Date: Fri, 8 Aug 2008 17:26:12 -0600
Reply-To: Tom Buese <tombuese@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Tom Buese <tombuese@COMCAST.NET>
Subject: Re: [NVC] Engineers: quick and cheerful vibration analysis?
In-Reply-To: <489CD089.10203@gmail.com>
Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
Mr. Squirrel,
I can't believe you have time to beat this issue to death when you
are leaving in 2 days? You must be completely packed & ready to go?
LOL,
Mr. BZ
On Aug 8, 2008, at 5:02 PM, Mike Elliott wrote:
> Well. Yes. Of course. One /could/ use such a *sniff* low tech
> approach.
> One might as well plant a small boy back there with a video camera,
> Blair
> Witch-style, and review the tapes later.*
>
> There is something about your solution that I like: it appeals to
> my inner
> R. Goldberg. But my inner Mythbuster (read: Grant Imahara) wants
> accelerometers and graphs.
>
> I, personally, would combine your approach with my approach
> (subjective
> ball-watching v geeky graphs and stuff AND would add to it some
> means to
> inflate/deflate the tires remotely while in motion as well as sense
> and
> report back sidewall temperatures. I'm telling you: with sufficient
> funding this could quickly mushroom into a completely absurd project!
>
> ====================
>
> * Actually, if that wasn't so darn dangerous and illegal, it would
> be a
> great way to evaluate tire pressure v ride harshness!
>
> --
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus -- NOW SOLD TO THE BUYER OF OUR HOUSE
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> KG6RCR
>
>
>
> On 8/8/2008 9:41 AM Jim Akiba wrote:
>
>> For what you're trying to do, software, sensors and data are way
>> overboard I think. Match the solution to the problem... you simply
>> want to be able to verify that at X tire pressure you do or don't
>> have
>> an additional level of "bounciness" whatever that means correct?
>>
>> What not just grab a cheap video camera, some bungees, a plastic wide
>> mouth jar big enough for a tennis ball, a ping pong ball, and a
>> softball for example(you might need something much heavier/lighter
>> depending on the displacement and frequency of bounce). Put the tires
>> at X pressure, write that on a piece of paper and "show" this to the
>> running camera(to link that tire pressure with the video with
>> certainty) that is now strapped to the trailer and recording the ball
>> in the see through plastic container. Ride in a set path that you
>> will
>> repeat at whatever speeds you would like. Concentrate on road safety
>> and consistency in driving. Change the tire pressure a few times and
>> repeat. Simply watch the tape, and "see" what you can see... You
>> could likely run this test and have an idea of what you want in the
>> same amount of time it would take to track down a good sensor for
>> cheap, install the software, run the test, and analyze the data.. and
>> I'm almost 100% certain that interpreting the simple visual data will
>> be much more intuitive for your average bear than raw numbers...
>> especially if you aren't sure of what range of displacements and
>> frequencies you're starting with(which you would really need to
>> ballpark to even pick the correct sensor)
>>
>> Hope this helps,
>>
>> Jim Akiba
>>
>> On Wed, Aug 6, 2008 at 12:06 AM, Mike Elliott
>> <camping.elliott@gmail.com> wrote:
>>> 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
>>>
>>
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