These adjustable jaws were designed specifically for the Harbor Freight 40" rule, but may work with other similar rulers. When attaching the fixed end, make sure it is fully seated and the edge lines up with the 20mm mark. Fusion 360 and STEP files added 3/1/23. The F360 file includes user parameters to adjust the model to fit ANY size ruler.
The printed knobs and jaws have modeled 3mm internal threads which you may need to chase with a tap. Use 3mm x 10mm socket head cap screws and screw the knob on fully. It should be tight enough as is, but if it becomes loose, a dab of super glue should hold it.
DO NOT tighten the screws too tightly on the ruler as it could damage the edge and make the moveable jaw hard to adjust.
I have also created a Marking Gauge for the HF 40" rule here: https://www.thingiverse.com/thing:6583550
| Fixed_End.stl | 264.3KB | |
| Knob.stl | 414.1KB | |
| Movable_End.stl | 307.7KB | |
| Ruler_Caliper_v13.f3d | 851.4KB | |
| Ruler_Caliper_v13.step | 2.3MB |
