Slic3r Infill

Hi. I can't seem to find a clear answer to my question about Sli3er. I'm a little confused about the infill option. I understand what it does, but not quite when it does it. I originally thought that after the printer lays it solid bottom layers, it would use infill only for hollow space that is enclosed. So using OpenSCAD I made a my part hollow in the middle with determined sidewalls. When it was printing I noticed it was using the honeycomb infill pattern in the area I did not make hollow. So long story short, when does Slic3r decide to use infill? Do I have to make parts hollow? Not extremely difficult, but takes time and don't want to do it if i don't have to.

Thanks

You are confusing "support" with "infill". Infill is just the inside of a solid object. You select the "percentage" of the infill you want. So going back to math class. 1 = 100%, .70 = 70%, .50 = 50%, etc... This is how much plastic you want to use on the inside. Take for instance a plank of wood. It's solid. 100% infill. Now you want to fake the wood. You might use wood veneer for the "borders" or walls. That's essentially the outside. Now you want a small infill this will be full of air. So you use foam. Lots of air and you can glue the veneer to the outside. Now if you have a hollow box without that infill or the foam your top layer will be extruded over empty air. To hold that layer up and flat you'll need the support material to hold this up. You can select support and infill pattern. This is why you had a honeycomb pattern. That is what your support material pattern was set to.

Okay, I understand. I didn't know you there was different options for support pattern (simple mode), so when I seen the honeycomb I assumed it was infill. So just to make this clear, if i create a solid cube, it will fill the middle area with "infill" based on the percentage I set. If i creat a hollow cube, it will fill in the middle area with "support" based on the settings set in that catagory. Is this correct?

Thanks

Yes. The support will only print if the box is checked. If you don't want support printing, clear the check box.

Perfect, thank you for clearing this up.