Self-Locking Sewing Edge/Hem Ruler

I loved @jtorregrosa's Sewing Edge Ruler design but wanted a version that securely locked itself in place. This version is inspired by his design but modeled from scratch by me. The main differences are:

- Self-Locking Design - This version includes clamps that lock the slider in place. Pushing in on the outside of the clamp arms releases the tension and allows you to slide it to the desired measurement. - Multiple Measurement Units - This version features centimeter/half-centimeter markings on one side and inch/half-inch/quarter-inch markings on the other. - Two Sizes - Ruler.stl includes measurement markings up to 20cm/8in (though the slider will not actually lock to those lengths) and can be printed on a MK3. - The longest length that can be effectively measured with the slider is ~16cm/6.25in. - Ruler Mini.stl includes measurement markings up to 16.5cm/6.5in and can be printed on a Prusa Mini. - The longest length that can be effectively measured with the slider is ~12cm/4.75in The tolerances are intentionally a little tight to keep the slider secured even if the plastic bends a bit under the repeated stress, but obviously that's based on the output of my own printer. Let me know if it's too much/too little and I can try to include tweaked versions.

The pictured versions were all printed at 0.2mm layer height with Overture PLA.

Note : Though they are similar, the components of this version are not interchangeable with @jtorregrosa's design as the dimensions are slightly different.

Changelog :

- 2024-09-04 - Added v2 locking slider with tweaked tolerances and narrower arms for easier use.