1.when using spline and scaling it I got a deformed spline/2. Why I can't fillet

[luis.lange]

Hi everyone! 

I have two different questions that I would like to share with you to check if I'm doing something wrong.:

1. When drawing a sketch with spline, why sometimes when I scale a spline I got it deformed?

I draw cookie cutters and I need to have it in different sizes, so I create one and scale it to required sizes. But sometimes when scaling it, it deforms. One solution I use is to export my sketch as DXF and import it to the same file and then scale this DXF. It works, but sometimes I got another issue (question 2)

2. Why sometimes I can't fillet a body?

I'm using the same example as above. I draw a spline, export sketch as DXF, import it, copy imported DXF to the first sketch and then scale this 2 drawings. One DXF I can't fillet, but original spline I can. And both scaled drawings I can fillet... Please see in the picture below. Green arrows are "Filletable" and red arrow is not "filletable".

f3d file is also attached.

Thank you in advance. 

Regards,

Luis

[g-andresen]

Hi,

1.  when i tried, the described problem occurred with your splines.
Splines I had created myself could be scaled easily.

I think this is something for the AD experts.
2. The problem with rounding is caused by the many short line elements that are present when reimporting the DXF, but it goes up to a certain radius.

günther

[laughingcreek · Accepted solution]

First off, imported curves frequently cause grief. even DXF files.  It's not a suggested work flow.

-once you edit a tangent handle on a" fit point spline", it won't scale properly.  this is a bug that has been lurking around for a while. (an edited tangent handle is cyan, an unedited one is green. once edited, they stay in that state even when you move control points around. green ones will adjust.  to reset a tangent handle back to it's un-edited state, you can selected it and hit delete).  A "control point spline" doesn't suffer from this bug, but may be harder for you to control.

-in general, you are using way to many control points on your splines.  using fewer points, and adjusting with the tangent handles will give you smoother curves, and better surfaces built from those curves.

-the dxf curves are coming back in dirty, and the curves have a lot of near tangent locations, which is what is tanking the fillet.

my suggestion for your particular situation.

-create your first set of curves on a sketch.

-create a new sketch for your scaled curves.  "project" original curves into this new sketch.

-EXIT sketch mode.

-use the scale in model space to scale the entire new sketch (you select the sketch from the browser).  this scale works different from the scale inside the sketch environment, and will properly scale the entire sketch.

[laughingcreek]

a quick example screen cast of suggested work flow.

unsolicited advice-

-the origin should always have a meaningful location in a design.

-learning how to us components will make life easier as you get to know fusion (for instance, if you like to spread your designs all around your workspace, you can do this and still work around the origin, because every component has it's own origin)

[luis.lange]

Hi Günther.

This scaling problem is punctual, I got by chance this drawing with this behavior. And I think it is not related to any F360 release.

An I agree that DXF is made with a lot of little segment, but also, sometime I cannot fillet with 1,8, but 1,9 yes. And 2 I cannot. Strange... 

[luis.lange]

Hi Alex.

Thank for your reply. I understood your explanation about the tangent handle, but I don't understand why it's not scaled properly. Wherever... Your suggestion for sketch scaling worked here, but I needed to break the connection between original and projected line (and it gaves me a line with a lot of segments, in fact a control point spline) otherwise I cannot move the projected line. And I can fillet the body also....

I have some drawings here to create and I'll use your suggestion. It require some extra effort, but if work fine it is ok for me.

Thank you !

Luis

[laughingcreek]

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@luis.lange wrote:

...but I don't understand why it's not scaled properly.

The tangent doesn't scale properly because there is a bug.

...but I needed to break the connection between original and projected line

Shouldn't have to break the link. are you doing it like my video?

(and it gaves me a line with a lot of segments, in fact a control point spline) otherwise I cannot move the projected line. 

Are you projecting your origial curves, or the DXF?   oh, wait, your trying to move it after you project?  yeah, don't.  leave it in place and toggle visibility on and off.  if you want to be able to move it without breaking the link, learn how to use components.

... It require some extra effort...

May seem like extra effort.  but if you use good modeling practices, makeing changes in the future will be easy, and a lot less effort.

Good Luck!

[luis.lange]

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@laughingcreek wrote:

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@luis.lange wrote:

...but I don't understand why it's not scaled properly.

The tangent doesn't scale properly because there is a bug.

I got it !

...but I needed to break the connection between original and projected line

Shouldn't have to break the link. are you doing it like my video?

Yes, I did.

(and it gaves me a line with a lot of segments, in fact a control point spline) otherwise I cannot move the projected line. 

Are you projecting your origial curves, or the DXF?   oh, wait, your trying to move it after you project?  yeah, don't.  leave it in place and toggle visibility on and off.  if you want to be able to move it without breaking the link, learn how to use components.

Taking my example (it is a footprint and I need to create two different cutters) and after scaling it or even drawing it, I need to create offset lines, in order to have the cut wall and border. And if I don't give them right spacing it will overlap.

... It require some extra effort...

May seem like extra effort.  but if you use good modeling practices, makeing changes in the future will be easy, and a lot less effort.

In that case, more effort mean more reliable, not more work.

Good Luck!

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[laughingcreek]

ok, i see what you mean on scaling the sketch.  

work arounds-

-make a third sketch after the scaling function, project in to it and proceed from there. supper annoying.

-add a scaling user parameter, and apply it to dimensions and offsets before the scaling command, so everything comes out right. even more annoying.

-create a solid from the scaled sketch and proceed from there.hmm maybe...

or just stick with what your doing if it's working for you. probably best.

here's a screen cast of using the third possibility, coupled with components. at the end you can see what I mean by being easier to edit down the road.  you can tweak one sketch, and all the various scaled cutters will be corrected automatically if you can manage to keep everything linked.