Ratio-reading Balance Scale

This balance shows the ratio between two objects, from 0 to infinity.

• You can use this balance as a normal scale with a fixed weight.
• All parts can be printed out without support. Printable with 200mm x 200mm printers.

Video

How to make

You need

• Steel wire for pivots (I used 1.7mm wire)
• Eight 3mm tapping screws
• Soldering iron to fix the pillar to the base plate
• Small nuts for balance weight
• Large bolt and nut (I used M12) for counter weight

Howe to make

1. Print parts.
   • Lighter is better.
   • Print beam.stl and tray.stl double.
   • All parts can be printed out without support. "tray.stl" should be set so that the oblique outer side facing down.
   • To print the index.stl, use "pause at height" function to give different color to the texts.
2. Preparation of parts.
   • Clean holes with a drill for smooth rotation.
   • Remove debris and burr.
3. Assemble all parts.
   • Fix pillar to the base plate with soldering iron. Make sure the pillar is vertical.
   • Insert 1.5mm - 2mm steel wire for pivots. To fix the wire, bend one end slightly.
   • Fix needle and counter weight holder with 3mm tapping screws.
4. Adjust the balance.
   • Firstly, attach main counter weight (large bolt and nut) to adjust the center of gravity to the rotation axis. In other words, The balance should be stationary at any position if there are not payloads. This step is important to show correct ratio. If the counter weight is too light, shown ratio is lesser than actual, and vice versa.
   • If one side is heavier than the other, stick some weight at the back of the tray.

Principle =========

Category: Household