Spiral Staircase

[Hitch]

Not made one like this for sometime. Nothing spectacular.

All welded up, none of this adjustable tread stuff. Handrails fit on after.

Last section of rail to fit at the top. The shape of the posts makes them look as if they are leaning, keep checking them.

Joints, the rods are supposed to slip into stopped holes in the posts. Temporarily spragged to hold it in place. Enough movement in the finished panels to allow the joint to separate. Some site welds required i'd think.

Some kind of floppy whale rib cage.... Or the handrails. Temporary ties across the bottom to help keep their shape.

 

[fixerupper]

Looks great , I like the profile of the uprights ... nice work .. jeff...

 

[Bobtail4x4]

er how do you avoid the "not readily climbable" bit on the guarding?

 

[balmerchris]

How do you measure the treads so that by the time you get to the top your not way out? Do you use a plumb line?

 

[Hitch]

I gather that part of the reg's doesn't apply where it will be going.

Not a public place or anywhere children will be.

 

[balmerchris]

I like the piece of pipe welded to the truss to hold the center pipe :-)

 

[Hitch]

How do you measure the treads so that by the time you get to the top your not way out? Do you use a plumb line?

I put the treads on with the post laid down. Make a wrap of the tube from flat sheet, mark it up into segments. Roll the wrap so it fits nicely round. Use the seam as a fixed point, mark off the various heights along the tube, then mark the segments, starting at the seam. Every marked segment can be checked for position against the seam, so it stays pretty constant. That gets the narrow end in the right position.
Then its a matter of working out the correct angle for the front of the tread. 0,(horizontal), 22.5... 45...67.5... 90(vertical)

Easier than it sounds.

 

[Hitch]

I like the piece of pipe welded to the truss to hold the center pipe :-)

Only clamped up there... allows the whole thing to spin with ease, save keep moving welders around, just rotate the staircase.

 

[chunkolini]

I love spiral staircases.
I say though chaps shouldn't they be called helical staircases.
Great things the way the load passes down to the bottom, I remember as a kid suddenly understanding how they work in some crumbling pee stinking castle.
None of the adults had a clue what I was on about.
That is a very sensible 'cheat' on the sloping railings.

 

[Hitch]

Helical stairs are a bit different Chunko....and..after a bit of tidying up

 

[chunkolini]

Surely a spiral rotates outwards from a centre, a helix rotates around a focus on a constant radius..
Picture shows is a double helix.
Hell I never walked up a spiral staircase as a kid, it was helical.
Do I detect a bit of pedantry here?

 

[Welderpaul]

Helical stairs are a bit different Chunko....and..after a bit of tidying up

Ha, i remember fitting those - that was a few years ago!

 

[Hitch]

Surely a spiral rotates outwards from a centre, a helix rotates around a focus on a constant radius..
Picture shows is a double helix.
Hell I never walked up a spiral staircase as a kid, it was helical.
Do I detect a bit of pedantry here?

If you think of it like that, you have a point there

 

[balmerchris]

I put the treads on with the post laid down. Make a wrap of the tube from flat sheet, mark it up into segments. Roll the wrap so it fits nicely round. Use the seam as a fixed point, mark off the various heights along the tube, then mark the segments, starting at the seam. Every marked segment can be checked for position against the seam, so it stays pretty constant. That gets the narrow end in the right position.
Then its a matter of working out the correct angle for the front of the tread. 0,(horizontal), 22.5... 45...67.5... 90(vertical)

Easier than it sounds.

Very clever wouldn't have thought of a sleeve. how do you find your angles then? with one of those fancy angle finder doofers for bench saw's?