Full Version: How can I extract and extrude an outer curve?

Show messages: All  1-9  10-13

Sure thing. Here's an example of an airfoil curve.

Attachments:
sampleRib.zip

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When I try with offset the inner curve isn't a closed curve. (The original is) I tried making an inset of the inner curve for fun and that one has a ton of segments where the points of the curve don't overlap so it creates a bunch of separate curve segments.

I tried extruding the outer curve then doing a boolean diff using the inner curve and that looked OK but my slicer tries to do some weird things with it when it sets up the print - some segments get detached moved into the middle. Not sure what's going on there.

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Hi Supagoat, well one problem is your curve isn't smooth, it's a polyline made up of 42 line segments.

An offset of that will work but it will be even more jagged. So it would be good to be working with a smooth curve rather than lots of little line segments.

It will also be problematic to do further work like extruding something like this because the fragmentation will inherit to that as well and you'll be working with an object made up of lots of little plane fragments rather than large smooth surface pieces.

re: offset of your polyline is not closed, it looks like that is related to this little dimpled area here:





It seems like that dimpled point is out of place. The change in direction there is making a shallow intersection that the offsetter isn't handling well, so you'll need to tune up that area with some manual trimming in order to make a closed curve:



Hope this helps!

- Michael

Image Attachments:
supagoat_offset1.jpg  supagoat_offset2.jpg  supagoat_offset3.jpg 

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OK yeah I retraced the airfoil with 'through point' freeform curves and then offset by .7mm inwards and was able to create a nice skin that will print well.

Thanks!

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Show messages: All  1-9  10-13