How do I fix the floor to this 3d box?

Is this post in the right category?

I have a 3d print that’s a box but the bottom keeps coming out all grainy. I just want a solid bottom. When I slice it, the colors show this layer being a “bridge”. Is it an issue with the 3d model? I’m trying different things in blender.

post a pic of it loaded in the slicer, but yeah sounds like a problem with your model or orientation on the bed. A pic would help.

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Does this help? All the sides, and everything else prints fine.

are you using supports? if the inside of the box is under it you need supports
its too much of a gap for it for bridge with out looking like it did. id would print it the other way with supports on. and it will look good.


the best option is remove the legs so the bottom is level to the bed, no supports needed. use pegs to make it easy to put the legs back on after print.


Good idea, thank you!! I’ll try roating first, then try the pegs.

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You can simply cut the model open in the slicer and add the appropriate connectors. However, you will see a cut edge on the model afterwards when you have put it together. So choose the cut carefully.

Best regards!

I would not put too much effort into this, it will be hard to get it looking really good.

If you want it anyway, print a thin 1-2 mm plate with the exact sizes and glue it in afterward. You will have a perfect surface on the inside then. You can also design a little clip if you want to avoid glue. This would also avoid the visible cut line on the outside.

I may have gotten distracted by the other image posted. Your picture looks like it’s bridging, but also on the top surface. Could you please post the full model picture to be able to get a better idea of how the box should look like? and how you added it to the slicer.

If this is the upside in the shown image. You may encounter the following issues.

  1. Your infill is too wide spread so the initial bridging fails and this is a follow-up result.
  2. You have not enough top layers. You will need more than one on this. 5 is usually fine and it will more or less smooth out all imperfections layer by layer.

If this is the underside, please see above.