Ultimate Mechanical Caliper

cults3d

This caliper uses helical toothed gears to improve motion continuity and minimize backlash. After several hours of sizing and optimizing the transmission, I came to have a 0.027% error in the transmission ratio, practically infinitesimal considering the small size of the gears and the size of the caliper itself. The mechanism uses two cascaded Geneva mechanisms for counting millimeters (M) and centimeters (C), while for decimals (D) it uses a turntable. The measurements are surprisingly accurate and are almost identical to those of the caliper I use on a daily. Considering the fact that this is a DIY plastic caliper, that's a really cool thing. The measured value is also much more intuitive to read than a traditional (non-digital) caliper. It is a wonderful object that attracts attention and any Engineer or Maker would like to have one on their desk to be admired by friends and customers. A support has also been designed to preserve it and to be able to expose it in a better way. The file can be downloaded at the following link or on my Creations Page. I hope you enjoy building and playing with it. Materials needed - Printed parts - 3x M3x22 Socket Head Screws - 3x Nuts (better if self-locking) For the largest print, a square bed of at least 205x205 mm is required. In addition to all the necessary 3D parts, a practical assembly manual is also available in PDF format. Specs - Maximum measurable length: 130 mm - Maximum resolution: 0.1 mm