UPDATE Haydn Huntley created a new version of the carriage and has been kind enough to publish it. Please check out his carriage at: https://www.youmagine.com/designs/improved-kossel-carriage-for-deltaprintr-or-graber-wheels-and-1515-extrusions For the original carriage design that used cheap nylon rollers:http://www.thingiverse.com/thing:215438Note, his is meant for the Grabber rollers or the Delta Printer rollers. At some point, I'll make a prime line version and repost here. Wing. UPDATE: Temporarily removing the files as I have been notified and confirmed that there is an offset in the bolt mount holes, which will result in a tilt to the carriage when installed. :( Will repost once I have a new file that doesn't have that issue. Description I really liked ElectronicHacks' "Kossel Mini Prime Line Roller Carriage"! The use of the low cost nylon prime line rollers is awesome! However, I found that when I printed them straight up, there was some slack, even after fully tightening. To the point I needed to file away some material to get it to latch onto the HFS3-1515 aluminum extrusions. So after the 2nd one, I remade the model from ElectronicHacks' Sketchup file and removed some material so that the compression arm can come in another 1mm. This is a vertical motion carriage for HFS3-1515 aluminum extrusions like those sold by Misumi. I've included both the modified SketchUp file (forgot the extension) and the exported STL file. For printing, I sliced the STL file in Kisslicer, though any slicer should work fine. The M3 socket tool and allen wrench will come in handy to tighten everything nicely. The M3-10 will be threaded into the side to compress the arm and get the rollers to grab onto the HFS3-1515. I ream out the side hole with a narrow tipped scissor. A file, drill, or other similar tool would work to ream out the hole a bit to avoid splitting the print by forcing the bolt. The unit should grip the HFS3-1515 nicely and still roll freely or with some friction, depending on the level of tightness. The GT2 grip and other bits should be pulled from the original Mini Kossel files and are thus not included here.