Date: Tue, 4 Mar 2008 13:59:05 -0800
Reply-To: Michael Elliott <camping.elliott@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Michael Elliott <camping.elliott@GMAIL.COM>
Subject: Re: Poptop Raise Assists
In-Reply-To: <DE218296-799B-4185-928C-D056EFE21158@mac.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Thanks, Kim, for the link to the pictures. Yeah, I can see that struts
back there don't have much mechanical advantage.
As you mentioned, http://www.mcmaster.com/nav/enter.asp?pagenum=1167
shows a handy formula for calculating force.
I'd like to plug in some numbers and play a bit. To do so, four
variables need to be provided:
W = weight of object to be moved (poptop),
Y = distance from gas spring mounting point to center of object to be
moved (poptop, again)
Z = distance from hinge to mount point on, you guessed it, the poptop, and
N = number of springs to be used.
The geometry of the rear hinge on the poptop is a bit complex, as it
throws a virtual hinge point behind the vehicle, so that needs to be
determined by eyeball, I reckon.
What does a poptop weigh, anyway?
--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
KG6RCR
On 3/4/2008 1:37 PM Kim Brennan wrote:
> 250 pounds struts might not lift 250 pounds on top of your westfalia. It
> depends on the angle of work among other things. The info on McMaster
> can help a lot. You can use struts that have a lot less lifting
> power....if you mount them differently than I. Mine was almost a worse
> case scenario (which is why I have 2x250 pound struts). In my case it
> helps lifting (a bit) and more importantly gives a LOT of protection
> when lowering the top (so all that weight doesn't come crashing down on
> my head when lowering it.)
>
> <http://homepage.mac.com/kimbrennan/PoptopAssist/>
>
> The above is a link to photos I took showing the struts installed.
>
> On Mar 4, 2008, at 4:18 PM, Michael Elliott wrote:
>
>> Kim,
>>
>> Like Joy says: we want details. I wouldn't mind a little assist even for
>> my unladen poptop. The old "arthuritis" in the right shoulder makes
>> lifting the top a bit painful. 50lb of lift would be right peachy, I
>> betcha. Just need some idea how to mount the things.
>>
>> --
>> Mike "Rocket J Squirrel" Elliott
>> 71 Type 2: the Wonderbus
>> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
>> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
>> KG6RCR
>>
>> On 3/4/2008 12:25 PM Kim Brennan wrote:
>>
>>> Yes, I used 250 pound struts that I got from McMaster-Carr.
>>>
>>> I believe I used 9416K54.
>>>
>>> However, part of that choice was dictated by my particular needs.
>>>
>>>
>>> On Mar 4, 2008, at 1:55 PM, Keith Ovregaard wrote:
>>>
>>>> Hey Joy
>>>>
>>>> I've been thinking about putting some assist struts on my poptop for
>>>> some time now, so I am glad you brought it up. Kim Brennan and I
>>>> emailed back and forth about a year ago and he seemed happy with the
>>>> struts mounted to the poptop brackets. I think they were 250lb.
>>>> struts. Kim, do you have a part number? Did you get the struts from
>>>> McMasters?
>>>>
>>>> Keith O
>>>>
>>>>
>>>> On Mar 4, 2008, at 4:01 AM, Automatic digest processor wrote:
>>>>
>>>>> Date: Tue, 4 Mar 2008 06:57:48 -0500
>>>>> From: Joy Hecht <hecht.joy@GMAIL.COM>
>>>>> Subject: Re: Poptop Raise Assists
>>>>>
>>>>> Yup, I know I'm replying to an email from more than a year ago! But
>>>>> I'm
>>>>> back to carrying a kayak, and thus back to being unable to lift my
>>>>> poptop.
>>>>> Very inconvenient. So I'm looking at struts.
>>>>>
>>>>> Kim, why did you install them inside instead of outside? Is that
>>>>> cosmetic
>>>>> or functional? And I can't tell from your photos where exactly they
>>>>> are
>>>>> mounted at the lower end. Are they attached to a metal plate that
>>>>> is part
>>>>> of the poptop hinge?
>>>>>
>>>>> If anyone else has tried this, I'd be interested in your experience
>>>>> as well.
>>>>>
>>>>>
>>>>>
>>>>> Joy
>
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