Exported a Tinkercad stl file from Tinkercad, but when I imported it to MeshCam and ran the toolpath simulation, the holes had turned into columns, eg they looked like what the “hole” objects looked like in Tinkercad before they were grouped. Before simulating toolpaths, the file looked fine in MeshCam with holes as they should be. Thoughts?
Maybe the tool you chose to cut with is too large? Try changing the tool size in the settings to see if that fixes it.
Also, download OpenSCAM. It’s a free 3d similator that is pretty accurate. That will give you another view of what the final cut will look like.
You can verify the STL file independently of MeshCAM by viewing with the freeware MeshLab ( http://meshlab.sourceforge.net ). It sounds like Tinkercad is a Boolean-type program and the holes were positive solids that were differenced from the main body? If that was done in Tinkercad the STL file (as an “inert” output format) should behave as it looks.