Just got my Printrbot Simple Metal the other day. After fiddling with it and getting it adjusted out, getting some great print output. One thing I wished I had purchased with it was a spool holder. Was planning on making one out of PVC pipes until I came across this wonderful project. Started printing out the base for the Printrbot not realizing how it was used. After an hour of printing, it dawned on me. It goes on the top of the z-axis bars. Even better. But then started thinking. How does that affect the stability of the printer moving the center of gravity so much higher? Anyone with a Printrbot who is using this have any comments on the stability of the unit with a 1kg spool up top?
Oh, and I really could have used this spool holder while I was printing it. :)