I've had a nibbler for years. They are VERY air hungry. A 14CFM compressor is generally required to run them without stopping (think 3hp and twin cylinder). The horseshoes it throws out get everywhere. You feel your feet snicking the carpet in the house and realise several have lodged in the soles of your shoes. Keep the cutting bits well lubed and have a spare or two. I've snapped several, usually at times I don't have a spare! A good tip is to use a pair of G-clamps and a straight bit of whatever alongside any straight you wish to cut rather than do it freehand.