Troubles with splines

[DaveGadgeteer]

I'm trying to replace a decorative plate, to hide a hole.

I put a photo of the plate, scaled to the right size, on the sketch XZ plane, and proceded to trace the irregular curvy complicated outline.

Because I can't figure out how to make sharp corners between splines, I ended up using close spacing of spline points to work my way around the sharper corners, so there's an unreasonable number of points defining the spline outline.

However, I can select the interior and extrude it to form an acceptable starting base for the part, even excluding two holes for the screws.

Then I want to fillet the edge. Can't be done. The holes (defined by circles) fillet just fine, but no matter the fillet radius or other settings I always get an error message that the fillet can't be generated.

I'm surprised that the outline can be selected and the surface inside it pulled up, with no problem (OK, at first I had a stray piece of line doubled that had to be found and removed, but after that it worked), yet there's no fillet possible. I tried making a simple closed curve with splines, and that extruded and also filleted without problem.

So the trouble has to be the complexity of my traced spline.

There ought to be instructions somewhere for how to draw with splines, including how to create corner points and what the checkmarks mean, but I can't seem to find it for Fusion 360.

I'd upload my file, but I guess it's in the Cloud--not a file on my computer. Is there a way to upload it to show my problem? Export shows an Archive format, would that be the one to use?

A Noob

[DaveGadgeteer]

I did use a scan this time, and I did trace the tracing of it in Fusion--the initial trace in Illustrator was just to make the outline easier to follow in Fusion, because editing in Fusion is so tedious I don't ever want to make a mistake that needs to be corrected.

But now I have a very good outline in Fusion, using multiple splines a few of which are really just straight lines, and they appear to be connected (but how can I tell for sure?), but they don't result in a closed loop that I can extrude. I've tried using box select of the coincident endpoints and applying the Coincident constraint, but it's never available, which might mean they're already constrained, but I don't know. If I select the Coincident constraint then try to click two adjacent curve pieces, I can't select two, only one. Does that mean there's already coincidence applied there? I haven't tried this all the way around, because there's such a large number of joints to check and I don't know whether I'm doing it right, so might just be wasting time.

So the question is: when there's something wrong with the loop, how can I find the problem and fix it? Inventor has a process for that, but I haven't found one for Fusion--where is it?

Another question: how do you edit so easily, as shown in the video? You must have something different in your environment that makes the splines more amenable to editing. There must be some mode I get in. Sometimes the points won't just move, I have to right click, select move, select the point again, move it, etc. Very tedious.
Are there default mode settings set somewhere? And what could be causing my setup to insert horizontal/vertical constraints on the control handles even though I've not asked for that behavior as far as I can tell? Do you habitually hold Cmd down while editing (on Mac)?

Dave

[cekuhnen]

You sketch has many naked ends

zoom in and move along the sketch and you will see often here and there (I think5 or 6 times) that end points dont rest on each other.

[DaveGadgeteer]

OK, thanks! So the answer is one zooms way in and you can tell by looking. 

I was expecting the problem to be points on top of each other with an invisible constraint missing.

Meanwhile, using your previous info, I went the SVG route, and that is mostly wonderful! I took care by zooming in in Illustrator that the curve had no gaps, and put it into Fusion.

It was immediately extrudable. The result permits a .5mm bevel, so about the same as before. Also, I had to select every piece of the periphery individually--the system didn't know they were one curve.

But I did run into some bizarre issues: I wanted to move the SVG shape and then scale it, because the dimensions were too large and needed to be reduced by about 0.162

I was able to select the whole shape, or any individual point, but when I tried to Move the selection was lost and while the Move dialog was open, nothing could be selected. So pre-selecting didn't work, and post-selecting was impossible. This would be understandable in that maybe Move is not implemented, just as curve editing is not implemented. But I did something by accident that briefly made it work! However, my view wasn't convenient and when I stopped the Move to fix that, I was never able to get selecting to work within Move again. I tried everything I could think of, invoking Move in various ways, clicking with various combinations of modifier keys, etc., but I was never able to get Move to work.

So I used a different approach, and extruded a few mm first, then moved the resulting body and scaled that. That worked.

