Electronic wiring


Electronic Wiring on Ramps 1.4 board

5V or12V probe? Careful choose your schematic

  • 12V probe has 1 Dupont 2 pins connector and 1 red wire left over
    • Red wire left over: +12V
    • Black wire: 0V- Ground
    • Red wire in connector: Signal.





Here is the wiring diagram to use

  • 5V  probe has only 1 Dupont connector with 3 pins.
    • Brown wire (+5V)
    • Blue wire (0V – GND)
    • Black wire (Signal)


  • 5V  probe can be provided with and extender with different colors
    • Red wire (+5V)
    • Black wire (0V – GND)
    • White wire (Signal)

The wiring on the electronic board is similar to the previous version of this probe.

  • The Red wire corresponds to the Brown wire
  • The Black wire corresponds to the Blue Wire
  • The White wire corresponds to the Black wire

Here is the wiring diagram to use



Schematic for 12V proximity sensor

Electronic wiring on Ramps 1.4

On this 2nd schematic, ou will find a schematic closer to what is provided within the kit. With the induction probe, the hot end fan ad the auxiliary blower fan.

On the induction probe, it is provided with 3 wires. 2  (red and black) are connected to a Dupont 2 pin connector, and 1 (red) left alone with a node here, is the power supply of the probe.

Schematic for 5V proximity sensor

Brachement électronique de la carte Ramps 1.4 avec sonde à inductance 5V

This schematic corresponds to the kits provided after 17th October 2016.

This kit is provided with a 5V proximity sensors. The blue wire is the ground wire. The black wire is the signal wire and the brown wire is the +5V powe wire.

If your probe is not provided with a 3pin black connector, please look at the other schematics.

A Y shape wire extender is also provided. It’s directly connected to the 12V power output of the Ramps board and will help you to connect the hot end fan power supply to the +12V. It will also be used to connect the 80mm 12V fan dedicated to cool down your electronics.


You should be able to recognize the other components now. The wire’s color on the stepper motors are only for information, the one provided might have a completely different set of colors. The one on the power terminals are real colors with the red wire corresponding to +12V and the black wire to the ground wire (0V)


Ramps 1.4 Schematic

Ramps 1.4 Schematic

For information purpose here is the official schematic of the Ramps 1.4 board. It is the same you will find on the official reprap wiki  .

This schematic give you more data on all the pin out and also on the optional headers.



A word about the Big green power terminal

Ramps 1.4 power terminalsYou need to understand that the Green power connector on the left of the schematic picture is a Plug connector,

Meaning that the big part with the terminals can be removed from it’s base.

The picture here shows the 2 different parts:

  • On the left the terminal part that can be removed/unplugged
  • On the middle the fixed part, soldered on the ramps board
  • On the right side, the 2 parts attached together.



As visual support here is a picture of the electronic board free from any cables.

If you want compare directly with the previous schematic, you will need to make a 180° rotation as the power terminals are on the right on this picture and on the left on the previous schematic



For the standalone end stop holder (you might not have it, it has been replaced by the one below.)

Let’s start with the cables located on the Y axis, under the heatbed.

Also take 2 « long » U shaped clips and 1 cable tie.


For Integrated end stop, it’s very easy, the picture shows you how the wires are placed.






Pass all the wire inside the chassis.

You should have 2 wires of the end stop and 4  for the stepper motor.

Bring them all together and secure them inside the aluminum profile slot located just behind the stepper motor support


View from inside of the machine, the wires can easily fit inside the aluminum profile slot .

With 2 long plastic clips, secure the wires. Using short clips is not advised because they will raise the chassis of a few millimeters on this side only breaking the overall equilibrium. Use the « long » clips to keep the main part of the clip oriented toward the top of the machine.


(Scalar XL) In the corner of the chassis is located the SSR static relay. Attach the wires with a cable tie with the wires from the heat bed.

This will secure the wires on the same location.





(Scalar XL) Tighten the cable tie.






Take the end stop connector.





At any steps, feel free to go back to the official schematic if you have any doubt about the picture or if it’s not clear.

Place the Y axis end stop connector on it’s place, please read the following to the end before doing anything .

On the picture, the whole set of pins located on the lower left side is dedicated to end stops.

There are 3 rows pins from top to bottom.

The first row is linked to the +5V power (provided from the arduino itself).

The second row is linked to the Ground (+0V)

The last row is linked  directly to the arduino.

Attention: Never connect the top row with the middle row because you will short circuit the +5V generated by the arduino when the end stop will close causing. If for some reason you happen to do this you will cause some irreversible damages to the arduino power supply and the electronics might not work anymore afterward.

Important: All the end stop MUST be connected on the bottom and middle row.

To complete the explanation, you can connect up to 6 end stop  on a 3d printer. for each axis you can have 2 end stops, one for MIN and the other one for MAX position.

The firmware allows to use only MIN end stops and will handle by software the one for MAX position.

So you can reduce the amount of end stops to 3 end stops.

Each columns dedicated to 1 specific end stop.

Each axis is grouped by 2 columns side by side.

