Date: Fri, 8 Aug 2008 21:06:04 -0700
Reply-To: Mike Elliott <camping.elliott@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Mike Elliott <camping.elliott@GMAIL.COM>
Subject: Re: [NVC] Engineers: quick and cheerful vibration analysis?
In-Reply-To: <AD871BC0-2C27-4334-A935-C76B15050DC5@comcast.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Xenon.
--
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 7:51 PM Thomas Buese wrote:
> On Aug 8, 2008, at 5:39 PM, Mike Elliott wrote:
>
>> Mr B-Z,
>>
>> I have been sorting and packing for the past three months. I'm
>> rounding
>> the last turn of the racecourse, and am--even as I write this--
>> taking a
>> well-deserved break. This is like packing for a long backpacking
>> trip, or
>> a camping trip: I make lists, I sequence things. I overprepare and
>> overthink things, but I'm usually pleased that I seldom forget
>> anything or
>> bring more than I need. I am, in short, ideally-suited to pack up a
>> house,
>> a family, and a business, and move them, my stuff, and myself 1,000
>> miles
>> while craftily leaving the hard work (loading the ginormous 26-foot
>> Penske
>> truck) to wife and family. Admire me, gentlemen. As you see, the way
>> I do
>> things, I leave plenty of time to wonder about The Big Things, like
>> this
>> dead horse.
>
> I am so jealous of your organizational skills-On to Bend w/ the proper
> air pressure!
>
> grin,
>
> Mr BZ-are you using nitrogen in your tires?
>
>
>
>
>>
>> --
>> 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 4:26 PM Tom Buese wrote:
>>
>>> 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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