Spiral Stair case problems

I have read all threads on this topic and can't find what I am looking for. I have a Stairway going up the side of a large tank the treads are no problem to organise but the stair is not attached to the tank so the stringers are giving me problems. I have tried to sweep the stringer profile along a 3d poly (which is the wp's of the treads) but the stringer profile a 200 X 10 Flat is not following the path of the 3dpoly correctly the top edge seem to be ok but the bottom edge kicks out ie is not parallel with the top around the curve this also happens to me when I extrude or sweep the profile along a helix.

can anyone help:o

Attach the file here.

note this is only the first flight due to the size limit of the file

Cheers

Nik

Ps thankyou for even replying to my thread other forums I have visited have not done so. I will be sticking to this one I find it very informative and you guys seem to know your stuff.

stairway1.dwg

MEP has the stair tool right? Can you try to create the stair off custom line work and get it to work? (right click on the stair tool in the palette, apply properties, then line work follow the command line and whala.

excuse my ignorance but can you tell me where that I would find that tool

cheers

Nik

excuse my ignorance but can you tell me where that I would find that tool

 

cheers

 

Nik

I dont happen to know MEP, but you should be able to find it by doing a search in your content browser.

yeah I tried that buddy to no avail, I have just settled that I have to do it the old fashioned way with a whole lot of time consuming geometry. But thanks anyway mate

Cheers

Nik

I've checked your file, I think the problem is your steps aren't really all concentric. There are also some differences in hight between the steps.

The easiest way to solve this (without touching the actual steps) would be to copy the 3D lines you've already traced and place them exactly 200 units underneath the first ones (in Z-direction). Use LOFT to turn them to surfaces, then simply thinken them.

Hope it helps!

I forgot: turn your 3D lines into Splines before lofting them to surfaces...

mafalda, Thankyou very much, i have the surface but now how do I thicken it.

cheers

Nik

There should be a command in the "Modify" menu, under "3D operations"!

I can't find it in Autocad 2009 Mech. but I will open the model in 2007 and try that. Thanks for your help.

just typed it in and it worked in 2009 Thankyou very much

Nik

Hmm.. try this:

put "_Thinken" in the comand line.

Haha, I came too late!

Ok, great, it works

Bye!

MEP has the stair tool right? Can you try to create the stair off custom line work and get it to work? (right click on the stair tool in the palette, apply properties, then line work follow the command line and whala.

FYI MEP is a different package to Mechanical...