Winding Stair Stringer Issue

Sorry, I think this may have been covered before but I can't seem to find a practical solution for it.

I need to SWEEP the yellow rectangle in this drawing along the magenta 3DPOLYLINE. This is a stair stringer for a winding stair I'm trying to model. The trouble is that when I SWEEP it the rectangle begins to rotate and ends up all out of whack once it gets to the top.

As I understand it, this is something that AutoCAD does not handle well and something like 3DsMax does. Problem is I don't have 3Ds Max and if I recall correctly there is a way to do this within AutoCAD. I just don't understand the SWEEP command options well enough. I've tried setting Align to No and Twist to the 270° that this thing runs, but each time I end up with the stringer rotated out of place.

Winding Stair Stringer.dwg

Twist and Bank perhaps? Not to be confused with Twist and Shout. Although if it doesn't work you might end up with Twist and Swear.

Sorry, I think this may have been covered before but I can't seem to find a practical solution for it.

 

I need to SWEEP the yellow rectangle in this drawing along the magenta 3DPOLYLINE. This is a stair stringer for a winding stair I'm trying to model. The trouble is that when I SWEEP it the rectangle begins to rotate and ends up all out of whack once it gets to the top.

 

As I understand it, this is something that AutoCAD does not handle well and something like 3DsMax does. Problem is I don't have 3Ds Max and if I recall correctly there is a way to do this within AutoCAD. I just don't understand the SWEEP command options well enough. I've tried setting Align to No and Twist to the 270° that this thing runs, but each time I end up with the stringer rotated out of place.

Yup...it's been covered before. You covered it Bill!!!! LOL...here's the thread http://www.cadtutor.net/forum/showthread.php?60635-Sweep-a-Spiral-Stair-Channel-Shape-Along-Spline&highlight=spiral+stair

Busted! it is vuja de, afterall, or should we say beforeall? Might be time to boost your virtual memory allotment. We've all been there for sure.

In AutoCAD 2012 extrude the 3d polyline to a suface, then offset the surface to the needed thickness using the solid option.

Simple but elegant. Great idea dedmin.

Ok, thanks for the tip. But I only followed you correctly until the second step. I have extruded the 3D Polyline as a surface. But I don't follow the next step of offset or solid option. Can you elaborate a little more on that part?

To insure I did the first step correctly, I did:

EXTRUDE

MODE

SURFACE

Then I selected the 3D polyline and gave it a height of 16. I would like the stringer to be 2" x 16". I should also note I did this operation with the UCS set to W. I have now a nice surface which follows the 3d polyline but I don't follow the next step too well.

Bill: You have to find and use the THICKEN command on the Solid Editing panel of the Home tab.

Jack, yes I looked back at the other thread...must be having another senior moment. I was able to us THICKEN after I got the surface extruded and it's shaping up better now. I knew there had to be a way of doing this in AutoCAD, not just Inventor or 3DsMax.

I will try next to smooth out the stringer surface as it looks too segmented for Presentation work.

So has anyone ever heard of this website: http://www.stairporn.org They don't have any porn there, just stairs and if you're into designing stairs like I am, this is an amazing site for information and ideas. Funny URL though!

We aren't going to fall for that (stairporn) Bill but nice try anyway.

Lol Bill...happens to me all the time. One of the perils of being over 50 in my case. To smooth out your "segmented" look, change the facetres variable. Min is .5 (default), max is 5.

stair porn? lol thats hillarious

Stair porn. It's all about the "risers".

Stair porn. It's all about the "risers".

Adds a whole new meaning to "getting up in the world".

And this is called a "hand rail".

I wouldn't lie to use guys now would I?

I do lot's of ornamental work, that is when someone's paying me...which is rare these days. But I've done a few stairs in my time and the method to make them out of metal is pretty well known to me. The method to make them out of wood, especially the helical and elipitcal types are amazing to examine. Most people never think about what's under foot when they walk up a flight. But we know different.

I wouldn't lie to use guys now would I?

 

I do lot's of ornamental work, that is when someone's paying me...which is rare these days. But I've done a few stairs in my time and the method to make them out of metal is pretty well known to me. The method to make them out of wood, especially the helical and elipitcal types are amazing to examine. Most people never think about what's under foot when they walk up a flight. But we know different.

I'm sure you've seen this before, but if not, check it out: http://www.lorettochapel.com/staircase.html

I haven't had the opportunity to see it in person, but its on my list to do.

I've not been to the site yet, and this may well be on there, but if it isn't, it probably should be............http://www.youtube.com/watch?v=9bodDIpV1hk&feature=related a nice bit of work, they should last a while.

I've not been to the site yet, and this may well be on there, but if it isn't, it probably should be............http://www.youtube.com/watch?v=9bodDIpV1hk&feature=related a nice bit of work, they should last a while.

That is pretty cool work. They said the treads weighed 300 pounds each. Amazing.

this is a pic of the Loretto Chapel staircase. It touches the floor and the balcony, and nothing else. Built in 1878 by one man with a box of hand tools.