Can I make one area on a part solid?

[Jerrymc3 0]

I'm making parts for a B737 Throttle Quadrant.  One of them broke because it needs to be solid in that area rather than infilled.  Is there a way to make a certain area of a part solid?

[gr5 2,167]

Yes you can but I don't think it will be any stronger.  Instead you should put a fillet in that crack.  Tight inside angles put all the stress on one line of your part.  with a tiny fillet it will spread the load more.  Alternatively make the outside thicker (the thinnest dimension).  The strength is cubed the width so 10% thicker gives you 1.1^3 or 33% more strength.  Twice as thick is 8X stronger.

 

Anyway here's the answer to your question:

 

[GregValiant 1,243]

@gr5 covered the Support Blocker / Mesh Modifier way to do it.  I started wondering about making adjustments to STL files when you don't have the CAD model to work with.  I drew a 1 x 1 x 1 block with a 1mm R fillet, brought it into Cura along with your SpeedBrake part, scaled it, placed it (the rotation is tough) and then sliced it.  Nice.

As shown - I scaled the fillet model 3 x 3 x 25.  It then has the effect of a 3mm R fillet.  Using the fillet and a support blocker as @gr5 suggests (with the overlaps set to 100% infill (or lots of walls)) and I think the part would be about as good as it's going to get using FDM.

 

Attached you will find one fillet in kit form.

 

1x1x1 Fillet.stl

[Jerrymc3 0]

I'm using Cura 4.7.1 and I couldn't find a couple of the settings gr5 used.  I used your fillet but that wasn't where the break was, it was at the top. I think I need to make that whole end where the curve is completely solid but I'm still not understanding how to do that.

 

Jerry

[GregValiant 1,243]

1. Add a support blocker.  It's going to be used as a Mesh Modifier.  In the object list on the lower left of the screen it's called an Eraser.  You can select it there.
2. Move it and scale it to your satisfaction so it covers that whole end of the part.  When scaling - turn off "Uniform Scaling" to make each axis independent.  When you're happy with the location make sure that the support block Z is at 0.  If you find that you need to rotate the block you should do that last.
3. Select the support blocker.  Select "Per Model Settings" (the tool above the support blocker tool).  Select the third option over - "Modify settings for overlaps".
4. Wall thickness and top/bottom thickness are defaults and you can set them to high numbers.  You can choose to add "Infill Density" and set it to 100%.

Slice the model and check the preview.  Everything covered by the support blocker should be solid and the rest of the model should reflect your regular Cura settings.

[gr5 2,167]

Cura keeps changing slightly how to use mesh modifiers since that video was made.  But it's only slightly different from the video.  Look around in the gui.

[Jerrymc3 0]

Quote

In the object list on the lower left of the screen it's called an Eraser.

I couldn't find this in Cura.  However, I went into Blender and made a curved block to fit the part and inserted it in Cura.  I hope this does the same thing.

 

Jerry

[GregValiant 1,243]

It's the object browser on the lower left of your screen shot.  You can select things there.

 

In regards to your fix - Once you get everything located correctly do a SaveAs *.3mf.  Then group the models and export them as a binary STL file.  Clear the build plate and bring that new file into Cura.  It will be one part.  Sometimes that makes for better slicing but look closely at the preview because sometimes it can lead to unexpected results.

[Jerrymc3 0]

What does the green at the top of the model indicate and how do I tell whether the area is infilled or solid?

[GregValiant 1,243]

Below where it says "Prepare" there is a tool called "Color Scheme" that controls what you see in preview.  Pay with it a bit.