On 8/5/2008 9:14 PM Dennis Haynes wrote:

> Sure it could be done, bring money.

Aw, 3D accelerometers are not expensive, consider the Wii controller. I've
used cheap polymer film piezo transducers in the past, the output of which
could go to the input of my existing Picoscope oscilloscope box that
connects to the laptop via USB. I just don't think I can get even a 1-axis
accelerometer in the time I have remaining.

Wait - I might be able to find a stick-on piezo pickup for guitars,
upright basses or cellos at a music store nearby.

Or, use a Radio Shack piezo mic, like shown here:

http://home.earthlink.net/~erinys/contactmic.html

And stick it to the body of the trailer with double-sided foam tape.

-- Mike RJS

>
> One thing about trailer tires, inflation pressure needs to set by the
> load. They are small and they spin fast and they are poorly made and they
> love to blow out. Squishy trailer tires are guaranteed failures, even
> small ones.
>
> Dennis
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Mike Elliott
> Sent: Wednesday, August 06, 2008 12:06 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: [NVC] Engineers: quick and cheerful vibration analysis?
>
> This is a question for the engineering geeks here.
>
> Say you were towing a little trailer behind your Vanagon. Say that the
> trailer had a rudimentary suspension consisting only of leaf springs. Say
> that this trailer also had tires, the pressure of which could be adjusted:
> higher pressure results in a harsher ride, while lower pressure results in
> a softer ride. Say you wanted to determine the optimum pressure of ride vs
> tire squishiness but were unable to find a small boy to ride in that
> trailer to report back about smoothness of ride v tire pressure while the
> experiments were being conducted, so lacking that small boy, your thoughts
> naturally turn to instrumentation. Okay, so say you had a laptop computer
> (WinXP) which could ride in the passenger seat, and /three/ business days
> in which to acquire the needed sensor (accelerometer?) as well as the
> software to display the ride bounciness.
>
> Could it be done?
>
> --
> Mike "Rocket J Squirrel" Elliott
>