Unfortunately, there's a lot of slop in lego gears and axle holes, and quite a gap between blocks when affixed that don't line up when sliding together. I've u

Unfortunately, there's a lot of slop in lego gears and axle holes, and quite a gap between blocks when affixed that don't line up when sliding together. I've used Lego stuff on the job for prototypes and experiments as well. They're overall really good and handy, but some simple mechanical tasks can get really messy or rattly.