Poop Bucket Retention
I needed a poop bucket to catch my filament purges during colour swaps on my 3D printer. The printer sits on a rolling tool chest, so I designed a bucket that used 4 10mmx2mm magnets to hold the bucket to the tool chest and catch the purged filament. I was originally going to go with 6, but found that would have been overkill. Four magnets work perfectly.