Here it is:
Arduino Mega (overkill but I had handy).
Two load cells (5kg max) and HX711 readers.
OLED (SSD1306 32x128 pixels)
Battery holder 4x AA
Screws (M3) allow pushing in small increments, and rubber bands pull back on the mechanism so that I can measure positive and negative (pulling) forces with a single setup.
Measurements are in pounds, with decimals down to 0.001 pounds (milli-pounds 
).
I haven’t set up displacement measurement yet but I did discover my tool mount was cracked. I felt like the stiffness was worse than it should have been (based on feel) and here I was blaming it on other things…
Pulling on it to make it obvious:
Definitely need to fix that before measuring again.