topic Re: Fit Point Spline Question in Fusion Design, Validate & Document Forum

Fit Point Spline Question

t_smith5 — Sun, 26 Feb 2023 19:11:57 GMT

I suspect I'll be asking a LOT of questions... 😁

I've recently started learning Fusion 360, so I'm encountering a lot of problems and confusion.

My first question is:

When using the Fit Point Spline, is there a way of making some of the lines angled/straight? When sketching over a reference, some parts might go from rounded to straight and vice versa. Is this possible?

Thanks

Re: Fit Point Spline Question

davebYYPCU — Sun, 26 Feb 2023 19:27:51 GMT

Splines by definition are curved.

Draw the straight lines first.

Connect Tangent arcs to the end of the lines,

Splines as last resort.

Might help....

Re: Fit Point Spline Question

t_smith5 — Sun, 26 Feb 2023 19:44:26 GMT

Okay, thanks. Is that what's used to join up two separate splines in general?

Re: Fit Point Spline Question

davebYYPCU — Sun, 26 Feb 2023 20:26:31 GMT

No idea of the reference material you are tracing, but you can’t make a straight spline with more than 2 points.

A 2 point spline should be a line instead.

Might help....

Re: Fit Point Spline Question

t_smith5 — Sun, 26 Feb 2023 20:41:16 GMT

Okay, I'll bear that in mind the next time I use the tool and see if I can get it working right.

Re: Fit Point Spline Question

g-andresen — Sun, 26 Feb 2023 21:25:00 GMT

Hi,

If you do this, please note that the principle of "less is more" applies to splines.
This means: As many control points as necessary, but as few as possible.

Günther

Re: Fit Point Spline Question

etfrench — Mon, 27 Feb 2023 06:32:46 GMT

You can extrude the shape, then convert it to a mesh. You can then use Create Mesh Section Sketch. Edit that sketch and use the Fit Curves to Mesh Section tool. You can use arcs, splines, and straight lines with the tool.

Re: Fit Point Spline Question

t_smith5 — Mon, 27 Feb 2023 12:19:04 GMT

You mean extrude the splines...? How do you do that?

Re: Fit Point Spline Question

t_smith5 — Mon, 27 Feb 2023 12:26:46 GMT

I managed to convert the splines into a Patch, which has given me a new plane, but I can't seem to figure out how to extrude it.

I could do with a strip running around for a mouth region.

Re: Fit Point Spline Question

TheCADWhisperer — Mon, 27 Feb 2023 12:28:22 GMT

@t_smith5 wrote:

I suspect I'll be asking a LOT of questions... 😁

@t_smith5

I recommend that at the beginning you Attach your *.f3d file with every question (done as best you can) and after each and every sketch/feature. (Not mere pretty pictures.)

The experts here will diagnose and make suggestions for best practices to avoid developing bad techniques.

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

Re: Fit Point Spline Question

t_smith5 — Mon, 27 Feb 2023 12:28:20 GMT

Sure thing. No problem. 🙂

Re: Fit Point Spline Question

t_smith5 — Mon, 27 Feb 2023 12:30:32 GMT

Here's my attached file. I'm not sure if the reference image I have set up will carry over to someone else's PC...

Re: Fit Point Spline Question

TheCADWhisperer — Mon, 27 Feb 2023 12:39:06 GMT

I would have moved the Canvas to position over the Origin.

I would have fully defined the Base sketch (blue lines and white dots should keep you awake at night).

Where are your dimensions?

Why is the axis of rotation not at the center of the circle?

Re: Fit Point Spline Question

t_smith5 — Mon, 27 Feb 2023 12:44:20 GMT

I'm not quite sure how you'd move the Canvas to position over the Origin. 😅 Also, is it possible to move that origin point to a mesh/body? I know you can snap a body to it, as well as move the Axis point where you roughly want, but can you move the Origin itself where you want?

As to the dimensions of everything, I'm afraid I don't know. I only know the size of the mech itself, which is around 609.6cm. I added a measuring line into the scene for that. Everything else is a guess at this point. I'm just checking if the various parts are matching up with the reference.

"Why is the axis of rotation not at the center of the circle?"

I have absolutely no idea. I didn't even realise it wasn't. I don't know how to fix that. 😅

Re: Fit Point Spline Question

TheCADWhisperer — Mon, 27 Feb 2023 12:53:56 GMT

Note that your Measurement line is not fully defined.

Missing a Vertical constraint.

Re: Fit Point Spline Question

TheCADWhisperer — Mon, 27 Feb 2023 12:59:48 GMT

@t_smith5

The Canvas can be edited to move to the Origin.

What do you notice about my sketch (see attached file)?

Re: Fit Point Spline Question

t_smith5 — Mon, 27 Feb 2023 13:03:10 GMT

I'm afraid you've completely lost me there.

Re: Fit Point Spline Question

t_smith5 — Mon, 27 Feb 2023 13:12:21 GMT

That... the sketch is perfectly around the reference image...? That your sketch is 375cm...?

I've gone to Edit Sketch for the Canvas and just clicked the dot of the Origin, which has snapped it to the centre, but it's in a different position to yours. I'm guessing you dragged it along yours...?

I'm still not sure what you mean regarding that Measurement line not being defined. 😖

Re: Fit Point Spline Question

t_smith5 — Mon, 27 Feb 2023 13:19:57 GMT

I've deleted the old measurement line and made a new one, but I've no idea if I've done it right or what I didn't do before. As far as I'm aware, I did the exact same thing as before. I've attached the new scene:

Re: Fit Point Spline Question

t_smith5 — Mon, 27 Feb 2023 13:37:39 GMT

Even as a Sketch I'm not able to scale it down...? 😕