Starting from the right of the picture you will get the following :

  1. X MIN
  2. X MAX
  3. Y MIN
  4. Y MAX
  5. Z MIN
  6. Z MAX

You will connect the Y axis MIN end stop at the bottom of the 3rd column from the right..

Now let’s connect the heat bed thermistor connector located under the heat bed.

Locate it’s connector, you will now connect it to the electronic board.




The thermistor dedicated input pins are located just above the one dedicated for end stops.

You will find 6 pins on the same row, with  T0, T1, T2 marking just below.

  1. T0 is for the hot end thermistor.
  2. T1 is for the heat bed thermistor
  3. T2 is an optional thermistor for a possible 2nd hot end.

So, connect the heat bed thermistor on the 3rd and 4th pin from the right, wich should correcpond to  T1

Now take the Y axis stepper motor connector .








The dedicated pins for stepper motors are located below each stepper motor drivers, the small components with the heat sink.

You will find the markings indicating what stepper motor the driver is dedicated to.

On the top row, you have 3 motor drivers side by side. From right to left you have the dedicated axis:

  1. Axe X (marked X)
  2. Axe Y (marked Y)
  3. Axe Z (marked Z)

On the 2nd row you have here on the picture only 1 stepper driver and a free space for a 5th stepper driver.

Those are dedicated to Extruders, the part of the printer that pushes the plastic to the hot end.

From right to left:

  1. Extrudeur 0 (marked E0)
  2. Extrudeur 1 (marked E1)

Now connect the Y axis motor cable on the middle connector of the first row.

Very important: The stepper drivers don’t support to be powered on without any motor attached to them. doing this will definitely damage the component.

Please make sure to have at least 1 stepper motor connected to each stepper drivers mounted on the electronic board!

If you are using only 4 axis (X, Y , Z, and E0) and you happen to have 5 stepper drivers, mount only 4 of them and keep the 5th one in it’s packaging. It can be of some use as spare part if one of the drivers is failing or damaged.

Now let’s look at X axis stepper motor connector





This one is to be connected on the right of the Y Axis motor on the first row.





Now take the X axis end stop






It has to be connected at the bottom of the first Column starting from the right of the end stop dedicated header pins.




Still on the same machine’s side, you should have the Z axis motor connector left.






The Z axis has 2 dedicated pin header’s rows located under the dedicated Z axis stepper motor driver.

You may want to know that 1 single stepper driver can drive 2 stepper motor at once.

Connect this motor on one of the 2 rows.


(Scalar XL) Still on the same side of the machine, you can connect the static relay to the electronic board.

Start by taking a black cable provided with the static relay.




(Scalar XL) Screw it on the terminal connector with the «  » marking and the number « 4 »

(Scalar M) You won’t have any static relay on Scalar M, so take the 2 power wires coming from the heat bed.




(Scalar XL) The other side of the cable is to be connected on the set of power terminals (here blue) with « D8 » marking.

Each terminal connector of this column is identified by a smal marking « + » that identifies the +12V output.

As the wire you have was connected on the « – » pof the static relay, locate the terminal connector with « D8 » marking and connect the wire on the connector below the « + » marking. It should be the 2nd connector starting from the top.

(Scalar M) Take any one the 2 silicon heater power wire and plug it to the same terminal (the silicone heater has no polarity, so there is no ‘+’ and no « -« )


On the static relay side, connect now the 2nd wire (it should be red).




Screw it on the last remaining terminal with the « + » marking and identified by the number « 3« .





(Scalar XL) Connect the other side of the wire on the power terminal blocks, on the very first connector starting from the top, just above the previous wire you connected.

(Scalar M) take the left over heat bed power wire and plug it at in this same terminal.


Scalar XL:

On the XL heat bed, as it’s 220V the heatbed is provided with a Ground wire. It’s the one with Yellow and green color.


The purpose of this wire is to link the metalic chassis of your printer to the ground.

Indeed, if the 220V power wire gets broken for any reason and touches the chassis, your electric panel should crack up.

In order to have a proper connection, you need to connect it to any M6 screw on your chassis.

Here is an example on where you can place it! We choose a Metalic Square as it seems they provide the best location for this purpose.








The picture here is giving you some more information with a set of stickers on the wires. It should help you to figure out better where each wire is located







(Scalar XL) Start by separate the wires coming from the static relay and the other remaining ones..





Place the wires on the slot of the vertical aluminum profile.

You can use 2 « long » clips to help you maintain the wires inside the slots as shown on the picture.



Also add the wires coming from Y axis motor as well as it’s end stop inside the same slot on top of the wires attached to the static relay.

You might have to remove and replace the clips previously attached on the aluminum profile.


Now you can also insert the Z axis motor wire and help you with the already in place clips.




You should have 2 set of wires left coming from the X axis.

Keep in mind that those wires will have to follow the up down movement of the X axis.




Take them in your hand.







Take the 2 sets of wires, 1 with 4 wires and the other one with 2 wires. As they will move at the same time, it’s interesting to keep them together and check that there are enough length for them to go up and down the Z axis.




The best is to have the X axis carriage at the lowest or highest position possible so that you can quickly estimate the amount of wire length needed.

