Simple RPM meter

thingiverse

Hi, This is a simple mechanical RPM meter I built and perfected over time. It uses a worm gear set with a high transmission ratio (1:50) to accurately count revolutions. All parts are carefully designed with a generous clearance to ensure that all moving components run smoothly and don't interfere with the measurement. The friction couplers for inner and outer diameters function well, but aren't ideal because I aimed for a 100% 3D printed object. HOW TO MEASURE: -Hold the device with its respective coupler against a rotating part -Start a timer (for example 10s or 30s) and count the number of revolutions the worm wheel makes -RPM=(revolutions/time[in s])x50x60s I wouldn't recommend using this tool for more than 3000RPM, as it becomes challenging to track the worm wheel's movement at that point. All parts can be printed with low infill, except the pin. Printing it with 20% or so infill may not provide sufficient strength, so I recommend printing it at 50% infill instead. Platform adhesion (raft) is recommended here as well. For better visibility, you can fill in the gaps of the digits with paint or a similar substance to make them more legible.