You could use a clip-on transducer, meant to plug in to a tuner.  Prolly $10

On Wed, Aug 6, 2008 at 7:46 AM, Mike Elliott <camping.elliott@gmail.com>wrote:

> 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<http://home.earthlink.net/%7Eerinys/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
>>
>>

--
Jake
1984 Vanagon GL
1986 Westy Weekender "Dixie"
Crescent Beach, BC
www.crescentbeachguitar.com
http://subyjake.googlepages.com/mydixiedarlin%27