Aluminum tubing marking templates

thingiverse

While building robots for First Robotics Competition (FRC), we frequently rely on a lot of 1" and 1"x2" aluminum tubing, drilling numerous holes in the process. Measuring and marking multiple 1/4" holes at precisely 1/2" on center, right along the center line of a 1" tube takes an inordinate amount of time to execute accurately (utilizing calipers and edge markers). When students use tape measures or wooden rulers, results are far from precise enough. A water-jet or CNC machine would be fantastic, but this little helper is more reasonably priced. Enter the edge-guides. Easy to configure for various size stock, I've included several of the most commonly used ones. The 2in edge marker.stl and 4in edge marker.stl have the center line positioned exactly 1/2" from the edge guide and tic-marks start just 1/8" from the side, spaced at 1/8" intervals. The 2in cross marker.stl makes tic-marks across a 2" tube, starting at 1/8" from the edge. It's 1/2" wide, with the center line located precisely 1/4" from the end, making it also suitable for marking off mounting holes at the end of the stock. I've added a 3/4" wide guide for some flat stock we're currently using. Additionally, I've included the gcode for all four of these to be printed together. These print settings worked exceptionally well with PLA. Update: Modified scad for a multi_edge_guide, which allows passing the locations for one or more sets of tic marks, rather than just one midway through the width. This enables me to create a single guide for 2" tubing with two sets of marks, one at 0.5" and another at 1.5" from the edge guide, both based on the same reference edge. I've also included the .stl file for this new guide. Print Settings: Printer: Monoprice i3 Rafts: No Supports: No Resolution: 0.1mm Infill: 20% Notes: I printed all these in PLA with a 0.1mm layer height. While slowing down the print speed might have provided even greater precision, they've worked fine at Cura's default "normal" print speeds.