The small lip (top) and short insert (bottom) prevent mugs from sliding off of one another.

EDIT: Added two new variations: 

• Variation 1 has the center punched-out, using 25% less material and reducing print time by ~16% (On my personal slice settings) compared to the original
• Variation 2 also has the center punch, but now has the lip extend down as well as up for a bit more stability. ~20% less material and ~9% reduced print time vs Original.

I wanted to stack our mug collection to display, but I found out that simple cylindrical mugs don't have any standardized sizes!

I measured a bunch of mugs and found they usually fall within ~10-12mm of each other in diameter, so I made this to fit most everything in our collection (including some slightly smaller ones).

I found for most mugs there's a bit of play due to being sized for a range of mugs, but once stacked they tend to not shift around as much. Putting some sort of rubber or foam sticker on the top and bottom of the contact surfaces would mitigate this.

Printed in PLA, top-facing-down orientation seems to be the most time and material-use friendly for supports. I use a small flat head screwdriver to work around the inner lip; gently prying towards the supports will cause them to flex and pull away from the main surface.

Sliced in Cura

Infill Density: 3%
Infill Pattern: Lines

Support type: Normal
Support pattern: Grid
Support density: 8%