Using negative volume to provide space for raised image
 
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jlc1978
(@jlc1978)
Active Member
Using negative volume to provide space for raised image

Here's what I am trying to do:

I am making some coasters and use a negative space to creat a cut where I then drop the raised image into.  This insures the coaster has a flat surface for the glass and the glass does not rest on the design, since I is 1mm below the coaster's top.

This worked great on an earlier version of PRUSA slice - I added the negative part, exported as a 3mf file then opened that file, dropped in the raised image in the hole and sliced and printed.  With 2.7.4 MAC/ARM it won't export the cuts to a 3mf or STL file, only the sold surface with an error "Unable to perform boolean operation on model meshes." Searched the forum but did not find a fix.

 

Any suggestions?

This topic was modified 1 month ago by jlc1978
Posted : 16/04/2024 7:38 pm
Eef
 Eef
(@eef)
Estimable Member
RE: Using negative volume to provide space for raised image

You may upload your file here. 
Last time I used this, it worked fine. This is my method: 
- I do not USE a negative part to start with. But Image I want a LOGO on top of a box (printed upside down). 
- I import the box + logo stl. Und scale move etcetera (logo placed on the plate. Box on top of it) You can see what happens when you look from downside (view 2) 
- When I am sure the logo is placed well, I scale the z-direction to the number of layers I want (most of the time two layers). 
- Then in the right panel, select the log, right click and export as an stl. 
- Now the magic trick, click right on the box, add a negative part. 
- Choose for gallery. In gallery import the stl (of the logo) you just exported. And choose the logo.stl (now being a negative part). 
- Now I use right panel, + move to place the negative logo exactly on top of the original logo. (X + Y positions). Just copy past the numbers. 
- DONE. I can print the box (with negative part) in one color, and the logo in other color in one print. 
(Prepare printer profile for to extenders + tool change; you can change result G-code to remove initializing tool change (I don't do that, most of the time I want to check what happens in first layer anyway. Wait untill end of first layer, change color, second layer when color done, change again. And go do something else 😉 

Posted : 16/04/2024 8:01 pm
Eef
 Eef
(@eef)
Estimable Member
RE: Using negative volume to provide space for raised image

PS: To get the logo on another layer then the bottom: 
- create a small box + add negative box (bigger to swallow the complete positive box + add the logo (merge into one object )
And you have a flying object. 
NB: To experiment with organic forms, add organic support, no top-distance (so it will be well attached) and support the flying object. 

Posted : 16/04/2024 8:11 pm
jlc1978
(@jlc1978)
Active Member
Topic starter answered:
RE: Using negative volume to provide space for raised image

Thanks,

 

Here's the file.  I'll try your suggestion as well.

Posted : 16/04/2024 8:42 pm
_KaszpiR_
(@_kaszpir_)
Honorable Member
RE:

there is no file attached to the post (pro tip, do not use attach file, use add media and add zip there)

See my GitHub and printables.com for some 3d stuff that you may like.

Posted : 16/04/2024 9:46 pm
jlc1978
(@jlc1978)
Active Member
Topic starter answered:
RE: Using negative volume to provide space for raised image

Thanks for bearing with this newbie and for explaining how to upload files.  This time there is a file.  Oddly enough, I could get the desired effect with the bottle and glass by using creating a negative volume with the disk that cut all the way through, save the result as an STL, and add it to a solid base. Trying the same with various variants of the cigar would not work, even when I made the cigar a solid object with no lines that look like smoke or ash.; so I wound up just adding it as a negative volume.

 

Book Club Embossed coaster base v8.3mf

Posted : 17/04/2024 9:38 am
Eef
 Eef
(@eef)
Estimable Member
RE: Using negative volume to provide space for raised image

OK. I see it is bit more complex. Do you also have the original for the cigar + text  as you wanted it. The positive ones
Then I will check how to change these into usable negative parts .

Posted : 17/04/2024 11:01 am
jlc1978
(@jlc1978)
Active Member
Topic starter answered:
RE:

Here is a file with both elements.  I tried both as negative volumes but neither would export.  Both were created and saved in InkScape as plain svgs.

 

The text is simply embossed text added via the Add Text dropdown in PS that I select Cut and the depth.

 

I appreciate any insights as to what I am doing wrong,

Jim

Cigar Stick Outline.3mf

This post was modified 1 month ago by jlc1978
Posted : 17/04/2024 1:52 pm
Eef
 Eef
(@eef)
Estimable Member
RE:

OK, I am playing a bit with it. If I understand well: 
- You want this as the bottle and glass. an object with a hollow contour around. Correct? 
- What about the smoke?
Anyway I did some trial and error stuff. This is result: Cigar Stick Outline TrialbyEef.3mf

- Right click on the SVG and change it to a part. 
- (because I don't know how to change it to object. I simply delete all other parts, leaving just the cigar. And then rightclick save to file. 
- To make it an outline I scaled it, but that gives sizing errors, you have to split them in all tiny object. And scale them one by one. !
- Now back to original object
- Choose add negative part -> Gallery -> Add _ Add all the stls made above. And select these to be a negative part. 
- place them on the spot you want. 
- Split original cigar into small objects. 
- Place them on the negative parts. 
Voila SLice and print 

PS, I did not want to spend much time on all the tiny subparts. That is up to you. 

Posted : 17/04/2024 2:50 pm
jlc1978
(@jlc1978)
Active Member
Topic starter answered:
RE: Using negative volume to provide space for raised image

Thanks.

 

Don't worry about the small parts or smoke, I will simply emboss them.  I was really just trying to figure out why I couldn't get the cigar shape to be a cutout that would export as an stl so I would have a negative volume to drop the shape in as I did with the bottle and glass.  I will take a look at what you did.  I really appreciate you taking the time to look at this.  It's strange that some shapes I make work fine and others don't.

Posted : 17/04/2024 3:06 pm
Eef
 Eef
(@eef)
Estimable Member
RE: Using negative volume to provide space for raised image

PS: I suggest making the cigar + outline as two seperated images in InkScape. Easier to line them you want. 
Then in Prusa Slicer you treat change them to two objects, one for the cigar, one for the negative contour. 

Posted : 17/04/2024 3:07 pm
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