LMR is a great place to work together, learn and build. When you put cool new tools and tech in the hands of the community here, we can make awesome new things! When I first started wanting to build a 3D printer in 2009, there honestly wasn't much documentation out there to learn from like today, and lots of my questions were left to the Great Google. Here is an attempt to at least collect some info for those starting on the 3D printing path...
The workflow of idea to object goes first from design in software, to processing the file into Gcode (files used for production), and using a host to control and send the gcode to the printer...
Google Sketchup - Easy to use and get started drawing, plus lots of examples and tutorials
HeeksCAD- Open source and cross platform, easy to use liek Sketchup, but kinda crashy.
OpenSCAD - If you prefer code and programming, this is the tool for you.
TinkerCAD- Available via web browser, great for teaching kids. We use it at our local Raising Makers program!
AutoDesk 123D- Also nice as a teaching tool, comes with other apps like 123D Make (export for fabrication for cardboard) and Catch (3d scanning)
Pen and Paper - Never underestimate the power of the almighty pen! It can't export to digital file format, but sure makes for a fun afternoon and digital design is way easier once you have *something* to look at.
This list is by no means comprehensive, there are also lots of great paid design tools out there, so choose the one that works best for you!
With any of the above, you can export your file as an .stl and move on to the next step...
Gcode is the language that your printer uses to make its movements that comprise your objects. You'll need a processor like Skeinforge, SFACT (simplified Skeinforge) or Slic3r to process your .stl's and load to your printer host. Again, they all have their quirks, but basically Skeinforge gives you the most parameters to manually set, and can produce beautiful objects, or piles of plastic to cry over. SFACT simplifies those parameters, and Slic3r pretty much automates all of them, giving good prints right off the bat, but also contains some bugs that are evident in tricky prints. Most printer hosts can integrate these into their operation, which is really nice and convenient. I've included some Skeinforge settings in the attachments (PLA.zip) that we have shared at our local makerspace. You might find them helpful, and they produce some pretty nice prints.
In case you don't think Skeinforge is for you, this is the main portion of settings that are contained and can be entered in your favorite gcode processor:
Layer height: 0.2mm
Feed rate: 50mm/s
Flow rate: 50
Perimeter feed rate: 20mm/s
Perimeter flow rate: 20
First layer feed/flow rate: 70% of normal feed/flow rate
Edge width over height: 2.05
Fill width over height: 1.85
Minimum layer time: 40s
Firmware is what you load onto the set of electronics that control the motors, heaters, blinky lights, and other features of your printer. It takes the data that your computer is sending, and converts it into the actual movements your printer makes. Again, there are lots of versions of firmware, and trying to stay up to date is a pain. Currently, versions like Sprinter and Marlin are the standard and work with most electronics kits. With custom electronics, you might want to try alternatives like Repetier as they can provide some cool functionality other versions do not present.
This is the GUI that you load gcode for prints, manually control the movement of your printer, and monitor it while printing. The Printrun suite is most popular at this stage, it is quick to get dependencies installed and easy to use. Repetier also looks nice and provides its own set of features to make using it easy.
As with all achievements we strive for, challenges constantly arise. Sometimes it seems like the building and tweaking will never stop. Well why should it? We are scientists, hackers and inventors! Prints fail, quality improves, kids accidentally kick your printer at the library (true story) and a new cool design is going to come out tomorrow. If you're in it for the journey, by all means, march forward.
Having people you can call on in troubleshooting is very important, but community is something that LMR has in spades. Its a privilege to share in someone's trial and error, learning, and experimentation. Got questions? Then ask ask ask away! Reprap has a great IRC channel as well, where many enthusiasts hang out and can help, much like our shout box here.
Choosing a Printer
Choosing what printer is right for you is very important. Kits are available from many proprietors, and you can even find a friend to help you make a set. Lots of new designs come out all the time, and when choosing what printer I'd like to make next, I look for key values like simplicity of the build, stability and compatibility with existing pieces that work, and improvements that keep me excited about innovating the technology.
Thanks for reading, and I hope you find this helpful. Take what is written here with a grain of salt, and look to serve your preferences. If you don't ming, let me know if I'm missing information that you feel is important, and I'll update as necessary.