My latest mistake was quite stinky… set my vent and fan out the window, turned it on and turned the speed up to cut mirror acrylic, which is very very stinky. About a minute in, I’m like “I thought I took care of the venting issue with the inline fan? How come the smell is so strong?” Whelp, forgot to connect the vent house to the exhaust hole. 
Very stinky mistake!