topic Re: Cannot create a mirror in an sketch drown in an inclined plane. in Fusion Design, Validate & Document Forum

Cannot create a mirror in an sketch drown in an inclined plane.

richrfl — Tue, 26 Jul 2022 13:30:11 GMT

It happens that when I edit the sketch it appears shifted from the center of coordinates. If I try a walk around by using references to trace the line, that line is off the plane (cannot understand why I can draw a plane off my sketch plane anyways). Also, how can I see my sketch in a normal view to its plane? Sorry for these questions but this is my second week using Fusion.All sketches centeredSketch off center on EditSketch not center on Edit 2Line off my sketch plane???

Re: Cannot create a mirror in an sketch drown in an inclined plane.

jeff_strater — Tue, 26 Jul 2022 14:02:49 GMT

Most likely, you have "3D sketch" enabled in your sketches. Fusion supports sketch elements that are not on the sketch plane (there is no separate 3D sketch type in Fusion). So, it is more than likely that some elements of your sketch landed elsewhere. You can change the active plane during curve creation, and you can snap to model geometry. If you want pure 2D sketches, disable 3D curve sketching:

and, yes, Sketch Mirror does not work on items which are not on the sketch plane

Re: Cannot create a mirror in an sketch drown in an inclined plane.

wmhazzard — Tue, 26 Jul 2022 14:45:09 GMT

You also have way too many points on your splines, they will create bad geometry. For your oval shape, you only need 4 points with a fit point spline to create your shape.

Betreff: Cannot create a mirror in an sketch drown in an inclined plane.

g-andresen — Tue, 26 Jul 2022 14:49:56 GMT

Hi,

When editing splines, it can happen that control points are unintentionally moved out of the plane.
By right-clicking on the curve, the option "move to sketch plane" appears in the menu. This way you get all the "refugees" back onto one plane.

günther

Re: Cannot create a mirror in an sketch drown in an inclined plane.

richrfl — Wed, 27 Jul 2022 12:16:22 GMT

Well, I think that either I don't know how to get this Preferences window, or my SW (personal V2.0.1) does not have that feature as such. However, the Sketch Palette show 3D sketch not checked.

Re: Cannot create a mirror in an sketch drown in an inclined plane.

richrfl — Wed, 27 Jul 2022 12:25:55 GMT

Thank you for your response, I never tried the "fit point spline" and I will see what I can do with it. However, I don't think the number of points is an issue, of the basic loft would be very ugly. The real issue here is the almost impossibility to make points coincident with planes (orthogonal or otherwise).

Re: Cannot create a mirror in an sketch drown in an inclined plane.

TheCADWhisperer — Wed, 27 Jul 2022 12:29:05 GMT

@richrfl wrote:
Well, I think that either I don't know how to get this Preferences window.

However, the Sketch Palette show 3D sketch not checked.

Your screenshot shows that 3D Sketch is checkmarked?

There are a plethora of issues here - it is hard to decide where to start.

Form in Timeline?

Unresolved issues highlighted in Timeline?

Unreasonably complex spline curves?

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

And explain your Design Intent.

Is there something similar that already exists in the real world that you could point to as reference for your Design Intent?

Betreff: Cannot create a mirror in an sketch drown in an inclined plane.

richrfl — Wed, 27 Jul 2022 12:30:16 GMT

Ok, that may solve the issue with the line out of the plane, and that may solve some issues I am having using those splines as guides for the loft, because they may not be in the sketch plane. Also, if I can bring the straight line back to the plane, I may have to walk around to do a symmetry operation and have both issues solved. Will check that out and come back with what I got.

Re: Cannot create a mirror in an sketch drown in an inclined plane.

TheCADWhisperer — Wed, 27 Jul 2022 12:33:09 GMT

@richrfl wrote:
However, I don't think the number of points is an issue,

Number of points is just one of many many issues.

Attach your *.f3d file here and end all doubt.

Re: Cannot create a mirror in an sketch drown in an inclined plane.

davebYYPCU — Wed, 27 Jul 2022 12:55:35 GMT

Too many spline points.

use 2d sketches.

use Project > Intersect on the profiles when creating the Rail sketch, hide the profile sketches and connect rails to your purple points.

with experience you won’t need rails with surface tangent / direction controls.

Might help....

