Slic3r Prusa i3 MK2 edition problem: filling in embossed models

Hello all,

I am new to the forum and I have a question that hopefully someone knows the answer to. I recently got my first 3d printer a Prusa I3 MK2 and am trying to print something basic before I move to my more complicated existing models. I downloaded the latest Slic3r Prusa edition software and am running into trouble with it changing my models. As a simple example I drew up a coaster with a logo embossed in the middle. The model is complete and watertight with all faces pointing in the correct direction. It appears good in the Slic3r 3D tab. However, when I try to slice the model the software fills in the recessed areas of the coaster and the embossing (basically it takes a detailed coaster and turns it into a solid disk). How do I stop this from happening? I noticed that Slic3r is reporting that it auto-repaired 3142 errors, is it possible that it is auto-correcting away the details of the model? For reference I attached pictures of the Slic3r screens and a STL of the coaster model.

Thanks in advance for your help!

I would say it's not just possible but probable that the repair is responsible. I don't even try loading anything without running it thorough a mesh repair software first anymore.

Any recommendations on a suitable mesh repair software? (Preferably of the free variety)

I'm using Netfabb Basic (which they've apparently rolled into the main Netfabb, but the repair capability ostensibly remains after the 30-day trial of the paid features expires). I've also heard some say they use MeshMixer, which is free.

Silly question - how deep is the embossing, and what is your layer height? If the embossing depth is less than twice your layer height, it may well get filled in by the slicer.

Dave