BTW, your suggestion to sink the model into the bed a layer or so (I didn't know S3D could do that!) completely fixes the problem-- at least in Preview. Thanks! I'll be trying it out today.

I am replying to you guys, honest. It just seems to take a long time to get my replies approved. Is there some metric that must be passed to be able to post messages without moderation?

Well, after beating my head against this for a couple of hours, the answer is: the "customizer" on Thingiverse produces crappy models. My solution: design my own from scratch in Sketchup. (And yes, I did confirm that the ring hole is the first layer using Simplify3Ds preview mode. GOD I love that fe...

I'm trying to print a simple key ford design I downloaded from Thingiverse. The key fob is an oval, with a bulge at one end for the hole for a key ring. Simplify3D's default settings are to print the first layer-- this is Makergear PLA, BTW-- at 50% speed. When I start the print, it prints a small s...