I was thrilled that I got my little test blocks to print.  So I decided to try and print something a little bigger.  It was just a 3 inch square block about a half inch thick with some beveled edges and screw holes.  I tried to print it many times, but it would get about half way through the build and the extruder would jam up. I tried and tried and tried, but to no avail. I figured there might be something wrong with my file, so I decided to go with a "known good" source file.  I broke down and printed the gear set that Airwolf3d suggested I print in the first place.

Great news, the gear set printed, without a hitch!  Bad news, I must be doing something wrong with my own design files.  Back to the books I went and I learned lots of things.  Different plastics melt at different temperatures.  You can define this when you "slice" the file before printing it.  There are about a hundred other parameters you can define when you slice the file.

So what is slicing?  That is the process of translating a three dimensional CAD file (usually in .stl format) into commands that the printer controller can understand.  The file that the printer controller reads is called a gcode.

Airwolf3d recommended I use an open source slicer program called Slic3r.  Looking at all of the things you can control there was a bit overwhelming, but I eventually learned where to fine and set the basic parameters such as temperature, speed, and slice thickness.  Airwolf3d also provided me with some prebuilt slicer configuration files that worked with my 5.5 printer.  These configurations were the basis of my work, and I just tweaked them here and there as I learned how to use the features.

It was two weeks of trial and error, mostly error, before I successfully printed anything.  This first functional part was a mirror hanger.  This is a 1.5" X 1.5" X 0.0625" square with a rounded top to act as a hinge.  It was a very simple part, but the hard earned knowledge I acquired building it will take me a very long way.

So I have this idea that I'm trying to patent and bring to market.  It is a universal adapter that allows me to attach just about any smart phone to a rifle scope and record, through the scope, what I'm hunting.  I've built several working models in my garage out of scraps of PVC pipe, MDF, craft mirrors, sheet metal, paperclips, screws and Elmer's glue.  Resulting videos can be seen at www.crosshaircam.com
As functional as these prototypes are, they still look like they were kluged together with scrap material in my garage.  Mass producing these was out of the question.  There is just too much work involved in fabricating the parts, and more importantly, aligning everything so that the image was properly centered in the camera.  And marketing these contraptions was out of the question.  People could understand and appreciate concept, but wouldn't want the clumsy looking thing attached to their hunting rifle.  I needed something more professional looking and 3D printing looked to be the most affordable option I had.

After a few weeks of research, I decided to buy an Airwolf3d v5.5 printer.  I chose this one for the following features:

• It could be purchased fully assembled
• Fast print speed (100mm/sec)
  
• Low cost per part
  

• Printed a variety of material

The day it arrived, I unpacked it according to the instruction manual.  I also had to perform a bed leveling procedure.  This took me about 4 hours, because I was being extremely careful, reading and re-reading the instructions at each step.  I really didn't want to trash a $1600 machine the first time I flipped the switch.  I successfully printed a preconfigured circular test pattern that came with the printer.  It was much easier than I expected.  It was too late for me to do any more with it, so I let it sit until the next day before attempting to print anything else.

Instructions recommended printing a pre-packaged file that included a set of gears for the printer.  Sorry, I was no longer that concerned with trashing a $1600 machine, I wanted to print something of my own.  So I opened Google Sketchup, which I had begun learning to use while I was waiting for my printer to arrive, and drew a set of interlocking blocks shown here.

It is purely by luck that these things printed at all.  I hadn't "sliced" the file, I simply opened it in the printer software and hit print.  Since these were very small parts, 1" X 2" X 1/4", Pre-heating the extruder made it hot enough to melt the plastic for the entire print.

It took me a week and a half to figure out why I couldn't print anything bigger.