Date: Fri, 18 Apr 2008 09:03:05 -0700
Reply-To: neil N <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil N <musomuso@GMAIL.COM>
Subject: Re: tube bumpers
In-Reply-To: <0FC71263A4B9452E8685293F423D2638@ownerPC>
Content-Type: text/plain; charset=ISO-8859-1
Good points Gary.
I was just looking around youtube to find the video I mentioned, and
just learned the difference between the term "pipe" and "tube". Tube
being the thinner wall stuff. You'd think I already knew that!
I recall working (apprenticing) making trombone bells. We did it old
school! We made the bell, tuning slide, rings, braces, lead pipe, and
arm all inhouse. Everything but the slide and case.
As for bending, the conical tube for the tuning slide was filled with
lead, bent on a jig (by hand). (of course it was annealed first.....
and the seam was bronze brazed) As it was bent, it was removed so the
high spots could be tapped down. Then bend. Repeat. THEN we used a
hardwood chunk (a section from a tree trunk. Really!!) as a base and
using hooks and a hammer, we "rounded" the piece out some more, then
we would go to the filing, emery, buffing stage. I might not be
recalling all the steps involved, but just for that part, it was
somewhat labour/time intense.
Don't even get me started on how to spin the bell!!! Or "worse" yet
bronze brazing the seams or planing them!!!!
--- ;^)
Neil.
On Fri, Apr 18, 2008 at 8:39 AM, Gary Lee www.vwrack.com
<gary2a@telus.net> wrote:
> >
> > I posted the plans to the Tiico Group thinking id just buy a $65 HarborFr8
> > pipe bender and MIG away >until i had an exact copy of the
> >
> > BullBars......turns out i need a hydrolic Mandrel bender, im still waiting
> > for >Harbor Freight to make one of those for $200...LOL:)....not holding
> my
> > breath.
> >
>
> Bending tube isn't cheaply done. Especially large diameter thin wall
> tubing
> like what we want for vanagon bumpers. You definitely need a mandrel
> bender
> which costs tens of thousands of dollars. And no, muffler tube benders do
> not work. You need a mandrel inside the tube to keep the walls from
> collasping. The bends need to be a tight radius and the wall thickness
> needs to be thin to keep the weight reasonable.
>
> The Harbor Freight/Princess Auto benders are for heavy wall schedule pipe
> only, gas pipe. I wonder how many people buy them thinking they can make
> exhaust systems and roll bars. You can't even make handrails with them. I
> don't know what people use them for. Further, the dies are sized for pipe,
> not tubing.
>
> Gary Lee
>
--
Neil Nicholson. 1981 Air Cooled Westfalia - "Jaco"
http://web.mac.com/tubaneil
http://tubaneil.googlepages.com/
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