[elliotf]

Sure, there are a few reasons:

1) The first one was horrible, so I eventually ended up scrapping it and using it for parts.

2) The second one (Printrbot+) is/was fine, but is _extremely_ awkward to move around: The printer, power supply, and print spool are three separate pieces, and it had some serious design flaws, so I build my third, which I can carry the entire assembly with one hand. I used the second to print parts for the third, then (once I had the third working correctly) I rebuilt the Printrbot+ addressing some of its flaws.

3) It's fun to design and make 3d printers.

I might sell the Printrbot but I'm not sure what kind of market there is for used hobbyist 3d printers.

I'll probably build more, too. It's my first adult hobby that is unrelated to my work, so it's a nice break. A corexy printer is next up (http://corexy.com/)