The rest of the process worked as one would expect. The remaining problem was one of the original holes was larger than the hole size I was aiming for, so the countersunk hole tool couldn't work without error until I filled the original hole in somewhat. It wasn't exactly round, apparently, so I couldn't easily just plug it, but had to select all 4 surface regions inside the hole and pull them inward to shrink it. After that I was able to finish the desired countersunk holes and am now printing it (after a precautionary repair pass through NetFabb).

I still think there's some mysterious thing wrong with my human interface settings--there must be some hidden controls I haven't found. There shouldn't be so many mode changes as I'm bumbling into. Anyway, I'll work through more tutorials and hope I figure out what I'm doing wrong.

Next I had intended to sculpt some decorations on the upper surface, but perhaps it's easier to do them separately and just glue pieces on. If I try within Fusion, I assume the method would be to create a form above but touching this base and hope there's a way to merge the form with the base so it becomes one object for printing.

Dave

[cekuhnen · Accepted solution]

Hey glad to see it works better now.

Here is btw a new video with Audio!!! explaining G0toG2 in Alias and Fusion and some tricks to get along with the way Fusion only offers spline tools.
https://drive.google.com/file/d/0Byzv_NlyKp_2dTdjaFpCVk1jMnc/view?usp=sharing

I hope this helps!

[cekuhnen]

Oh boy I made a silly mistake - G2 / smooth graphs in Fusion look pinched because well thats the way they are - same in Alias. To get automatically perfect smooth combs one needs G3. Here is a video explaining this (Alias Fusion)
https://drive.google.com/file/d/0Byzv_NlyKp_2TjdtdDAyUUR5dlU/view?usp=sharing

But Fusion being currently spline based only has some nice other tools CV curves do not have:
https://drive.google.com/file/d/0Byzv_NlyKp_2NWhIZDBtRm0tR0k/view?usp=sharing

[DaveGadgeteer]

Thank you!

These videos were tremendously helpful. I'll be viewing them multiple times.

I'm a bit puzzled why they don't play for me in Safari. They show a black screen and seem to be loading forever but eventually fail; however, I can download them very rapidly, and then they play fine in QuickTime Player. So there must be some deficiency in the Safari setup. They do play in Chrome with no problem.

It was very helpful for me to see your working environment and way of working. And I see that you, too, get automatic horizontal constraints on the handles that you didn't intend and that need to be manually deleted.

Your motivation is a bit different from mine for this project, where I just want an edge that follows a reasonable path and don't care much about smoothness, but for other projects I too will want smooth curves. I see G0 as position only, G1 as slope or tangent, G2 as smoothness or curvature, G3 as rate of change of curvature, etc. So much of what you are doing in Fusion to make things smooth is manually adjusting things to get the curvature rate of change to be smooth across a join, manually tweaking to get the effect a G3 join would have if it existed in Fusion. 

Just now I figured out how to make the spline tool show up in the toolbar, which I knew was possible because of seeing your setup. I probably missed a bunch of things from the tutorials so I should do even the basic ones again.

It never would have occurred to me to dimension the handles! Neat trick. I bet that also will allow forcing multiple sets of them to have the same or mathematically related values, since Fusion seems to have the same parameter model as Inventor, so one could enter =d23 as a value for example.

Alias looks really neat. I don't know whether to start learning that also... if it were easy to move designs back and forth between Alias and Fusion it probably would be worth it.

But there are so many things I need to learn. Soon I need to get comfortable with Eagle. I wish everything used a common interface behavior, to the extent possible! At least the Mac has made a lot of the basic stuff consistent, which is a big help that we take for granted now. (Yesterday I improved the UI by a lot--I've been using a Logitech optical mouse because of the convenience of the right click and scroll wheel, but every time I went to do something that made me grip it a little tight I'd trip the thumb button, causing a major delay as the Mac would switch to a display showing the various Spaces and I'd have to work to get back. I finally found a Logitech driver that let me disable the thumb button. At first it seemed not to work, no Logitech devices found, but after a while I happened to look again and there was the mouse. It really complicates bumbling around when you don't know you need to wait a while for things to change!) 

I also added a SpaceMouse last week, which is extremely helpful when playing with 3D designs. With that I can almost do with the trackpad and forget the Logitech mouse, but they all seem to live together happily (as long as you don't bump one accidentally!--I'm not working at a desk, just a laptop on a tray).

Anyway, thank you so much for the explanations, and for the incredible amount of time you've invested!

Dave