DevCnc Foam by the devCad Team

The Arduino Mega + Ramps is a well known controller in the 3D printers world.
It includes all what is required to build in a simple way a powerfull foam cutting controller:

• 5 stepper drivers. Actually we just will use 4 of them, but we are already working to a Foam Cutting cnc with an added rotary axis...
• 6 limit switches input. We will use 4 of them, one for each axis
• a PWM 12v - 11A power output. We can use it to drive the hot wire or an external high power unit, both in On/Off mode, or in PWM mode (controlling in this way the hot wire temperature)
• very simple wiring. Ramps fits directly on the Arduino Mega board, and the stepper motor output are already ready to use with a standard 4 pin dupont connector, the most used by stepper motors.

So, why this solution isn't actually used in the Foam cutting world?
The answer is in the lacking of a Firmware for Arduino, able to manage the 4 independent linear axes in the way required by cnc foam cutting.
That's why the devCad Team developed a totally new Firmware, optimized for Arduino Mega + Ramps.
This firmware will be stored inside Arduino Mega directly on devCnc Foam startup, when you select it as the actual controller.
So you don't need to begin an Arduino expert, but just:

• apply the right wiring (no soldering is requested)
• calibrate the stepper drivers (they usually are already set to a good enough value, but checking it is recommended)
• plug in the Arduino Usb port
• select Arduino Mega + Ramps in the "Controller type and output pins" page of the "Settings dialog"

At this point all the firmare setup will be performed by devCnc Foam, you must only set the right Steps per MM values of your Cnc, see the "Motors" page of the "Settings dialog".

You can find here the Step by Step guide to setup your Arduino Mega + Ramps controller:

• Gently connect the Ramps shield int o the Arduino Mega. Check carefully all the pins are straight, or you can have problems in this operation
  
• Set the right micro step value for each driver stepper , inserting the supplied jumpers in the pins. You can find the table of the pins to jumper in the documentation of the stepper drivers you use, search it in the web.
  Here below you can see where the microsteps pins are located for each axis. The rotary axes is for future development...
  A good starting value can be 1/8. You can select an higher value to have max movements smoothness, a lower value to have higher max speed.
  
• Insert the stepper drivers. Pay attenction to check to insert them rotated in the right way. Don't take as a reference the stepper image, but the pins. The Ground and Dir pin must be located at the right side, watching the supplied image. See the below picture as a reference, again the rotary axes is for future development...
  

• Connect the power cables and the optional Hot wire output. The Ramps shield have 2 different power inputs, both of them at 12 volts:

  • The main power inputs, located in the low side of the picture. This is mandatory, a 12 v and 5 A power source is required here.

  • A secondary power input, required if you are going to use the optional Hot Wire control. If you don't use the optional Hot Wire control you can ignore it.
    If you are going to direct drive the Hot Wire, you can have max 11 Ampere here. If you use a long and thin hot wire and you need more volts, you can use an external DC-DC power step up unit.
    If you are going to use an external On/Off switch driven by Ramps or you are getting a low current, you can also jumper this secondary power input abd use the same power wires of the main
    
    

• Calibrate the stepper drivers. To calibrate the steppers drivers you must use the procedure suggested by the stepper driver manual, find it in the web. This can slightly change for each stepper driver model.
  We suggest not to set the higher possible current. If your machine carriages run smooth (as desired!), a medium current value is better.
  
• Connect the stepper motors. See the below picture.
  
• Connect the optional EndStop/Limit switches.
  This connections don't requires an external pull up resistor, as it's already supplied internally. Just connect one or two switches for each axis, read also "Hard Limits"
  
  
• Select the Arduino Mega + Ramps option in the "Controller type and output pins" page of the "Settings wizard", insert the proper values in the "Motors" page, and setup the optional "Hard Limits" and "Hot wire management".
  When closing the "Settings wizard" devCnc Foam will check and eventually upload the right firmware you are ready to go!