Sharpest corner + Hide seam: Improvement needed?

[sadpunk 0]

Hi!

I'm trying the Z seam aligment: Sharpest corner + Hide seam to improve my prints.

But I am getting mixed results.

It looks like Cura, sometimes ignores this options and places the seam randomly, making the scars more noticeable.

Below there's an example of a 3Dbenchy.

I believe that the seam should be on either of the corners (black arrows) and not on a straight line (black circle)

Please note:

I'm on cura 3.0.4

I print "outer before inner walls" + "infill After wall"

Thanks!

[burtoogle 513]

Hi, if you want the seam to be on the "pointy bits" of the outline you should use "expose seam" and then it will locate the seam on the most convex curve of the outline.

However, at the moment it is suboptimal inasmuch as it bases the curvature calculation only on the curve between adjacent points on the outline which makes it very sensitive to outlines that are not smooth. It would probably be better if it averaged the curvature over some distance. Perhaps, I shall take a look at that...

[sadpunk 0]

Hi Smartavionics,

Hi tried the "expose seam", and it did change the seam place.

But not always to the "ponty bit"

Thanks for the support

[burtoogle 513]

Hi. Yes, it's not working quite right. I am looking into it now...

[burtoogle 513]

I've fixed a problem with this code and submitted it for inclusion in the next release:

https://github.com/Ultimaker/CuraEngine/pull/653

Sorry for the inconvenience.

[sadpunk 0]

Thanks!

[amagro 3]

Hi @smartavionics,

I really like the new seam strategy "Sharpest corner + Hide seam" but I think it need even more optimization. In round faces the seam never stays vertically aligned as we can see in the image bellow. Any chance to solve this "issue"?

Thanks

[burtoogle 513]

For a cylindrical shape like that you will get best results using the User Specified z-seam alignment along with some suitable x/y values. This will align the z-seam across layers. However, you can still specify a seam corner preference and what that does is move the z-seam from the position that it would have given the x/y values and the shape of the part to a nearby convex or concave corner. You can even control how much influence the corner will have on the z-seam position by varying the x/y values (while keeping the ratio of x to y the same). The larger the values of x/y the more influence the corner will have. Have a play with it, there's quite a lot of control there.

[CREAR3DCBA 0]

On 6/12/2017 at 16:25, smartavionics said:

Para una forma cilíndrica como esa, obtendrá mejores resultados al utilizar la alineación de costura en Z especificada por el usuario junto con algunos valores x / y adecuados. Esto alineará la costura z a través de las capas. Sin embargo, aún puede especificar una preferencia de esquina de costura y lo que hace es mover la costura z desde la posición en la que habría dado los valores x / y la forma de la parte a una esquina convexa o cóncava cercana. Incluso puede controlar la influencia que tendrá la esquina en la posición de costura z variando los valores de x / y (manteniendo la proporción de x a y la misma). Cuanto mayores sean los valores de x / y más influencia tendrá la esquina. Ten un juego con eso, hay bastante control allí.

Doing tests with this help, I could not get a perfectly straight seam. I believe that there is a need to improve the alignment of the seam on curved surfaces, so that the entire seam is in the same vertical plane. Slic3r presents a better seam on curved surfaces, completely straight.