Shape bender distortion

I’ve finally put together a workable surface for this reproduction of spiral staircase step, but a crucial last step is staying tantalizingly out of range; I need to radially bend the two “wings” (with the decreasing circle arrays) underneath the central triangle, as the metal shop who made it had to do…
Shape Bender will do this, but at he cost of severe distortions that result in the “tiling” losing its workability, in that I can’t assemble the resulting geometry anymore, whereas it was a cinch before this problem arose.
On top of that, the necessary second fold, as two are required, is impossible to figure out.
Any thoughts or alternative extension suggestion?

Could you share the SKP file with the flat stair step and a curve showing the shape it is to be bent to?

The file won’t load,
Surprising to me; It’s only 3.3 megs. Here’s just the curve, in case it helps…
just the curve.skp (13.8 KB)

Did you purge the file before trying to attach it.

The forum limit for uploads is 3 Mb.

As Box asked? Did you purge the unused stuff from the file?

The curve by itself isn’t much use.

saving in previous versions sometimes helps reducing the size, for some reason… if it’s 0.3 mb too big that might do the trick

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How do I do that? Help only refers me to Fredo’s Purge obsolete files…

Window/Model info/Statistic and hit the purge unused button.


Done. The Finder still says 3.3 megs.

Upload it to the 3D Warehouse and give us the link.

Done. I’m glistenUp in the Warehouse.

Are you just trying to create a radiused 90° bend down the length of the tread plate? Or is it supposed to be bent into a U-shape? Your setup isn’t correct for Shape Bender but I’m trying to figure out how you want it bent. Do you have a photo of this part?

Coming right up…

The picture weighs 3 times the .skp file…

Do you know the radius of the bend?

Do you realise all these bumps are going to kill your model. Why not just use a checkerplate texture.

Outside radius is 1/2", with the plate being 1/4" thick. The non-flat part of the curve I sent you is of that size…
Sorry, I meant 5/16" thickness… Also, I should’ve mentioned that the curve I sent you is for one of the two required bends, as in one 90˚ bend for either side of the stair…

I figured I’d make my own, which took some doing.

One way to work with it would be Fredo’s Radial Bend, part of Fredoscale.
Mind you it will take some work and you may need to Isolate the loop at the end and put it back on after bending, and you’ll have to repair some holes.
I drew an edge to align the tool, and I have edited out a lot of the waiting time in the bend process, so don’t expect it to be quick.


I’d already cut the tip of the stair off so it would stay straight. The holes are a snap to repair with the geometry I built. Looks a lot like Shape Bender, but with a lot better interface. I should manage.
Thanx a heap… Box says I’ll “kill” my model by not using a texture. The point isn’t the model, it’s the working out of the problems.