How to Connect the Motor and Position-Sensing Wiring to the Electronics on Your RepRap 3D Printer
As an aid to wiring all aspects of the RAMPS control board on your RepRap 3D printer, you can see a very clear diagram produced by Neil Underwood on the RepRap Wiki:
At this stage, you have various components — all with connections — fitted to our 3D printer. You connect these parts to our RAMPS control board, using the steps that follow:
Connect up the two Z-axis motors that drive the vertical axis.
Both motors connect to the same stepper-driver Z connection on the RAMPS board. You'll see two sets of four pins each, near the Z-axis stepper driver. All the motor connections are labeled 2B, 2A, 1A and 1B, depending on the type of stepper motor you have and how it's wired internally.
You may need to fit the four-pin connection one way around or the other. Motors are most commonly wired with red, blue, green, and black wires.
If you reverse the four-way connector, you reverse the motor direction, but you can also do this reverse in software. So, if you have connectors that have locking tabs, don't worry; you can reverse the direction later.
Connect up the X and Y motors to the four-way motor connectors marked on the RAMPS board.
Connect the heated-bed to the thermistor (temperature) sensor, and to the heating element (usually fitted with thick wires).
Connect the two-pin thermistor wires to the T1 connection on the RAMPS board. The wires can go in either orientation.
Connect the power connections of the heated-bed into the D08 connections of the RAMPS board. Be sure to use ferrules here.
Fit the three end-stops to the RAMPS board.
These are clearly labeled on the RAMPS board; they have six connections — marked MIN and MAX — for connecting both home sensors and full-travel sensors.
Almost all 3D printers do not fit the MAX end-stop connections physically. That's because you can state in the firmware where the maximum travel of a machine is.
Only the MIN end-stops have been fitted in these steps. These must be connected in the correct orientation, so check your specific build manual for these connections. It's most likely that you have a red wire and a white wire: red is +5V and white is the signal connection.
Tidy up any wiring with tie-wraps as required.
Prepare to install the stepper-motor driver modules to the RAMPS board.
Carefully check to ensure that the stepper driver is correctly oriented. The stepper modules fit into rows of pin headers running down the RAMPS printed circuit board.
Make extra sure to line up Pin 1 on each module with Pin 1 on the RAMPS connector.