I just finished upgrading 3 of my Wanhao Di3’s. One is stock, but has had the Z braces added, and a new parts cooling shroud added. The second one is running a C3D mini board (Smoothieware) with the Z baraces, and the third one is running a C3D mini board with a bowden setup with an E3D V6 clone head.and Z braces.
First thing I noticed is the Smoothieware based machines keep the temps dead on for the heated bed and hot end. The stock Melzi machine has temperature fluctuations of up to +/- 3 to 4%. The Z braces have made a big difference in print quality.
Next upgrade will be inductive sensors on the Smoothieware machines for bed leveling. But before I do that I need to finish wiring up my custom built 300X300X400 printer that was made with Openbuilds rails and wheels, using custom laser cut carriage plates (You can take a look at it at https://openbuilds.com/builds/voxel-evolution.7026/)
My printrbot Simple Pro is waiting on a replacement hot end, and I have built one of two Tronxy X1 printers (A few part upgrades on it to make it usable). My printer farm is starting to crowd me out of space, I think I need to make some multilevel shelving to put everythingh on, or move my 4 laser cutters around to make some more room. (I already had to move my CNC router to another part of the house, and I have a smaller CNC mill that I am building right now that will need to find a home.)
I think I have a machine addiction, is there a 12 step group for people like me? 

