From: Ben Jackson <>
Subject: Re: Rolling ball info
To: clehman@...
Date: Wed, 23 May 2001 13:23:57 -0700 (PDT)

> The web page you reference is one on Ben Jackson's site, 
> not on my site.  Ben is a member of the
> e-mail list, and for this page he simply used an e-mail
> that he'd sent to the rolling-ball list (headers and all).

I'd never noticed that the version I included only had the list
address and not my own.  I'll try to clean that up.  I've also
been meaning to add a few other posts from my archive to my site
since my views have changed considerably since then.  :)

> > >You talk about a 'slip bender'? I've asked people at various hardware stores 
> > I'm guessing it's one of the various machines to roll/bend
> > metal into ornamental scrolls - these get advertized in
> > Home Shop Machinist and elsewhere.

I got mine from Micromark.  It's 3 rod arranged like this:

       O O

and you feed wire or thin strips of metal between the rollers like so:

      \   /
       O O

(angle of bend GREATLY exaggerated).  The bottom two rollers are connected
by gears so that they turn together, and one has a crank.  You turn the
crank and drag the metal between the rollers which puts in a constant
radius curve.

The one I have supports the upper roller on a frame connected to the base
by 4 machine screws (at the corners) each with a thumbwheel and a hand-
painted "index dot".  To adjust the height you turn all the screws the
same number of turns (you can only let them get about 1 turn out of sync
or it will bind up).  This is incredibly tedious.  There's really no way
to calibrate it, so you can't dial in something like "5 in. radius curve
in mild steel" and get the right setting.  Anything tighter than about
a 24 in. radius is going to require multiple passes, tightening the roller
each time.

You can't easily bend continuous circles or spirals because the material
curves back around to re-enter the rollers.  Even if you allow that to
happen you have no way to get the resulting material off the bender.

The thing is really designed for putting slight curves in small pieces of
flat stock.  You'd go insane trying to bend enough wire for an RBS project.

It's still my inability to shape wire easily that has kept me from doing
much metal RBS construction.