For making sure that I drill perpendicular to the surface into random large pieces of steel or iron, I can buy a magnetic drill press. Usually pretty heavy duty!
But say I want to make some holes in some enormous pieces of wood, or even wood already part of a large assembly (i.e. my house!) - all way too big for any imaginable drill press - and make sure the hole goes in perpendicular to the surface. Is there a similar tool for this? Doesn't have to be nearly as heavy duty as a typical magnetic drill press, BTW! I'd be very happy with a 3/8" chuck.
I've been doing OK with some plastic and metal blocks to help guide me in perpendicular, but these don't work so well with spade bits etc.
Obviously this kind of tool exists, but so far I've had zero luck even using the correct word for it at the hardware store :-).