I have a Roomba. A 550. I got it about 6 weeks ago at Costco.

It’s great when it works. It’s not so great when it breaks. It broke on its six week birthday. The two roller brushes just stopped spinning.

I’m no mechanical engineer, but I know trouble when I see it, and I’m pretty sure that every 500 series Roomba will eventually break down. Here’s why.

Roomba’s got two brushes. On the left is what the end of one of these brushes looks like before you start cleaning. On the right is that same part after a normal cleaning cycle.

(I promise I’m not dirty. I just have two (short-hair!) cats.)

See, there’s a gap at the end of the roller. That means that instead of being rolled into the collection bin, a fair amount of hair and debris gets caught up in that gap. Eventually (six weeks in my case) that junk makes its way into the gearbox where it jams everything up permanently. This has happened to lots of other people too. Power is applied, motors meet resistance and heat up, the plastic gears melt, and the brushes will never spin again.

I did everything that I was supposed to. I emptied the bin and cleaned those rollers religiously after every cleaning. Every day. (Roomba’s novelty wears off pretty quickly when you realize just how much work you have to do to keep it running.) Six weeks of daily vacuuming trips around my two-cat, all-carpet house was ultimately more than Roomba could handle.

Rather than deal with shipping the whole thing back and dealing with iRobot’s infamously unhelpful customer service, I just packed it up and brought it back to Costco, whose lifetime return policy is legendary.

I walked out with a new Roomba, but I’m almost positive I’ll be back in another six weeks to do the ol’ switcheroo. Again.

Way to get it right on the fifth try, iRobot. So glad I waited this long to sample your wares!