Lathe QCTP DTI (Quick Change Toolpost Dial Test Indicator) Fixture

thingiverse

This is a QCTP DTI (Quick Change Toolpost Dial Test Indicator) holder for an Aloris, or Aloris compatible, fixture / toolholder. It holds a standard round indicator with a 1/4" x 1" lug on the back. The photo is of a CA toolholder, but I've provided files for AXA, BXA, CXA, and CA QCTP holders. Specifications for all of the dovetails have an angle of 60 degrees and is as follows: AXA: Dovetail Depth - 0.385 Dovetail Width Max - 1.687 BXA: Dovetail Depth - 0.417 Dovetail Width Max - 1.761 CXA: Dovetail Depth - 0.555 Dovetail Width Max - 2.201 CA: Dovetail Depth - 0.49 Dovetail Width Max - 2.66 I've added a small fraction to the dovetail max width, as I found without it that the fit was a little too tight. I've included the Inventor files as well in case you want to modify the model for your QCTP configuration. Note: Ignore the two tone print... I almost ran out of filament (didn't pay attention to how much was left on the spool prior to starting the print) so swapped filament mid-print to another spool which was a different color. Instructions Print the part for your size QCTP For the height setting it is sized for a 1/4x20 screw to self tap into the plastic. use a washer to set the height onto the top of the QCTP. I have found that the easiest method to find the center is to mount a sharp dead or live center into the tailstock. You can also scratch a piece of stock with an already center set cutter. Many lathes will also have a line on the tailstock for setting center (if yours doesn't, set the height and make a scribed line on the tailstock with a cutter, these lines are invaluable for quickly setting toolheight) which you can then mark more clearly with some RED nailpolish or similar high contrast enamel. You can mount the DTI into the fixture with another bolt, or just jam fit the DTI into the fixture, or fix it in place temporarily by inserting a screwdriver through the fixture and the hole in the DTI lug. You'll figure out what works best for you. This has proven invaluable for quickly centering stock in a 4 jaw chuck. No more hunting around for a magnetic base and fiddling about with it trying to get it centered. Just drop it onto the QCTP, center the work, and back to making parts! :)