Design within first layer


I have a Rasperry Pi Case designed and what I want to do is insert a design into the first layer. I don’t want and layer differential between the design and the case bottom, everything in on the bottom. So for instance the case is rectangular, for the first layer I want it to print the perimeter of the case and in the middle the perimeter of my design, then infill within both perimeters. Is there a way to do this?


I suppose a work around would be to print the design I want first, and then the object with that layer thickness of the design removed to piece them together. But there must to be a way to do it in one print, right?


Perhaps use images exported from SketchUp to explain what you want ?

(Your spelling [incorrect words] and runon sentences make it very hard to understand what you mean.)


Here is an image for ya. I have a block with a triangle on the bottom. When I send this to slic3r the triangle disappears. I don’t want the triangle to disappear when I print it. I want there to be a triangle drawn into the bottom layer. How can I do this? Is there a way?


So, now we have some pertinent info…

Perhaps coplanar faces are merging ?
Try extruding the triangle - in/out ~1mm from the main face using PushPull ?
Does that help ?


Well yes, the rectangular bottom and the triangle are coplanar. Is there a way to tell sketchup not to merge the two items when exported as an stl?

If I pushpull it in or out it will show up in the print (as long as my print resolution it matches the amount it is pushpulled), however I want the design flush on the bottom.


If the 3d-print material is “one type”, then how would the triangle be differentiated from the coplanar rectangle that envelopes it?
It you want two 2d shapes which are coplanar, then at least form a very thin ‘groove’ between them so they are printed separated ??
As I said earlier the alternative is to extrude the triangle a very small amount in OR our, so that it ‘prints’ separately…


Ok, so what I am trying to achieve is impossible with sketchup then


What should the (any) 3D printer print if there is no thickness at all for the triangle?
It should be possible, printing with 2 materials. But there should be some minimal thickness (up into the rectangular block) for the inserted design.
I’m not familiar with 3D printing so I do not know how two separate solid groups (block and triangle) would best be exported and printed.


Yes, this would be a solution:

No. (And it’s not the problem of SketchUp.)


Well that would be a solution to what TIG suggested as a compromise to what I’d like to accomplish.

Clearly the largest problem is that Sketchup ignores the fact that there is a triangle within the face of the block and allows the triangles that make of the rectangular face to override the triangle design in the face. Perhaps assigning it as a different material and then somehow telling my printer that the secondary material is actually the primary would work? I’ve never printed with two materials so I’m not sure how I could accomplish this either.

There must be some kind of work around without having to compromise a gap in the face layer.

It’s almost like I’m creating a new infill pattern.


[quote=“SteveKing84, post:11, topic:14656”]
…Clearly the largest problem is that Sketchup ignores the fact that there is a triangle within the face of the block and allows the triangles that make of the rectangular face to override the triangle design in the face. …[/quote]
Is this a selection issue where the triangle not selectable without selecting the entire rectangular face (or where you can’t select the rectangular face without the coplanar designed triangle? A face over a face, not merging?


@Wo3Dan: I think he is referring to the slicing process after the export and before the 3D printing.


When I inspect the STL using netfabb, the triangle design is complete gone, and obviously doesn’t show when I slice it.


Could you share the skp file here of what you got so far?


If you want a design in your case you need to carve it in. Drawing 2 dimensional lines on the surface has little meaning to a 3 dimensional printer.


Wo3Dan. See attachment. I changed it to a circle to avoid confusion in case we end up talking about the triangles created in an STL.

edit: I just realized in my haste to give you a file I didn’t reverse the face. Either way doesn’t matter

example.skp (81.4 KB)


jim, it’s looking like the 3D software isn’t capable of differentiating the surfaces. What I’m not familiar with is dual extrusion. If I wanted to assign the design to a different material is that done within Sketchup? If so, that might be a backdoor way of getting the printer to do what I want


You will likely need to create 2 separate Solid volumes in SketchUp. You can not print a 2 dimensional surface on a 3 dimensional printer.


Yeah, that’s what I thought out-loud in post #2.

Perhaps print the design, remove the skirt, then print over top with the design taken out of the main object.

The problem with that is it would never be seamless though…