Here our carriage is located at the bottom and we roughly evaluate the length of wire we need for it to move up. mark or keep this length  (here with our hand on top)



You can secure them by inserting them inside the vertical profile slot by letting them exit either toward the top or the opposite.

Secure them with a clips at the level marked by your hand earlier corresponding to the length needed to move all along the Z axis.



You can secure the wires with cable ties.






Now continue on with the set of wires coming from the hot end.

Place them on the middle of the top horizontal aluminum profile.




To make sure you have left enough free cable to allow the hot end to move freely, place the X carriage at one of it’s right or left limits. Here on the lower right corner.

Make sure to have enough free wire for the hot end to move  up and down and also in each corners.



Take 3 clips, 2 long and 1 short.

They will help you to keep all the wires in place in the aluminum profile slots.




Start by securing your wires by placing them inside the top slot of the aluminum profile and use a long clip to keep them in place.





With the second long clip, keep in place the wires up to the electronic display.

You can let free the wires on the side. We will handle them later on.



Take the wires coming from the power supply.

We advise you to twirl the 4 cables together as it allows to easily keep them in place inside the aluminum slots. It also prevent from making any unwanted nodes with other cables later on.



Locate and take the connector from the other Z axis stepper motor that we previously placed inside the vertical aluminum profile. It should exit right next to the power supply if we refer to the previous wiring we did on this part.




Pass it inside the top horizontal aluminum profile and secure it with the last clip you should have.

You can use the already in place clips to secure the remaining of the wire up to the end.




Connect this connector on the pin header dedicated for the Z axis motor, It should be the last one remaining for the Z axis. Here at the top left of the picture.





Take the last stepper connector connected to the extruder motor.

This one must go behind the power supply and follow the sale slot used for the previous Z axis connector.



This should look like on the picture.






Connect it on the last pin header dedicated to stepper motors, below the stepper driver marked with « E0 ».

Here on the second row of stepper drivers on the right.



The cable will go through the same slot as the one used for the last Z axis motor wire.





Now, should remain the power supply power cables to be placed on top of the other stepper motor wires.

The clips should be able to keep all the cables into place.




Connect your wires on the general  green power input connectors.

The whole set has polarity so make sure you connect the + output from the power supply to the + input of the board and the same goes for the Ground (minus) output of the power supply to the minus input of the board « + »-> »+ » and « – » -> « -« .

On this picture the blue cables are the « +12V » output of the power supply (yours should be red) and the brown wires are the Ground output of the power supply (yours should be black).



On the green power terminals a clear marking tells you the polarity of each terminal.

In order to emphasize the polarity of each terminal we added some sticker on the photo .

The ground cables (here in brown, yours in black) are to be connected to the « – » terminals.

The +12v power cables (here in blue, yours in red) should be connected on the other terminals marked with « + » sign.



Once all of them are connected it should look like the picture.








Now take the wires from the hot end fan.





Connect them on the output power terminal (here in blue) on the terminals marked with « D9 » which should be the middle terminals.

The red wire corresponding to the +12V should be connected to the terminal with « + » marking (here the 3rd on starting from the top).

Connect the remaining black wire corresponding to the « – » (ground) just below.


On the recent kits this fan migh already be provided with a 2 pin connector

If your ramps board is provided with a « Y » shape wire extender then use it to connect the fan connector to the +12V of your ramps board.

Take the wires from the hot end.

The fan in front should be On all the time, so it will be connected to the +12V input of the board.



If you have the « Y » shaped wire extender, conserder using it . Use the following step only as an alternative solution to connect the hot end fan to the 12V Power supply.

The red wire (+12V)  is to be connected on the same terminal power inputs marked with « + » along side the wires coming from the power supply.

Here we are using the 2nd green terminal starting from the top.

The black wire for the ground is to be connected to the terminal above with the « – » marking


Regarding the thermistor wire coming from the hot end, it is to be connector on the 2 dedicated pins marked « T0 » at the right of the thermistor dedicated to the heat bed.

Here the screw diver shows where it’s located.





Take the wires of the hot end heater cartridge.

They can be any color (often red or blue depending on the power of the heater cartridge).





The are to be connected on the last power output terminals (here in blue at the very bottom.

The heater cartridge is mainly a resistive element so it has no polarity at all and wires have no + or -, so you can connect them as you want on the last terminals at the bottom.


Now on the inductance probe wire, take the free red wire.





This stand alone wire is to be connected on the « + » marking of the green power input terminals. Take the one you want, here for a better repartition, we propose to connect it to the green terminal at the very bottom.




The 3 pin connector with only 2 out of 3 pins are connected is dedicated to the Z min end stop.

Note: On certain kits the induction prob is provided with a 2 pin dupont connector (black) with 1 red and 1 black wire.

Warning, This connector has a polarity!

The 2 wires must always be connected on the last 2 rows of pin header with the void unconnected pin left alone for the 1 row.

On the version with 2 pin dupont connector, it must also be conector on the 2 last rows.

The green or red wire corresponds to the probe signal, so it must be connected to the signal dedicated line that is the last row.

The black wire is the ground of the probe. It must be connected to the middle row.