This is a 2:1 proportional caliper. If you set the larger end to a distance, flipping it over will yield exactly half that distance between the other two points.
That's it!
I was drawing Voronoi diagrams and I didn't want to mess with a bunch of compass constructions to find the midpoint of so many lines.
You could also use it for taking measurements when drawing from life, but you're stuck with the 2:1 proportion.
If you want to change the proportion you need to change the location of the pivot:
A 1:1 ratio would place the pivot at 1/(1+1) the length of the calipers, or halfway (duh).
A 1:3 ratio would have the pivot at 1/(1+3) the length of the calipers: 1/4 of the length.
As I've said these are at a 2:1 (or 1:2) ratio which is why the pivot is at 1/(1+2) or 1/3 of the length.
This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/0sTZBgFihRC
| 21_dividing_caliper.stl | 16.0KB |
