small metal flag on the printer slides in the legs of the H and triggers an optical switch. To make sure they are aligned, move each axis until the metal flag slides into the h. If the flag crashes, twist the endstop so that it is aligned.
• Calibrate the Z axis. When you home the z axis, the print head should be just above the print bed (about the width of a business card). You can change the distance it sits when it is homed by wiggling the z endstop up and down. If it looks like it's in about the right place, hit the z home button (marked with a little house in the manual control area). The printer will move the z axis until the endstop is triggered. Don't worry if the nozzel crashes into the bed a little bit, that isn't the end of the world, the bed is spring loaded. Wiggle the endstop up or down until you get the print head zeroing at the right height.

• You can always print with the default settings!
• The printer should already be calibrated to print well with whatever material is in it. See "Changing the print Material" below if you want to change the plastic.
• You may want to adjust a few settings for your print. You can find the settings in Settings>Slicing Settings, a window will pop up with several tabs. The settings you will change most often are on the first tab "Print Settings".
• The most common settings to change will be fill density and fill type. This will affect the strength of your print and the time that it takes to print. You can use really low fill densities (especially with the honeycomb fill) I usually use 10-30%.
• You can also change the number of perimeters on your print and top and bottom layers, these are continuous layers on the outside of your part, they also affect strength.
• Try not to screw around with print temperature, speed or extruder settings. You need to match plastic flow rate and temperature to the print speed, so these are tricky to calibrate. If I get the time I will calibrate a set of fast printing parameters and slow print parameters.

All of the 3D printers use open source software to turn .stl files into machine paths.

You will have to find editing software that can export as .stl. These include Solid Works, Google Sketchup (with plugin), Blender, Unity. Etc. If you can't export to .stl right away you can probably find a plugin or use another program to convert the file.

The RepRap Wiki is a good place to go for additional information.

Want something to print? Thingiverse is one of the best sources for free files. Start with something simple to learn how to print.