Mechanical Counter

thingiverse

I had always been curious about how mechanical counters worked, and it turned out they were surprisingly simple and elegant. Having discovered this, I designed a 3D-printable version based on my findings. Researching online revealed several designs that kept all gearing internal to the number reels, but one in particular stood out for its clarity - shown on the left. This design features three number reels allowing you to count up to 999, using lost motion gear pairs between each reel to transfer motion after a complete revolution of the lower digit reel. This design is based on Matthias Wandel's model, available here: http://woodgears.ca/counter/index.html. I modified some features to make it suitable for 3D printing and simplified the actuator into a straightforward push operation. For complete instructions, visit: http://www.3dprinterclocks.com/page23.html. Print Settings: Printer Brand: Zortrax Printer: Zortrax M200 Rafts: Yes Supports: Yes Resolution: 0.19 mm Infill: Medium Notes: I used ABS for all parts, requiring one of each STL part except the Counter Front/Back (2), Counter reel 2 (2), Lost motion (2), and Lost motion -Drive Pin (2). Additional components needed include: 1 piece Ø 2 mm steel rod, 80 mm long 2 pieces Ø 2 mm steel rod, 100 mm long 2 springs from a retractable pen A Ø2 mm drill for the Mainframe's three holes securing the ends of the Ø2mm shafts A Ø2.1 mm drill to enlarge bores in parts that fit onto those shafts Acetone for solvent bonding some parts together Note: The frame's four components are held together with tabs and slots, requiring a snug but not excessively tight fit. I suggest adjusting the fit with a file until it seems reasonable, allowing easy disassembly once test-fitted.