RC Shock Spring Gauge

thingiverse

I own numerous 1/10th scale touring car shock springs from various manufacturers. I sought a method to compare these springs and measure their actual spring rate, so this is what I came up with. I designed brackets that fit perfectly on my caliper (Wiha DialMax). And here's how it works: 1. Attach the brackets to the caliper 2. Insert a spring into the bracket 3. Read the initial length of the spring (27.5mm with the black spring) 4. Set tara, or zero out the scale, by placing the caliper on top of the spring 5. Compress the spring 5mm (or more if your scale can handle it), pushing directly from above on the upper bracket 6. Read the weight of the compressed spring (1254g, which equals 12.54N) 7. Calculate the spring rate using this formula: D = F / ΔL Applying this to the black spring: D = 12.54N / 0.005m = 2508N/m The same process is used for the purple spring: D = 6.77N / 0.005m = 1354N/m This reveals that the purple spring has a stiffness just over half that of the black spring.