However my 3d Design skills are letting me down.. Need some tutorials to get these stl's to printable

I've created this in Wings3D it's coming along nicely, However there's problems with the model because it won't run through slic3r

If anyone has any helpful hints or tutorials please comment or private message me.. I'd really like to get better at this

I can see from the thingiverse's rendering of the stl file that it's probably the bottom of the design which is causing it to fail.

Attempt #2: Attempted repair in Netfabb, Joined offset vertices using the flatten function
Attempt #3: Inverted Mesh Seemed to help.. Still not Slicing though, Thingiverse Render of stl still seems weird.. I am giving up for a couple of days
Attempt #4: AHA! It's just amazingly tiny.... Slic3r set to 80x scale and voila
Attempt #5: This isn't a working model yet. However it is designed correctly now with a lid. Just have to make the lip and add a gear system to the lid so that the stepper motor will work.