[TheForge] Spiral stairs? (Was: horn)

[Ralph Sproul]

Hi Mike,  I did an interesting spiral stairs a number of years back.  It was
a 4" diameter pipe that we fastened to the floor and made a bracket to tie
it to the roof rafters.  I then used a circle cutter on a clamp on jig to
cut radiuses in the ends of 1/4 x 4 x 8 tubing.  This I stacked and tack
welded as I went and used 1/4 x 1 1/2 x 1 1/2 angle iron from the tubes top
to the bottom of the next riser and welded them to both.  This gave a great
place to bolt the treads.  The end of the tubes I capped with 3/8 material
and forged balisters for them that went up to angle irons on top welded at
the stair's slope.  We then clamped black walnut and oak in alternating
laminates to the angles and formed the handrail helix .......messy but nice.

Of course you've got to figure the rotation of the spiral for entry and
exit, where your top landing is, and the funny thing is the rise on the
stair case is the angle cord for the number of treads it takes to do a 360
degree turn......meanind if you've got 12 treads to go round one turn then
the angle is 30 degrees..... which when you lay it out is a short distance
from one leading edge of the stair tube to the one above it - but when it
fans out to the end of the tread - there is some distance there.  We had to
go up quick so we used 8" tube.  It might be nice to use 6" tube with 1"
treads and end up with a comfortable 7" step.  The trick is to figure the
total rise, divide by a comfortable number that works for riser and tread
thickness, then the run is the number of those rises to get you to the upper
landing - and that gives you were you'd enter with (1 turn, 1 1/2 turns,
etc) - this is given as an example - doing the math and figuring to the site
is where it all comes to light.

We used tubing because the guy had about 40 feet of it - so we didnt' have
to buy much - but angle iron, channel, formed pans, etc all would work out.
You could do like the kits if your looking for utility only and do a tread
to a pipe that slides down over the main shaft and stack and weld em.

    ...........and no, I don't have pictures dam it.  One of those "I'll get
em next time" and never went back again to the place we did the stairs at.
I left when it looked like a stalagmited spider web with all the glue
streamers and drips - but I hear it came out nice when they planned the rail
and took the construction paper off the treads, landing, and floor below.

Ralph

----- Original Message -----
From: "Mike Spencer" <mspencer at tallships.ca>
To: <theforge at mailman.qth.net>
Sent: Monday, July 04, 2005 12:31 AM
Subject: [TheForge] Spiral stairs? (Was: horn)


>
> Any suggestions for method of construction for a spiral [1] stair?
> For my own use in the shop, pure utility.  I have thoughts, have done
> sketches, diagrams, calculations etc. but pointers to gotchas or
> prefered methods would be welcome.
>
>
> And on the matter of the anvil horn:
>
> > Given this capability, it turns out that its possible to simply hold
> > the work and the hammer while cursing as rapidly as possible to
> > perform ordinary forging operations.
>
> I love it.  Do you suppose we could hack it to work in reverse?  Forge
> out something really intricate (say, a rose from solid bar) or really
> massive (say, a ship anchor) and translate it into corresponding
> ...um... strong verbal reproofs which would be blasted from speakers
> for the benefit of unwelcome onlookers or perhaps recorded for later
> similar use?
>
> My anvil horn points west but I have a rare earth magnet from a
> computer HD stuck to it to rotate its magnetic field, so I'm okay.
>
>
> - Mike
>
> [1] Yes, I know the the difference between spiral and helical.
>     Pedants should s/spiral/helical/g supra.
>
> --
> Michael Spencer                  Nova Scotia, Canada       .~.
>                                                            /V\
> mspencer at tallships.ca                                     /( )\
> http://home.tallships.ca/mspencer/                        ^^-^^
>
> --
>
>
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