Finding the right wire combination

Harrison

I'm making an open source 3D printer as a minor project for my university and I'm having trouble because my motors won't work properly, they either just vibrate in place or don't work at all. I'm using Nema 17 motors with an A4988 stepper driver (<link removed as this looks like spam>) and an Aurdino Mega 2560. I googled how to know the correct Tx and Rx terminals because I thought that was the problem but now when I run the motors separately using the Arduino, power supply and stepper driver it doesn't work at all. Can you tell me how to get my motors running?

droftarts

@Harrison While this forum is for 3D printers, it is focussed on Duet3D controller boards (as distinct from Arduino-based boards) and RepRapFirmware (rather than Arduino firmware such as Marlin). You will probably be better served by posting on the RepRap forums, perhaps in this section: https://reprap.org/forum/list.php?160

However, these are the main thing you should look at:

How is your Arduino connected to the A4988 stepper motor drivers? Usually, an extra board is plugged into the Arduino to make it easy to connect the stepper drivers and motors. For the Mega 2560, it is usually the RAMPS board: https://reprap.org/wiki/RAMPS_1.4 (there are later and earlier versions, but this page has a lot of information on the next points, too).
Check that the phases of the motor are connected to the correct outputs of the stepper driver. See https://reprap.org/wiki/RAMPS_1.4#Motors.
Check the motor current setting, which is done using the trimpot on the driver. See https://reprap.org/wiki/RAMPS_1.4#Drivers and/or https://reprap.org/wiki/StepStick#Adjusting_and_testing_the_current
What firmware is the Arduino running? Make sure the pins definition in the firmware matches the pins you are using to connect the stepper drivers
How are you controlling the motors? If you're using something like Pronterface and sending Gcode, you may need to home the axes, or set their position (usually something like G92 X0 Y0 Z0), before the motors will move.

Hope that helps.

Ian