This is WIP.
Concept for a mechanical scale for measuring the mass of small items. Inspired by rolling postal scales. Can measure weight dynamically.
This was made primarily as a physics demonstration gadget, meant to be remixed and tinkered with. It is NOT precise and should not be used for situations that require a real scale. Basically, it's designed to be a toy. I am not accountable for it's misuse.

Hello there! Sorry but I need these warnings just in case. This is a goofy project I started a while ago with a group to see if we could make a working mechanical scale that was entirelly 3d printed. Well, we kinda failed in the entirely 3d printed aspect, but hey, it works! It's meant for education purposes or as a normal project, and is our first time designing something like this, and it was designed as part of a school project. Remixes are HIGHLY welcome and needed!

Materials I used:
-Anycubic standard resin in black
-Anycubic PhotonS
-Some cheap aluminum wire I bought at Daiso to attach the counterweight and make the hook in the carriage.
-A counterweight (I used a broken magnetic doorstop I had laying around.)

Post-Printing: See Post-Printing section (I mean come on)

How to use it: Attach the carriage mechanism and counterweight and place scale in the edge of a table with it's flat edge up and wit the beam protuding off the table. Record its starting position and begin taking test measurements with known weights and writing down the scale's displacement. This can be done in a variety of ways:

1. Fold a thin piece of paper into an "L" shape and put the scale on top of it, with one of the L's edges touching the scale and the other going upwards. When the scale has any weight in it that changed its position, it's back side rises a bit: Mark how much it rose in the paper sheet behing it with known weights. Anything thats below a certain line weighs less than the object it represents and vice-versa (assuming you're using the same counterweight).

2. Trace a line perpendicular to the table in the scale's lateral sides. Then use known weights and trace perpendicular lines in each of the positions the scale takes. By the end you should have a quadrant with some lines protruding from the top into the edges of the circular part of the body. When measuring something, trace an imaginary perpendicular line, the object will measure a number between the two closest lines to the one traced.

Please note that the scale tips in a non-linear fashion, in a cosin curve.

Known issues:
-VERY tight toleraces if you print both in the standard file size. I simply forgot that tolerance was a thing until I took my print out. I strongly recommend printing the carriage a tiny bit larger and then sanding it a bit to get a looser fit.
-Carriage mechanism has very thin bottom wall, which means it's very fragile and that you can't drill a hole to place a locking pin on it. If you plan on installing a locking pin, install it from the upside or change the design a bit to your liking.