This is a simple J-Head/groove mount for a Rostock platform and pneumatic fittings. The uploaded STLs are for 5 mm pneumatic fittings but this can be customized in Customizer. Many of the settings available in Customizer don't need to be (and probably shouldn't be) changed, just update "Pneumatic Fitting Drill Diameter" and "Pneumatic Fitting Thread Length" to the appropriate size. I had initially used and uploaded a variation of mattschoenholz's J-Head mount, however I found that it was unnecessarily complicated, made wiring difficult, and reduced the overall printable height. 25-Feb-2014 Update Support has been improved. Old support has been replaced with a spiral support that I've found much easier and cleaner to remove. Also in this update added support for double J-Heads. While I have not tried this configuration, it should work. Please let me know if you try it. 15-May-2014 Update I have recently been using this mount with a Hexagon Hot End with no issues. I've updated the title/description to be more widely applicable. No changes to the model.The uploaded STLs are for a 0.35 mm layer width (nozzle size) and a 0.20 mm layer height; if you are printing with different settings then use Customizer (or modify the OpenSCAD file) to adjust accordingly. The layer width and height are only used for generating the support. Print both parts. I print the groove mount plate part with 100% infill, and the pneumatic fitting holder part with 20% infill and I have not had any problems. You will need to remove the spiral support from the bottom of the pneumatic fitting holder part. To do this I use some needle nose pliers and grab the center of the spiral and twist and it comes right out. You will also need to drill or cut out the hole for the pneumatic fitting. For smaller diameter holes use a drill bit of similar size, otherwise cut it out with a knife.