coil jack

Using the rotational equilibrium kit https://www.thingiverse.com/thing:5349742, we add a small magnet to one side of the balance. Under that magnet, we placed a wire coil on a jack stand. The stand allows the user to raise and lower the coil. Applying a voltage to the coil creates a magnetic field that attracts or repels the small magnet on the balance arm. The masses are moved on the opposite side to bring the balance back into equilibrium. From the change in position, the magnetic force can be calculated.

Parts are separated to eliminate supports.

Key shaft is glued into the jack base. Glue follower to the bottom of the coil holder.

The screw is a 4mm pitch and there are markings at 45 degrees on the screw. An alignment notch is on top of the base. Rotating the coil from notch to notch changes the height by 0.5mm.

Source for coil kit: https://sci-supply.com/primary-and-secondary-coils-small-student/