topic Re: extruding a 3d polyline and spline combo and turning them into a solid in AutoCAD Forum

extruding a 3d polyline and spline combo and turning them into a solid

office6PUWT — Sun, 28 Feb 2021 20:26:18 GMT

Re the attached .dwg file I'm not sure if a spline and polyline can be combined into a single polyline that can then be extruded and turned into a soild. can anyone please show me how to turn this sketch into 120mm wide arched beam?

Re: extruding a 3d polyline and spline combo and turning them into a solid

Alfred.NESWADBA — Sun, 28 Feb 2021 20:46:16 GMT

Hi,

>> I'm not sure if a spline and polyline can be combined into a single polyline

Not to a polyline with just one command, but you can use command _JOIN to create a new Spline-object from your existing Spline+Polyline (a bit difficult with your geometry when you then try to close the open curve).

Alternative:

You can also try with command _SPLINEDIT to convert your Spline to a polyline, then run command _JOIN to join these 2 entities, make it closed an then extrude it. As shown here:

- alfred -

Re: extruding a 3d polyline and spline combo and turning them into a solid

leeminardi — Sun, 28 Feb 2021 21:00:21 GMT

Close the gap where the 3D polyline meets the spline.
Give the region command and select the 3dpolyline and the spline.
Extrude the region to create a 3D solid.

Re: extruding a 3d polyline and spline combo and turning them into a solid

office6PUWT — Mon, 01 Mar 2021 12:21:26 GMT

Thanks guys, really helpful.

I decided to rework the original spline and repeated the operation but was unable to create a region from my new 3d polyline using the same approach. I've checked for any gaps in the closed geometry and cannot see any. I'd be grateful if you could take a look at the this file aswell and help define what the problem is this time?

Re: extruding a 3d polyline and spline combo and turning them into a solid

Alfred.NESWADBA — Mon, 01 Mar 2021 13:06:43 GMT

Hi,

you can use command _BOUNDARY to create a standard Polyline based on your 3D-Polyline, this new Polyline can be extruded.

- alfred -

Re: extruding a 3d polyline and spline combo and turning them into a solid

office6PUWT — Mon, 01 Mar 2021 18:48:18 GMT

This has been a real headache, Boundary command worked for me but I had to redraw the geometry for a third time and now neither of the approaches you've shown me are working?? Could you have another look at it for me please. Attached saved as a 3d polyline from which I am unable to create a region or find any gaps.

all best

Luke

Re: extruding a 3d polyline and spline combo and turning them into a solid

Kent1Cooper — Mon, 01 Mar 2021 19:20:11 GMT

Does it need to be flat to make a Region? Looking straight down the X axis which is at the right end [rotated for viewing orientation here]:

Or, in plan view:

Re: extruding a 3d polyline and spline combo and turning them into a solid

Alfred.NESWADBA — Mon, 01 Mar 2021 19:24:52 GMT

Hi,

this time you have not drawn the objects in one plane, but to extrude a closed curve this curve has to be on one plane to get a 3D-Solid as result.

In this case you can help by setting the UCS to the plane you want to have the geometry projected to, then run command _FLATTEN and this should give you a geometry ready for running _EXTRUDE or _PRESSPULL.

- alfred -

Re: extruding a 3d polyline and spline combo and turning them into a solid

office6PUWT — Mon, 01 Mar 2021 19:52:09 GMT

thankyou so much excellent advice.

Re: extruding a 3d polyline and spline combo and turning them into a solid

office6PUWT — Mon, 01 Mar 2021 20:23:49 GMT

I spoke too soon, after closer inspection the flatten tool has altered the axis of the object despite the ucs being positioned as required? see attached image

Re: extruding a 3d polyline and spline combo and turning them into a solid

Alfred.NESWADBA — Mon, 01 Mar 2021 20:48:48 GMT

Hi,

First set the UCS to 3 of the endpoints of your contour.

Then use command _PLAN to this UCS.

Now run command _FLATTEN.

In worst case you need then to move the resulting geometry to the correct basepoint you'd like.

- alfred -

Re: extruding a 3d polyline and spline combo and turning them into a solid

office6PUWT — Tue, 02 Mar 2021 11:09:19 GMT

excellent thankyou