Date: Wed, 4 Aug 2010 14:47:28 -0700
Reply-To: neil n <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil n <musomuso@GMAIL.COM>
Subject: Was: Re: Swage Bit ... Pop Top Cable. Now: more info
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Hi all.
So. I went to Pro-Tech Yacht Services Ltd here in North Vancouver to
look at parts and get an estimate of cost to make a custom cable. One
of the techs was kind enough to go through the motions of giving an
estimate. @ $7x Cnd/hour, and $10 a swedge, making one cable would be
at least $100. Thats almost twice the dealership price! <grin>
Of note, no one had seen that "Z" swage fitting before. I googled for
several hours looking for that fitting. Nada. The cable guy thought he
could bend a 316 SS swage eye type fitting to follow the radius on the
lower arm. I'm no expert, but I'd suggest NOT doing that. Just a gut
feeling based upon some p-mails with Alistair. He did however, offer
an idea for the other end that pulls up on spring; a swage with ball,
(kinda like this: http://www.savacable.com/pages/im/im_2_03b.gif)
that would seat in a countersunk hole in head of a hollow bolt. (kinda
like this, but no washer. Bolt head ~ same OD as OEM:
http://www.kuryakyn.com/Kimages/item/MainProduct/2389-2.jpg) This
*might* allow enough room between it and the pin holding lower arm to
bracket on body. *Might*. Eyeballing things, assuming the spring is
slightly compressed when top up, maybe. Also, one could cut a coil off
the spring. But.....
All that leg work and googling + the $100 or more makes me think one
would be wise to get the Jack Bombay gas cartridge kit:
http://www.thesamba.com/vw/classifieds/detail.php?id=798951
In fact, I bet I could make something like those brackets. We'll see.
David. Thanks for the thoughts, tips and link. As per your comments,
I originally could see how this part had to be made 100% "right". My
guess is that the cable (wire rope) would be prone to failing when
lowering the top (compressing the spring) Even just having it "fall"
on me during last portion of lowering was cause for a possible stain
when it happened to me. ;)
For anyone attempting this, this is the most promising idea I could
see for the end of wire rope at curve:
http://www.aeroassemblies.com/images/wirerope/WR1.jpg or a wire rope
thimble with bolt/nut/washer. The other end, as per above, or, drill
out the stock piece and swage a stopper on cable poking out end.
I guess anything can be made, but my advice is go with something more
modern and easier to get future parts for. :)
Neil.
On Wed, Aug 4, 2010 at 1:41 PM, David Beierl <dbeierl@attglobal.net> wrote:
> At 12:03 AM 8/4/2010 Wednesday, neil n wrote:
>>
>> Would bending this stainless part ~ 45* weaken the metal to much to be
>> useable in this application?
>
> I'd like to suggest you think (and measure) very carefully about this.
> These fittings are intended to be used in pivoting applications where the
> tension is always along the axis of the fitting. If there is even slight
> repetitive bending of the wire where it exits the swage it will be liable
> to early fatigue failure. I'd suggest that it *might* be better to shorten
> the fitting to keep the exit point where it is in the original, and also to
> consider the thickness of the fitting and how it affects the lead at the
> exit. If the joint is absolutely static under operation these considerations
> are much less, i.e. I don't see a one-time small-angle bend to pose a major
> problem. The fitting has a working load of ~250 kg at 3:1 margin, and the
> eye is the weak point -- clearly a swage length at least as long as the
> original should suffice. I presume you'll be using 7x19 wire for
> flexibility -- 1x19 isn't meant for running over sheaves.
>
>
>> Would a 5 mm bolt in that application be strong enough not to shear?
>
> Here's a page that will help you calculate the shear loading:
> http://www.roymech.co.uk/Useful_Tables/Screws/Bolted_Joint.html
>
> To get useful answers I think you'll have to determine the spring rate
> (force per unit compression) and total compression.
>
> Yours,
> David
>
>
--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"
http://tubaneil.googlepages.com/
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
