Specifications

This is a class-# compound lever, with #:# torque ratio on the first (bottom) lever and #:# on the second (top) lever.

It should be able to measure weights from # to # pretty reliably, although I have not been able to optimize it further to support all the way through the most demanding (national) levels. 

To build, 4 * 600 mm sections of 2020 extrusion should cover everything!

Design

The core idea is heavily borrowed from this image I found online:

The main focus in designing was to create a stable and reliable build, as well as to make it as operation-friendly and streamlined as possible for a quick yet precise testing. 

Notes

As I currently understand, the design is not finished! A little bit of additional work is needed before it's ready to build. 

• The essential mechanism of adjustable weight holder (hook) and length measurement tool (integrated together) on the left side of first level is not finished. 
• The cross-section profiles for 2020 extrusion is not fully refined, so fitting the 3D printed adapters with the extrusion can be tricky (depending on the source of extrusion). 

The project is not dead; I will continue improving on it and I plan to build a prototype as well. Meanwhile, definitely feel free to look at or contribute on it!