UPDATE 2024-09-09: New version of the source code,

1. now can be configured either in metric (cm) or imperial (inches)
2. labels on both axes
3. rounding on corners
4. can add a lip on either edge
5. radial marks are more configurable
6. gauge states the units - in. or cm

ORIGINAL:
When I need to draw a rounded corner on some piece of wood I usually go looking for something round like a roll of tape. Or a compass.

So I made this quarter-circle arc drawing template. The OpenSCAD source is set up to use the customizer (not likely to work in Thingiverse's ancient version of it) but you can just edit the source code directly. An STL file is included for a reasonable size template.

You can edit

• the native units (inches or centimeters_
• the smallest arc radius (in inches or cm)
• the largest arc radius (in inches or cm)
• the step value between arcs (in inches or cm)
• the gap size of the pencil slot, one for the top and one for the bottom
• whether to put radial lines on the template (no reason to turn this off)
• the degrees at which to put the radial lines
• the thickness of the template
• font for the notation
• a couple of padding parameters

The precise position to draw the arc is in the center of the slot. There's a photo here that shows that it's very accurate, though the photo suffers from some parallax issues that make it look to be slightly off.

This is printed upside down. You can ignore PrusaSlicer's warning about stability. You can print the bottom few layers inn a different color so that the recessed text and lines stand out better.

Creality

Ender 3 Pro

No

No

0.16

50%

These are just the values I used. They don't really matter