Re: Cannot create a mirror in an sketch drown in an inclined plane.

richrfl — Wed, 27 Jul 2022 15:39:16 GMT

Oh, boy I should pay better attention. Sorry.

Re: Cannot create a mirror in an sketch drown in an inclined plane.

richrfl — Wed, 27 Jul 2022 15:44:18 GMT

The number of points has a limitation? Anyways I am sending you the file attached. One issue I had was to have the spline in 3D. Symmetry is still an issue but using quasi-symmetrical shapes and slicing/mirroring gives me the walkaround.

Re: Cannot create a mirror in an sketch drown in an inclined plane.

richrfl — Wed, 27 Jul 2022 15:48:35 GMT

Yes, experience is what I lack a lot on this SW. I think I was able to produce a reasonable result, but I will check your suggestions and see if I can get something even better.
Thank you for your leads.

Re: Cannot create a mirror in an sketch drown in an inclined plane.

richrfl — Wed, 27 Jul 2022 15:55:29 GMT

I found the preferences windows. Thank you. The check box is clean.

Re: Cannot create a mirror in an sketch drown in an inclined plane.

TheCADWhisperer — Wed, 27 Jul 2022 15:58:49 GMT

Let's start with your first sketch - Sketch3.

Right click and select Edit Sketch.

Right click on the spline(s) and select

Toggle Curvature Display.

Re: Cannot create a mirror in an sketch drown in an inclined plane.

TheCADWhisperer — Wed, 27 Jul 2022 16:33:32 GMT

How will you manufacture this?

What is your manufacturing tolerance?

Is aerodynamic drag important to your design?

Open the Attached file.

Turn on visibility of Sketch3.

What do you observe?

Re: Cannot create a mirror in an sketch drown in an inclined plane.

richrfl — Wed, 27 Jul 2022 21:12:59 GMT

I will 3D print this. About tolerance, it is expected to be 0.5% all around. The drag, would not be affected too much with a slight size difference.
Now about sketch 3, what I see is that the two-point spline cannot follow the basic shape of the of the bulkhead. However, the differences would be within the tolerance.
The two-point splines solved the issues of the guide nicely. Attached is what I got so far.
I will make a new design following our suggestions and see what I get. The process is much easier your way, and the results may be not too different. BTW, I still do not get why the number of points is an issue, except, eventually, if it affects file size or computer performance, neither of which I found.

Re: Cannot create a mirror in an sketch drown in an inclined plane.

davebYYPCU — Wed, 27 Jul 2022 21:25:02 GMT

BTW, I still do not get why the number of points is an issue,

because you are not using Shell or Thicken yet.

Might help....

Re: Cannot create a mirror in an sketch drown in an inclined plane.

TheCADWhisperer — Thu, 28 Jul 2022 12:27:05 GMT

@richrfl wrote:
Now about sketch 3, what I see is that the two-point spline cannot follow the basic shape of the of the bulkhead.

However, the differences would be within the tolerance.

Where do you see this?

What scientific/mathematical technique are you using to see this?

Do you have the original design specifications? Did the original designer use specific equation curves that can be replicated by anyone? (The scientific method.)

Let's go back to first principles...

Your original canvas is a mere image.

Is that image perfect?

Is it symmetrical from side-to-side?

Did you merely "eyeball" trace over a less than perfect image?

I spent only limited time on my curves to try to illustrate a (limited) point (pun intended). If I spent more time I might get closer replication - but replication of what? I don't have access to the original design specifications, only a questionable image.

In fact - if this were my design I would attempt to reproduce (within any reasonable manufacturing tolerance) with ONLY lines and tangent arcs (no splines). Keep the geometry to that which I can actually measure (Splines and Lofts reach into the realm of art - where I have no manufacturing experience and am cautious about entering).

Re: Cannot create a mirror in an sketch drown in an inclined plane.

wmhazzard — Thu, 28 Jul 2022 12:46:26 GMT

"I still do not get why the number of points is an issue, except, eventually, if it affects file size or computer performance, neither of which I found."

When you have too many points, you get bad geometry.

This is a spline with too many points with curvature analysis on.

This is a good spline.

If you feel like you just have to click away and place lots of points because that is what you do, then use a control point spline. The curves will be better than a fit point spline.

Bad curves can cause many problems later on in a model, especially if shelling or offsetting is involved.