Can't Figure This Out: Different Results from Same Operation

[oi3WS5F]

If anybody has an idea on this, I'd appreciate feedback:

First, I draw everything in AutoCAD and then XRef into F360 for modeling, usually with little trouble. On this particular project, I have two drawings made from the same file.  One comes in at 0,0,0 but the other at Y 12.0", which isn't a problem as I just move it to the right spot.  Yes, both drawings have the same units, origin, etc.  I'm only mentioning it if it pertains to the real problem:

In the top model, Brace 1, the same sketch is imported on two different planes, and then the ends of the spline curves are dropped down by just grabbing the end and moving by any number of ways, which all work.  If you take the model and look at it from the top, the curves aren't exact but that's OK as they are CNC'd and then sanded by hand afterwards - this is just doing the grunt work.

On the lower Brace 2, the right point, furthest from the origin, also moves as expected, but the left point gives me terrible results:  the spline curve rotates in odd ways and lands in an odd location.

Two days later and redrawing/reimporting several times, it doesn't work.  I've pulled this same trick off many times with no problems...but...

[Joshua.Aigen]

Hi @oi3WS5F, I'm having a hard time understanding what you are trying to do, but I did notice a few things. 

1. The spline imported in Brace2 has 2 spots that the spline is broken, this seems like an artifact of AutoCAD?
2. When trying to look into the trace toolpath you used I received an error about missing refences.

I hope you were able to find the issue, your workflow is different than most users I've seen. If I can give some advice it's to look into constraints, if I were you I'd be worried that things moved or are different too. That's because without any dimensions or constraints the splines are kind of just floating around. One last question is I'm trying to understand the reason for using AutoCAD, was the original design done there?

[oi3WS5F]

Hi Joshua

Thanks for your reply!   In response:

1. I've used AutoCAD for 30 years and don't have to think very hard re:
the command structure.  On the other hand I find F360 to be VERY
cumbersome and unintuitive.

2. One of those being the constraints, which don't exist in AutoCAD
(Architecture).  I understand in concept, but when importing via DXF
they are very difficult to deal with, and frequently "locked".  My F360
limitations I'm sure...

3. Which does make my workflow backwards from most...  sorry about
that.  This is small but critical part in a much larger file, which
relates to many other similar files, and I would beat my head against
the wall if I tried to do the whole thing in F360 as it's more of an
architectural project than parts manufacturing.

4. When trying to move just one end of the spline, per my headache, it
was modifying the whole spline curve rather than just the end.  I find
it especially odd that one of the curve is modified as expected, the
other... not.  So the splines were intentionally broken to try to get
around that... but not ideal or successful.

5. The XREF importing into Y 12 seems inconsistent and unsolvable, but
there are generally no coincidences in this kind of situation, so it may
be related.

6. So my workaround was to draw a new 3d spline curve in F360 over the
old AutoCAD reference points.  It doesn't lay on there perfectly, unless
I add more spline points which would be mathematically real difficult
floating around in 3d, but I'll have to live with it unless I can
discover the source issue.  I suppose in the future I could develop a 3d
model in AutoCAD and see if that imports correctly...  but this is just
a hobby project so there's only so much effort appropriate to the end goal.

It may just be that as my workflow is backwards, and not really as F360
was designed, I've simply hit some limits...  but fortunately I've been
able to do 99% of what I need.  It's an interesting program for sure,
just not perfectly in sync with each other.

thanks!

Kevin

[HughesTooling]

@oi3WS5F  Not really sure about what you are trying to achieve but is it more predictable if you fix the point at the other end of the spline before moving the other end?

[Joshua.Aigen]

Hi Kevin, Thanks for the reply.

I think it's great that your using the software in a different way. It is not easy using AutoCAD or Fusion. I like your idea of bringing a 3d AutoCAD file into Fusion, though I haven't done that. If you were able to bring in to Fusion the correct spline I would recommend using a surface to split the extrusion and I have included a file with an example. A surface can be created from a line or a spline. This could allow you to create one profile on a XY plane to extrude up and then a spline on the XZ or YZ plane to create a surface across the extrusion. Another option could be instead of dragging the spline into position try rotating it with the move/copy tool as in the picture.

I hope this helps, and good luck.