Spiral stair rails

i have uploaded a drawing of spiral stair rails (because the fille was to big to upload all of the drawing) i am absoloutly stumped on how to get a poly line going on top of the rails in a nice curve so i can extrude a handrail i have downloaded a helix lisp but i still can't do it any suggestions anyone

many thanks sceejays

SPIRAL STAIRS.for cad forum.dwg

Did you try extruding along a spline?

the problem im having is getting a spline or polyline to go on top of the rails in a nice curve to enable me to extrude a handrail along it

so really im stumped on the first thing i have to do

sceejays

I just snapped the SPLINE along the top at the center of each post, went around smooth, and Extruded a circle the length of the spline, using the Path option.

this was interesting so I thought I'd use it for an excersize, I got the Spline from the top of each post but can't get any object to extrude along the spline. I get this " Cannot extrude along 3D spline path."

EDIT: Not 100% sure how I got it but had to use sweep.. COOL !

I had no problem with it.

I had the same luck with sweep.

i'v managed to master getting the spline on the post many thanks to you but i cannot get a circle to extrude along it i type "sweep" at the command line but nothing happens i have also copied the spline and tried to extrude without any luck so far

many thanks sceejays

I don't think it's SWEEP is available in 2004. From a quick interet search I found a site which might be of use to you, particulary...

Yes you can make spring and threads in AutoCAD 2004 using thread.lsp & helix.lsp files...

To give credit, the site I found this at was:

http://www.dailyautocad.com/autocad-2007/advanced-solid-modeling-in-autocad-2007-helix-and-sweep/

Is this what you're after?

I couldn't find an entity that would extrude along a path, I tried many different ones, I probably wasn't doing something right I tried circles and cylinders from all angles. I'm a 3d noob though..

i'v managed to master getting the spline on the post many thanks to you but i cannot get a circle to extrude along it i type "sweep" at the command line but nothing happens i have also copied the spline and tried to extrude without any luck so far

 

many thanks sceejays

Use Extrude>Path in 2004.

Draw the SPLINE along the top of the posts.

[ATTACH]3517[/ATTACH]

Draw the CIRCLE at the end of the SPLINE.

[ATTACH]3518[/ATTACH]

_EXTRUDE "Select objects to extrude" select the CIRCLE and hit ENTER.

Specify height of extrusion or [Direction/Path/Taper angle]: P (for Path)

Select extrusion path or [Taper angle]: Select the SPLINE

[ATTACH]3519[/ATTACH]

You made it sound so easy... I'm an idiot, I got it now... I was hitting the extrude faces Icon in the solid editing toolbar, not the "extrude" in the modeling toolbar, same Icon, it worked perfectly when I typed in the command... hope sceejays got it ....

You made it sound so easy... I'm an idiot, I got it now... I was hitting the extrude faces Icon in the solid editing toolbar, not the "extrude" in the modeling toolbar, same Icon, it worked perfectly when I typed in the command... hope sceejays got it ....

Common mistake, I have to watch myself as I have both toolbars docked next to each other.

AutoCAD 2004 will not SWEEP and will not extrude along a spline.

Create a 3DPOLYline -most convenient using a spiral lisp or an Excel sheet- and extrude a circle along that path.

AutoCAD 2004 will not SWEEP and will not extrude along a spline.

Create a 3DPOLYline -most convenient using a spiral lisp or an Excel sheet- and extrude a circle along that path.

I can extrude along a spline in 2000i, it is a little tricky getting the circle lined up, though. Could try using the Spline-to-pline.lsp.

hi thanks for youe replies i have messed about with this project for hours i can put a spline to 3 no rails at a time and extrude thats all it will let me do if i try and do them all at once or try to extrude to 4 it won't let me but on the bright side at least i am having a certain amount of success

many thanks sceejays

AutoCAD, through 2004 anyway, will only accept a planar(flat) spline as a path for the Extrude command. Conceivably, with only 3 points, your splines are flat (that may not always be the case given off plane Tangent Vectors).

The Spline to Pline lisp with resultant pline as path is an option though it will probably produce a faceted rail.

Perhaps you could do the rail in segments. It is certainly more laborious, but doesn’t look to bad.

SpiralRail.dwg

I used to generate 3DPOLY paths. Making the segments "small enough" the extrusion will be "smooth enough". Generating automatically the path it is not a problem to set the segments size as it is desired.

Using the Spline-to-pline.lsp I was able to do this in 2000i.

Hi Guy This Method Is Too Long, U Guy Have Any Easy Method Thanks