NOTE: This Thing is probably not water-tight. It prints out perfectly in ABS on my MakerBot Replicator 2X. If you've spent much time leveling your printer's build plate (and you should, as it is probably the most important part of a successful build) you know how tedious and aggravating it can be. Having a dial indicator and a jig of this type, which sits on the 8mm rails of the gantry is a real time saver, and more accurate than using a piece of paper. You will need to move the gantry (and the jig) around by hand, after bringing the build plate up high enough to engage the tip of the indicator. Do not use this with the built-in leveling routine of the printer. Zero the indicator, and adjust the three leveling screws below the build plate as needed to get the indicator to read 0 in all positions. If the build plate is a bit warped, you should still be able to 0 it in four corners. For this Thing I took measurements of my new MakerBot Replicator 2X, from the rails of the gantry system (both their distance apart and their diameter), and the allowance needed for the X-axis belt. Of course trial and error needed to be made to allow for shrinkage of the ABS filament during building. After two builds I felt I had the measurements I needed and the third build fit very well. For the indicator I chose the Anytime Tools Digital Electronic Indicator (available from Amazon, p/n AT203188). The hole for the indicator is a standard 9.47mm (3/8") dia. I found this a press fit, but it could be reamed as well. Holes are provided for rare earth magnets (Radio Shack p/n 64-1895). These are 1.51mm thick, and a nice press fit that should put them just above the rails when in use. They hold the jig very well. Start installing them by placing them by hand as level as possible above the holes. Drive home with a blunt plastic object until level below the holes. I've included thru-holes to allow a 1/16" drill bit to be used to push the magnets out again if you have problems. A pilot hole is included in one side in case you want to drill and tap for a set screw to hold your indicator in place. As for the settings, use ABS (I used Octave 1.75mm ABS), Standard setting (.20mm layer height), with a 10% infill, 3 shells, 230C extruder temp, and build plate at 115C, with a raft. Lay the jig on its back on the build plate so that no support is needed