UPDATE: Improved markings for higher precision, reduced print time to 1h 39m, added optional detent spring for more stability
 

Sometimes 15 cm just aren’t enough 😄

That’s why I designed this extra long caliper, an extended 3D printed measuring tool for large objects.

This extended caliper fits on almost any standard 3D printer bed (250 × 65 mm) and allows precise measurements up to 450 mm, far beyond what standard calipers can handle.
 

The 3D printed caliper consists of two sliding parts that simply fit into each other, making it easy to print, assemble, and use.
Optionally, you can add a detent spring for more stability.

Perfect for 3D printing, woodworking, DIY projects, and large-format measurements.
 

Usage note:
For lengths greater than 22 cm, use the upper-left marking; for lengths below 22 cm, use the lower-right marking. 

The mentioned markings refer to the inner measuring edges. When measuring with the outer edges, add 30 mm to the result.
 

Assembly note:
Simply slide the two parts into each other. Optionally add the detent spring. If the fit is too tight, use some oil on the sliding surfaces, especially with the spring.
 

After assembly, check whether the zero position aligns with the markings. If not, lightly sand it down until it fits

Print note:
The left part should be printed with the ruler markings facing the build plate. The orientation is already correct in the included printing profile.
The spring should be printed with PETG, as it is more flexible. There is an extra printing profile for it.

Prototyping: