I am attempting to figure out why a laser layout tool I have is drifting over time. It was designed with a small adjustment mechanism that relies on a spring to apply pressure to a fulcrum that rotates the entire laser. A screw is used to apply and release pressure on the spring thus moving the laser very small amounts left and right.
I am getting a drift in the lasers horizontal position of about 1/2inch at 100 feet over the course of several hours. I am doing this test at night and there is about a 15 degree Fahrenheit temperature from when I start the test to when it is complete.
I made a Sketch-Up model of the device and determined that 5 micron change in position (at the end of the fulcrum) is all it would take to move the laser 1/2 inch at 100ft.
My question is it possible that my spring is expanding and contracting 5 microns with a 15 degree temperature change?
I am not an engineer and am looking for some speculation just to rule in or rule out the general possibility.
The spring looks similar to this:
The diameter of the entire spring is about 1/4 inch. The diameter of the coiled metal wire is about 1/6 inch. The spring length is about 1/2" uncompressed. It consists of about 8 loops.
I do not know the metal it is made of, speculation on different scenarios would be helpful as, again, I'm just trying to rule in or out the possibility.