Slalom4me

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ghoffman

I guess you could vary the weight to test the shock at different velocities. Having it give you the time for displacement with one weight would not be useful with digressive valving unless you did it several times with different weights.
I am making one like I did in college, that uses a lathe to turn a crank that strokes the shock. In college I used a HP displacement transducer (LVDT), and a load cell. Back then, I used an oscilloscope to see the load versus displacement egg-shaped curves. Now, I will use a PC with a card that can use Matlab software to plot velocity-force, displacement-force or even do a FFT http://www.mathworks.com/access/help...,HPIB:en&q=fft .
The FFT will give you the component velocities and accelerations. The cool thing is a simple crank can work these days with the software available whereas you previously needed a Scotch yoke to get pure sinusoidal motion. I think I will spend about $500 for it, not including the lathe and PC.
http://www.brockeng.com/mechanism/ScotchYoke.htm

Slalom4me

There are some plans here that may be interesting. They appear to
be public domain and might be useful in some way.

Sport Devices

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ghoffman

Very nice, thanks! I like using a displacement transducer instead of the cog wheel for position but perhaps I will use that instead. The reason I want to do the FFT is because it is very common that 2 shocks look identical on a dyno but work very differently on the car. The FFT will change that, because it will recover all of the data not just the first order stuff. It looks complicated but the software does the math.