I've recently started with a Printrbot Simple Metal kit. Truth is, I have no real use for it other than I've been fascinated with the whole 3D printing thing for years and just had to scratch that itch. The whole thing cost me $622 shipped to my door with a full roll of PLA. I plan to upgrade the unit to a heated bed so that I can print using ABS. I'll also add the LCD admin panel for stand alone printing. I have printed many cubes for checking and adjusting the calibration of the unit as well as novelties such as a few treefrogs, a Mario and also an angel figurine. The useful prints, thus far, have been for the printer itself. The Simple Metal really needs a spool holder. When first running the machine I enlisted the help of Tinkertoys, because Legos are evil and get all the love on the internet. Tinkertoys and Erector sets are where it's at! The current spool holder was found on thingiverse and uses printed parts plus PVC pipe much in the same vein as Tinkertoys. Because the unit is made from mostly powder coated aluminum it seems fairly stable with no discernible slop. This was the major selling point for me. The fit of all the parts is excellent and the instructions found online, although brief, are more than enough to successfully assemble the printer. There are many forums and many resources online that helped me calibrate the unit.
There's the review, now on to the question of "What is worthwhile to print?". I heard this explained once in a Computer Documentary. As I recall the gentleman speaking was at one time the president of the Homebrew Computer Club. This was in the day when Woz and all the early pioneers were sharing circuits and ideas to realize the dream of owning their own computers. He said, when asked "What was it for?", a few people created programs to balance a checkbook or to keep recipes. He called this 'Function Guilt'. He went on to explain that no one asks why someone erects a train set in his attic stating "I play with it, it makes me happy.". It's the same thing with my 3D printer.
Now as for a more practical application, I'll use our own RandyT from GGG as an example. He owns a 3D printer and I would imagine uses it for some prototype work. In a recent thread he made some gears for a broken Star Wars Yoke. You can read about it here, just ignore the haters and look to the content.
http://forum.arcadecontrols.com/index.php/topic,136593.msg1413454.html#msg1413454If you needed to make only a few of something, or a prototype, I would think these little machines are the way to go. As for me, I play with it, it's fun. I'll send some pics along in a later post.
Regards,
Scam
Edited to add pics of the Old and New Spool Holders