Compound Eliptical Arch

[henry]

At whit's end!!!! Trying to get a compound eliptical arch into Turbocad. I have a full size tracing of this arch. It measures 72 3/4" long x 17 5/16" at highest. If this was just an eliptical arch I would have no problem. I am working on cutting out a 3 1/2" trim for this arch. If anyone has any suggestions on how to get this tracing into the cad program I would greatly appreciate it...

Thanks
Henry

[davidallen]

you might try using the optical probe for the SB and mount the tracing on your table. that'd give you x,y coords that you'd need to translate to DXF or some other format that T-cad could read.

you could also modify the SB trace program to use manually move the router around the pattern and record discreet points.

[owp@comcast.net]

Henry

I have used two different methods to input the information. The first method is to take the tracing and draw a base line and a vertical center line. I then take the tracing and tape it to a sheet of plywood that is standing on edge. I then take a photo using a digital camera. I then inport the photo into my CAD program change to a new layer and trace one half of the photo. I use the base line and vertical line to make sure the photo is not rotated any. If it is I will rotate the photo to get the base line horizonal. The next step is to scale the drawing to the proper size. After scaling I then mirror the drawing to get the full elliptical.

The other method takes a little more time. I take a steel ruler and lay it across the base of the template. Then using a tee square I start at one end of the template and measure up to the line with the tee square. And then write down the cords. (example 0,0 .125,1.0625 .250,1.50) I then repeat this process moving the tee square 1/8" at a time. As I progress from the tight radius into the larger radius I will increase my horzonial step to 1/4" then 1". After doing this for 1/2 of the template I will then input these points into my cad program. I will then use a series of 3 point arcs to connect the points. After connecting the points I then mirror the half into a whole.

Hope this is some help. These can be a real pain to get them right. I have been manufacturing radius trim on a full time basis for over 8 years and still hate getting a drawing for and elliptical.

If you know the make of the window and would like to email me the information I may already have a CAD drawing of the template. If so I would be glad to email the dxf file to you.

[shuttle]

Does anyone know how to make 2D patterns from 3D (DXF,3DS...) objects?
The compound arch is a good example.

[rgengrave@aol.com]

Rob open the 3d file and rotate it to what you want and do a print screen and just trace it.

Ron V

[shuttle]

That's a good idea, but if I have a cone 3D model, how could I 'unwrap' it?

[rgengrave@aol.com]

Send me the file so I can see what it will take

Ron V

[owp]

Rob

I have uploaded a program to the incoming folder at shopbot ftp site the file name is cone13. The program will allow you to input the dimensions of a cone and will export a 2D and 3D dxf file of the cone. This program is freeware so there is no fees to keep it running.

Sam

[shuttle]

Sam,

Thanks very much, I'll have a look.

Rob

[shuttle]

Ron,

I am just interested in unwrapping odd 3D shapes in general, for my own know-how.
I have a model of a skirt, which I am trying to duplicate in chrome laminate. I must do it 1 poly at a time, they must then be laid flat and put into order, it is a slow process.