Switching to RAMPS 1.4

 WORK IN PROGRESS 

Unfortunately there is no (good) customer support for these printers. If you Melzi board brakes, it is hard to get a new one. So I want to show you how to switch to the RAMPS 1.4.

Hardware
You can either buy a full Kit. Or you buy all parts individually, which is mostly cheaper, but the parts arrive at different times. You can still use the old steppers, limit switches, mechanical parts, fans, LCD (if you buy a smart adapter), ....

Stepper Drivers
Update: Got my DRV8825 drivers and i can't recommend them because the stepper drivers are not really compatible with these stepper drivers. Everything works, but there is a loud very high pitch noise. Thats because the motors are low-current stepper motors. For stepper drivers there are more options then just one. The basic ones are the A4988, which only have micro stepping up to 1/16. These were also on the original melzi board. The DRV8825 are capable of 1/32 microstepping, are a bit quieter and provide more current. The top tier stepper drivers are the TMC2100, which have a stealthChop mode so they are the most quiet. They also support 1/256 microstepping. Unfortunately they are quite expensive with over 10€ for one stepper driver. Other version like DSP drivers won't be treated following.

Additionals
The cables of the Tronxy don't match with the required cables for the RAMPS Board. The Ramps uses Dupont connectors and the Tronxy JST. If you don't want to solder your own connectors or crimp them yourself, you can buy full cable kits.

If you want auto bed leveling, you need to buy a sensor as well. I would recommend an inductive sensor, because capacitive are quite temperature and humidity dependent. There are also 5V version available. So you don't even need a voltage divider, octocopler or diode.

Due to the high amount of current needed for the heatbed, I would also recommend you to buy an external mosfet. The connectors at the RAMPS as well as at the Melzi are not suited for such high current.

Replacing the connectors
The original Mainboard uses JST connectors for the thermistors, endstops and stepper motors. The RAMPS board uses Dupont Connectors. You can either buy full kits [Aliexpress], crimped kits to solder the wires together [2pin, 4pin] or buy yourself a crimping kit [1, 2].

Mounting the RAMPS on the Arduino
First stick the Ramps Board onto the Arduino board. There is only one way you can mount it. The power input of the RAMPS board is on the same side as the power input of the Arduino. On cheap kits the connectors don't line up correctly. So you have to bend them a bit to fit.

Installing the jumpers
To get the finest Microstepping on the A4988 or DRV8825 you need to install all 3 Jumpers. See the picture above where to mount the jumpers. It is right below the stepper drivers.

Installing the stepper drivers
It is recommended to look at the pin layout of the stepper driver and the RAMPS. However all A4988 and DRV8825 stepper driver are built the same. So you can use the potentiometer as a reference point, but always double check the pin layout. Be carefull! If you mount the stepper drivers wrong, you will destroy them.

For the A4988 the potentiometer has to be on the opposite side of the fuses (see picture).

For the DRV8825 the potentiometer has to be on the side of the fuses. Just opposite to the A4988!

Connecting the stepper motors
The connector of the stepper motor is just above the stepper drivers for each axis/extruder. They are all labeled on the RAMPS. It does not really matter which way you connect the stepper motors. You won't destroy anything, only the direction is switched. Later you can fix the direction by turning the connector around or defining it in the firmware. So when you loaded your firmware move your axis for some mm in one direction and check that it is moving in the right direction.

Connecting the limit switches
Be carefull when connecting the limit switches. DO NOT connect the + and - pins with your limit switch. You are causing a short and probably destroying your RAMPS/Arduino. See the picture how to connect the limit switches. From left to right there are the pins for the min-X, max-X, min-Y, max-Y, min-Z, max-Z

Connecting the thermistors
Connect the thermistor of the hotend to T0 and the thermistor of the heatbed to T1. The polarity does not matter.

Connecting the heatbed, hotend and part cooling fan
Connect the heatbed to D8. Keep in mind the connectors are at their limit providing that much current to the heatbed. There were many reports on burning connectors, both of the power input of the RAMPS and the connection of the heatbed. So I highly recommend you buying an external mosfet for the heatbed and use (end) terminals for your connections. The parts cooling fan connects to D9. Check the polarity of your connection, because the fan will spin the wrong way if connected wrong.

D10 connects to the hotend. Also use endterminals for the wires!

The fan to cool the coldend needs to be hardwired either to a cable with 12V or you can connect it to your external mosfet input.

Connecting the Display
The last thing you have to do, is to wire the display. For that you will need a Smart adapter. The smart adapter connects to the pins at the end of the RAMPS (opposite side of the power input). This adapter will fit your old screen (2004) or the bigger full graphic LCD (12864). If the screen module has a SD Card reader, make sure you connect the two cables right (EXP1 to EXP1, EXP2 to EXP2). If they are connected wrong you will get a beeping noise (if you have a beeper on the module).

Check all connections, the orientation of the stepper drivers and so on. Then power up the RAMPS board and look for magic smoke. You then have to flash a firmware on your arduino.

Installing Arduino IDE and downloading Marlin
First off you will have to download the Arduino IDE for your operating system. Follow this link: https://www.arduino.cc/en/main/software

Under Download the Arduino IDE chose your operating system and then click on "JUST DOWNLOAD". After you have installed it, you will have to download the Marlin firmware from the github page:

https://github.com/MarlinFirmware/Marlin

Click on the green button Clone or download and then Download ZIP. Unizp the archive anywhere you want.

Configuring the Firmware
Navigate to the extracted Folder and then open the Marlin.ino in Arduino IDE.