Update 10/04/2024: Added ‘Outside legs’ version which make it easier to get measurements between the tips.

The aim was to design a pair of callipers that:

1. had no need for hardware (i.e. was fully printable) while keeping amount of components to a minimum, and no supports!
2. could be easily adjusted and hold its measurement,
3. felt nice to use & look good!

Other similar printed tools comprise of flat profiles which wobble & bend far too easily, they also have to be clamped together after the measurement is made, which is a bit of a faff and can result in excessive inaccuracy.

This model solves these problems by allowing you to quickly reference those lager dims. Increased strength is achieved from a monocoque-style leg design that houses all of the working components. The straight legs are 150mm long from the pivot centre, and open up to a maximum of 200mm. Drop a comment if you would like to see a larger version….

I am really pleased at just how well this assembles & works but feel I should caveat this by stating that this is a plastic tool, so should be used as indicative purposes…..and not sub millimetre precision.

I hope you like it!

If you do you may want to check out some of my other DatumCAD designs :)

Assembly:

• Insert the Adjust nuts into the Legs: These snap fit and are deliberately tight to avoid coming out easily (so may require a little force before you get that satisfying ‘click’)
• Connect the Legs together: The legs are identical, so just align the top hole of the legs, then push the Pivot pin in through the hole in both legs from whichever side you prefer and secure in place using one of the Circlips.
• Insert Adjuster Screw: Slide the screw in through the adjuster nut with the plain hole in the middle, then screw in to the threaded nut in the other leg. You should now be able to insert the final circlip onto the adjuster screw. Tip: do so from the bottom with the screw correctly aligned (so the circlip grooves on the plain shoulder of the screw are in the vertical position)
• Enjoy! Your adjustable calipers are now ready to use.