Sheet metal cone ?

wayne_sauder

Is there a way to convert a lofted cone to sheet metal? I know Onshape said they do not support rolled sheet metal at this point. I tried breaking it into many sides by sketching two equal sided polygons and lofting between them, and then step bending that, but that does not work either. Just wondering if there is a way to do something like this.  

NeilCooke

@wayne_sauder search "square to round" in the public docs for an example of a cone created on a press brake. 

Jake_Rosenfeld

You may have more luck extruding just one polygon with a draft rather than lofting between two polygon profiles.

https://www.youtube.com/watch?v=4v8DXdcAQJQ

Jake_Rosenfeld

Hey Wayne,

If you want to do it your original way, I found a pretty easy way to do it.  I think the issue with your original attempt might have been that your polygons didn't line up slightly, and this made the faces of your lofted poly-cone non-planar.

https://cad.onshape.com/documents/0c17532c1f331e54f363eddf/w/6ff95ff52fa1b9b315304fcb/e/6a42f3b05241421b03700fa7

So what I did was set up the original (bottom) polygon on one of the default planes.  Then, I set up the top plane for the cone, started my second sketch, and 'use'd the other sketch to get the original sketch onto this sketch plane (https://cad.onshape.com/help/Content/sketch-tools-use.htm).  Now that I had the original sketch I used the sketch offset tool to make a smaller version of the original polygon (https://cad.onshape.com/help/Content/sketch-tools-offset.htm). By using 'use' and 'offset' I ensure that the geometries of the bottom and top polygons are perfectly matching.  I then lofted and used the normal Start Sheet Metal -> convert method to create the sheet metal.

There are lots of workflows for everything! Hope this one is right for you.

Rolled features are definitely on our radar.  Feel free to vote on this improvement request if you would like to help us sort our priorities and be notified when the feature is complete: https://forum.onshape.com/discussion/5815/sheet-metal-cylinder-flattening

NeilCooke

@wayne_sauder search "square to round" in the public docs for an example of a cone created on a press brake. 

Jake_Rosenfeld

You may have more luck extruding just one polygon with a draft rather than lofting between two polygon profiles.

https://www.youtube.com/watch?v=4v8DXdcAQJQ

Tony_C_

Gotta try that.....I still do cones the old fashion way in 2D.....

wayne_sauder

I understand both methods, For what i was trying to do using draft was the better method. It requires more calculations, because a lot of times i am given the top and bottom of a cone, and it would be easier to draw those and loft, although some math or a few simple sketches to find the angle is not hard either.  It would be nice to have a option for rolled sheet metal.

Jake_Rosenfeld

Hey Wayne,

If you want to do it your original way, I found a pretty easy way to do it.  I think the issue with your original attempt might have been that your polygons didn't line up slightly, and this made the faces of your lofted poly-cone non-planar.

https://cad.onshape.com/documents/0c17532c1f331e54f363eddf/w/6ff95ff52fa1b9b315304fcb/e/6a42f3b05241421b03700fa7

So what I did was set up the original (bottom) polygon on one of the default planes.  Then, I set up the top plane for the cone, started my second sketch, and 'use'd the other sketch to get the original sketch onto this sketch plane (https://cad.onshape.com/help/Content/sketch-tools-use.htm).  Now that I had the original sketch I used the sketch offset tool to make a smaller version of the original polygon (https://cad.onshape.com/help/Content/sketch-tools-offset.htm). By using 'use' and 'offset' I ensure that the geometries of the bottom and top polygons are perfectly matching.  I then lofted and used the normal Start Sheet Metal -> convert method to create the sheet metal.

There are lots of workflows for everything! Hope this one is right for you.

Rolled features are definitely on our radar.  Feel free to vote on this improvement request if you would like to help us sort our priorities and be notified when the feature is complete: https://forum.onshape.com/discussion/5815/sheet-metal-cylinder-flattening

wayne_sauder

Thanks Jake, that workflow works perfectly for what i want to do. Evidently my original problem was as you mentioned my polygons did not line up perfectly.  

Jake_Rosenfeld

Glad I could help Wayne.