Gateway to the West Arch

[Anonymous]

I am creating an arch similar to the Gateway to the West Arch in St. Louis, Missouri, only not quite on the grand scale the gateway is.
How would I do this in archicad?
I have tried a few features only to stopped at dead ends so far.

Thanks

Timothy Green
Instructor
Howard College
Big Spring, TX

[Steve Jepson]

Thanks for posting that technique Matthew.
I like it! I can use it for several things I have been doing the hard way.

[Ralph Wessel]

Peter wrote:
I notice that your arch has a rectangular cross section.
Can Objective make a tapering equilateral triangle cross section
like the gateway arch ?

Not directly, although you can SEO one OBJECTiVE profile from another to achieve that affect. Refer to the attached image. Took less than 1 minute to make.

[Ralph Wessel]

Peter wrote:
Can Objective make a tapering equilateral triangle cross section
like the gateway arch ?

Sorry - triangular section this time

[Anonymous]

Hello Ralph,
Thank you. That is quite impressive.
Peter Devlin

[Anonymous]

As usual, objective rules!

[Anonymous]

Dang,

I guess I didn't know ArchiCAD as well as I thought.

Thanks for all the help ya'll

Timothy Green
Howard College
Instructor
Architectural Drafting
Big Spring, TX

[Anonymous]

Hello Tim,
If you don't want to use an add-on but want to model
an arch like the gateway arch entirely within Archicad,
I would suggest the method outlined by David Collins
except constructing a catenary curve for the entrados
or extrados of the arch rather than tracing as David
suggested, though you could use the image to get
the proportions of the catenary . Your topic is an
intriguing problem in drafting and modeling.
Peter Devlin

[Anonymous]

Try this. It should be fairly close to what you want.

Please note that it's still a *little* buggy when you start adjusting the sizes of things, and you may find it disappears completely! This is because the tube used to form the section is right on the limit before it self-intersects. If anyone wants to see if they can make it work better, please go ahead!

It works by throwing out some tubes in a parabola, then it places a similar version slightly lower with a negative shaped section then cuts one away from the other.

See the GDL Cookbook 3 p165-166 for the various codes for arches.

Hope it helps.

[Anonymous]

Here's a picture -