[Josh] is replacing the springs in his car’s suspension. He wished to understand the travel rates of these springs, however apparently, this is a carefully guarded trade trick in the industry. One business did handle to publish the spring rates, however they weren’t believable. instead of taking this company’s word, [Josh] developed a spring tester.
The theory behind a spring tester is quite simple: apply a force to a spring, determine it, then determine exactly how much the spring has traveled. Or compress a spring an inch or so, determine the force, as well as compress it some more. Either gets you the exact same data.
This spring tester is developed around a Harbor Freight hydraulic press. Yes, the spring is totally caught as well as won’t fly out of the jig if you look at it wrong. The bottom of the press consists of a few tons cells, fed into an ATmega8, which screens a value on an LCD. For the displacement measurement, a ruler taped to the side of the press will suffice, however [Josh] utilized a Mitutoyo linear scale.
What were the results of these tests? You shouldn’t get coils from Bilstein if these results are correct. The rates for these springs were off by 70%. other springs fared much better as well as won’t bind when going over bigger bumps. That’s excellent work, as well as an exceptional application of horror Fraught gear.