Unnecessary Support Placement

[Spengler 0]

I have a question regarding support placements.

In the attached pictures you can see that the overhang of 45° and the tubes on the right are not marked red, only the holes. But Cura still puts unnecessary support underneath. Why does this happen?

 

The support overhang angle is set to 65° and it doesn't matter if I change it to 50° or 80°. All other settings are set to recommended.

The support blocker function isn't helpful aswell.

 

Thank you.

 

Edited January 10, 2019 by Spengler

[burtoogle 513]

There's a setting called something like "use towers" that makes stuff like that, if you have it enabled, try turning it off.

[xTremePower 0]

I think you simply don't understand how to use support blocker ....

You need to clic on Support blocker icon, here a gray cube will appear
You need to drag and scale the cube where you don't want support

DO NOT put the cube on the buildplate or on the support, just on the face where you don't want the support (like on your big tower support top )

[Spengler 0]

On ‎1‎/‎10‎/‎2019 at 5:46 PM, smartavionics said:

There's a setting called something like "use towers" that makes stuff like that, if you have it enabled, try turning it off.

This setting was turned off.

I read ALL the discriptions of the other settings, but I can't find anything helpful. :-/

 

On ‎1‎/‎10‎/‎2019 at 7:15 PM, xTremePower said:

DO NOT put the cube on the buildplate or on the support, just on the face where you don't want the support (like on your big tower support top )

Thanks  @xTremePower, but I put the support blocker on the face, as you said, but it does not block the support.

I tried different Blocks as you can see in the attached pictures:

- From underneath the platform to the middle of the lower hole

- Just on the face, as you said

- around the surface and above the lower hole

But nothing happened.

 

If I put the support blocker around both holes (and not on the face underneath, which I want to focus on) the support is removed (last picture). But the supports in the wholes are necessary, so this is no option either. This is why I said, the support blocker function isn't helpful.

There must be a setting for this, but I can't find it...

 

There are 8 other areas in this part, where this happens and I want to print this part 5 times, this means a lot of unnecessary PVA (~900 g).

 

Thanks for your help!

Edited January 31, 2019 by Spengler
spelling

[gr5 2,167]

Hmm.  Looks kind of like a bug.  If you had "support horizontal expansion" at the default of 3 still then it would make sense that it's connecting those upper 2 support areas down to the bed.  But it looks like maybe you set that to 0.  Maybe you didn't go far enough.  Maybe you need to set it to negative slightly to fix this issue?  Try -0.1 so that there is definitely no vertical path from the upper supports down to the bed.  Or maybe I can't see that on the backside those two tabs with holes are not exactly perfectly above each other and you need to set horizontal expansion greater than the misalignment.

 

In this specific case you can just block all support as you don't really need it for those circle holes.  it will be a little bit ugly but mostly functional with possibly a little filing (or you can drill it out after).  I don't know if this helps with your other 8 cases.

[Spengler 0]

On ‎1‎/‎31‎/‎2019 at 4:17 PM, gr5 said:

Try -0.1 so that there is definitely no vertical path from the upper supports down to the bed.  Or maybe I can't see that on the backside those two tabs with holes are not exactly perfectly above each other and you need to set horizontal expansion greater than the misalignment.

Thank you for your help, but unfortunately that did not work either. I tried different values for "support horizontal expansion" from -0.5 to 3, but the support just got a little bit thinner .

The holes are exactly perfectly above each other, I designed it by myself and exported it in a very high stl resolution, so I'm absolutely sure about that.

 

I can't leave out the support for the other 8 cases.

I also tried slicing this with an older cura version on another computer, but same issues...

[tinkergnome 927]

Don't worry, AFAIK it's a bug since Cura 3.5 and should be fixed in the 4.0 BETA version.

So: wait for the next Cura version or use Cura 3.4.1 if you need it sooner...🙂

 

See:

https://github.com/Ultimaker/Cura/issues/4583