Filleting 3 line 3D sketch problem

It's impossible to have a 3D fillet feature, I think you can connect this kind of 2 space line segment by 3D spline. after draw the spline on any plane, you can add tangent relation to found a "3D fillet". You need to use other spline tools to fully define it, to make it looks like a fillet.

Got an idea. Workng on it. Be back in a day or two.

What I would do would be to turn the original lines into construction geometry, draw new lines and arcs in space disconnected from the original lines, and then once the tangent relations are working and the shape is approximately correct, drag the new lines/arcs onto the old construction lines.

Or, just draw the line connecting the endpoints, make 2 reference points at random locations, then key in coordinates to put them at the endpoints of the lines, then fillet the corners and drag the moved endpoints back to the reference points.

Another thing you could try would be to leave the original lines alone, draw the 3rd line, build sketch planes using the 2 endpoints of the 3rd line and the end point of an original line that the arc is to hook up to, and then you have planes for the arcs. Of course the new sketch plane function in 2006 is pretty fragile, and pretty likely to fail.

Or you could just say "screw it" and put a couple tangent splines in instead of arcs. You'll solve one set of problems and create another set.

There's not much in a 3D sketch that is what you call "fail safe", and because you're usually working with workarounds, nothing's really very efficient either.

good luck,

matt

Yes, if you don't care too much about the fillet radii.

Yes, but don't always count on the fillets haveing the same radius.

Yes, at least from a geometry standpoint it works except for two special cases one of which you probably will never want to try. However, SW gets quirky when implementing this.

Bullman wrote:

Yes, but......you can't always get the fillet radii you want.....it doesn't work when geometrically impossible.....and SW gets a bit quirky even when it is geometrically possible.

Paul,

Was that "turkey" or "Wild Turkey" that you were getting into? I see that you're responding, but what are you responding to?

Matt

I tried to respond when the post first came out. Nothing happened so posted again. Then today they all appeared at once after That 70s Tick responded. I was responding to Bullman's post.

Look at model "SkewFillet.SLDPRT" First sketch is two skew (non-intersecting) lines. Second sketch connects skew lines w/ fillets and line in middle.

Key elements: Sketch points coincident with original lines and middle line keep middle line intersecting the two skew lines so a fillet can be applied. Fillets were created by creating temporary construction lines collinear with original lines.

Similar to the construction I had. But.....just like mine it doesn't like having the first sketch changed. I doesn't want to solve. I used

2D planes in 3Dsketch to hold down the 3 point arcs. You can put all the geometry in one sketch. It still doesn't update very well.

Another stab. More complex, yet more robust, yet more complex. Pairs of dimensions in "Midline" sketch need to match to produce dependent fillet of equal length.

Suppose I should post the file location:

SkewFillet2.SLDPRT

One thing is apparent. The constraint solver in 3D Sketch doesn't work very well, even in 2006. I have used the second method when reverse engineering imported CAD geometry. Sticking with planes and 2D sketches is pretty robust.