Error or Artifact?

[Anonymous]

I'm currently navigating the wonderful world of lofts, and being perpetually new at this I'm not sure what to do with an all-to-frequent error message that the rails don't intersect the profiles on my 3D sketch. I don't know what to do to find out exactly where the disconnect is, and this has led me on many a not-so-merry chase in the last week or so.

I have tried to use approaches such as magnifying the intersection to the maximum to see if a disconnect is visually obvious. In doing so, I have found on many occasions that a line I snapped to an arc (for example) goes past the arc, which makes me think, "AHA! There you are you little rascal!!" But the overshoot can't be trimmed, and if I try to place a point on what appears to be the intersection, it won't go anywhere except at the top of the overshot line.

I'm beginning to think that this isn't really an error, but a display artifact. Is this a known issue? Just need a little clarification on this so I can go sniffing around somewhere else.

[Anonymous]

Yes, I really like Fusion CAM, possibly better than Fusion Design itself, and I mean that as a compliment since Fusion 360 is, to me, anyway, one amazing piece of software.

When I started this project, I was as green as green could be, and since I knew that a steep learning curve lay ahead, I proceeded on the theory that I would bang away at Fusion until I could draw and manufacture the first step of producing my model in real life. My idea was that whatever I couldn't get my CNC machine to do, I could always finish by hand.

Then I met you guys and got my ears boxed and my eyes opened. I found that I could get farther in Fusion than I thought, and so I would have less to do by hand afterward. But you see the trap that awaits me. I will keep improving my design skills and refining my model, but I will never get anything to the CNC machine! 😐 But I guess if this is a problem, it's a good one to have.

I am really anticipating whatever ideas you and the others come up with. And just in case you find the solution, I am already preparing new dilemmas with which to bother you!

[Anonymous]

I am at home self-quarantining, social distancing, and sometimes hiding under the bed. I hope all is well wherever you are.

Of course, when I'm not dreading the virus, I'm working on my violin drawing Attached is my latest attempt to loft the arch the Trippy way. I think I'm making progress, but I can only get a partial loft of the inner profiles. Obviously, I am either doing something wrong, or I'm leaving something out. Or both, probably.

A question also about those helper extrusions. Is it possible later on to make them back into lines again? Just not sure of how those surfaces will react when I need to extrude or thicken the model. Also, I didn't use a helper plane on the flat portion of the sketch because it is already on a horizontal plane of origin.

[TrippyLighting]

This lofts just fine and the design contains everything needed for the loft!

Definitely good progress!

A word on the helper surfaces. The helper surfaces only make a difference if you change the appropriate conditions for the profile and /or rails to G1 or G2. IN this case, G1 toward the spine profile. That will only be possible if you select an edge of a surface. Tangency and curvature are conditions that only make sense across one or more surfaces.

That is also the reason you don't really need a flat helper rail for the perimeter.

[Anonymous]

After I got your reply I tried the loft again and it worked perfectly. I've been watching the screencast you made for the guitar maker and saw the trouble you had when you could not move a single point under a spline handle. Then all of a sudden, it could be moved. I think that Fusion must be crunching numbers in the background and takes a long time to catch up. I also saw that you had a green (fixed) line that I didn't think you created. I have had this happen sometimes when a line or a point will become fixed even though I didn't work on it. This must be a bug. It can be annoying.

My loft is not quite as smooth as the one we got using arcs and five rails. I will play around with it to see if I can do better, but it's actually not so bad that I can't clean it up at the end by hand. I think to make it really smooth I would need to deal with lofting into the corner points. Since these drawings will be used to generate CNC G-code, and since no router bit can make such a sharp point, I might be able to do some creative rounding.

Thank you for the screencast showing how to remove all the helper surfaces, etc. Very helpful!

[oscardel.barcobarrantesAPJNL]

GREAT!