This machine never worked the way it was advertised to.  It cannot handle urine, the urine clumps and scooper gets caught on it.  This stresses the motor out to were it resets itself, thus not scooping anything.  Or if it does break through it, the clump crumbles to small enough pieces where it slips through the scooper and quickly starts to stink.  I tried five different types of litter, nothing improved the machines performance.  I ended up keeping a hand scooper and plastic bags available as I had to scoop and clean it myself.  The plastic mounts on the scooper ended up snapping of after two months of use.  The box is just messy and useless and hard to wash as you have to disassemble it. You might as well buy litter tray for $5, it will function 100 times better.  I use a plastic concrete mixing tray you can get at home depot for $6.  It looks just like a litter tray except it is about 2' x 3'.  If you got the room this is the way to go.