normally when I make a wire it's a 3D spline connected to two 3D lines (stubs), and that works pretty good, but I'm trying to transition from some twisted wires, and that doesn't look very good. Is there a technique to make smooth transitions from a helix to a spline?
Just have your spline connect directly to the end of the helix and set them to be tangent.
That worked surprising well. I was surprised because when I've tried that before it looked like the spline put itself tangent on the side of the existing wire, not in the middle, but it worked. Unfortunately, I had an unexpected surprise: The end of the spline terminated off to the side, and not in the middle.
I am assuming you are using a sweep for the wire? The result you show makes it seem like the sweep profile is not centered on the beginning of the path. Instead it looks like the path endpoint lies on the profile circle instead of in the middle of it.
I'm not sure what to do. I don't think a straight stub will do it. I would like to do a tangent to the end face of the helix portion and have it centered on the face, but I haven't been successful yet. I was playing around and I was able to center the spline on the end face of the helix and manually eyeball it with fair results. Maybe it's one of those things where there's no good answer.
Wild guess here but I suspect your sweeps are not normal to the trajectory which is causing issues with the transition.
Be sure to define a plane normal to the trajectory to sketch your wire's circle.
Instead of sweeping the helix portion of the wire first and then trying to add the spline you should combine the helix and the spline first and then sweep the entire thing. I'm not sure if that's what you are doing. You could combine them by converting the helix into a 3D sketch and then drawing the spline, or you could draw the spline by itself in a 3D sketch and then create a composite curve. Also as Tom mentioned it will probably look better if your profile plane is normal to the start of the path. See my Example.
I converted the helix to a 3D sketch and added the splines to it with tangent relations. Then I did a "fit spline", which seemed to make it all one entity for the sweep. I repeated this for all the wires since they are all different part numbers (actually this is just a test piece). A little tweaking on the spline handles made it look a little better. The twists look more like coils, but that's an easy fix when I do it "for real". Since you mentioned it first you get the kudos. Thanks!
Smooooth!
Hello Andrew,
I always convert the spline and the helix into a separate 3dsketch and the do a fit spline over the 2 converted enities
That way I always get a smooth transition
with kind regards
Francesco
Try this boundary blend option:
That an interesting idea. I've never used Boundary Blend. I'll have to learn about that. Thanks for the tip!
I was having trouble with twists in the spline where it required curvature continuity to solve.
I always model them square first to see what is going on.
When I looped this one it had a 180 degree twist making for an ugly transition with the zebra stripes.
That is where the boundary blend made the transition easier to deal with. Not as many hoops to jump through.
Instead of sweeping the helix portion of the wire first and then trying to add the spline you should combine the helix and the spline first and then sweep the entire thing. I'm not sure if that's what you are doing. You could combine them by converting the helix into a 3D sketch and then drawing the spline, or you could draw the spline by itself in a 3D sketch and then create a composite curve. Also as Tom mentioned it will probably look better if your profile plane is normal to the start of the path. See my Example.