With the hardware side of things in the good hands of Mark, I thought it might be good to let you all in on the software end. Since I know many in the audience here will be new to 3D printing I will start off slow with definitions and basics. I also like feedback so please give it. I just ask you be constructive about it.

To start we need to define our system. The H-Bot is an extruder style system, also called Fused Deposition Modeling (FDM). In other words it pushes out hot plastic in many layers to build up the desired object and is similar to the RepRap in philosphy. There are stepper motors that control the position of where the plastic gets extruded as well as stepper motors controlling how much plastic gets extruded. Additionally the HBot has sensors that measure things like Heat, voltages, endstops, etc in order for things to work properly.

In the HBot all these things, as well as input from a PC or an SD card, are directed and read by a microcontroller (An Arduino Mega 2560 with the ramps V1.4 shield). The microcontroller has a piece of software that is called the Firmware. If you have dug a bit into the current 3D space you may have seen names like Sprinter and Marlin. These names are referring to different versions of Firmware. You can think of the firmware for the microcontroller like the OS to a PC. Sprinter and Marlin is analogous to XP and Windows 7.

Now the firmware needs to get its instructions from somewhere. This can come from a variety of sources but the primary ones are SD cards on the printer itself or sent through a USB port from a PC. In the case of the SD card, it is the responsibility of the firmware to find and read the correct file to supply itself with instructions. In the case of the PC these instructions are sent to the microcontroller over the USB from a control program on the PC. Familiar names here are ReplicatorG, PrintRun, and Pleseant3D. Frequently these programs will also include ways to control other functions of the printer like, homing, temperature and speed adjustments.

As it happens the instructions that get sent to the microcontroller are frequently in the form of GCodes (This need not always be true but in our case and many others it is with slight modifications) While the control software is responsible for sending the proper GCodes to the firmware to control the machine they do not strictly generate the GCode itself. That is the responsibility of another piece of software called a "slicer" in this world. While the slicer is a seperate piece of software logically it is frequently integrated into the control software to varying degrees of transparency. The most common open source slicer is Skeinforge, while a commercial one is Netfabb. Slic3r and SFact are also popular slicers.

The Slicer itself needs to feed with something and that something is the model of the object almost always in STL format. This format can be generated from any number of cad software (Sketchup, Blender, Rhino, Solidworks) or even 3D scanning software (Meshlab, ReconstructMe).

So thats the basic layout of how software plays a role and integrates into the workflow with a 3D printer. I will add additional articles going more into depth for each one these in the near future and why we made the choices we did (at least up to that point in time). Things are in high flux in the 3D printing community currently and as such we will adapt and change to keep apace the best we can.

 

Great write-up, Nick! Looking forward for the other upcoming info.