...When drilling polycarbonate, PETG, plexiglass etc, a fluted drill bit can catch into the plastic and either quickly be sucked into the hole, chip the plastic or worse, crack it out from the hole.
Over the many years of fabricating machinery guards and other around the house and motorcycle plastic fabricating, I've gotten very used to using stepped drills. ...
I always thought steppped drills meant working your way up the drill pack to enlarge a pilot hole - consider me now more educated!
PS: great thread - just ordered my screen last night.
PaulV,
I would not be against using a very small, say a 1.5mm standard fluted drill as a pilot to create a hole to follow. The stepped drills alone can start without any pilot at all in steel and plastics. But the small drill to follow would keep the stepped drill hole centered without any side creep from the correct location.
In thinner sheet metal, standard 2-fluted drills will make a 3-sided hole. How they do that is beyond me, but they are NOT pretty that way.
You can also use the next step up to de-burr your final hole on both sides for a great looking finish.
I probably have 9 or 12 of these at home of varying sizes. They come in a 3-pack usually. I like the long stepped bits the best, but sometimes they don't have the sizes I need.
I hope you all have a great weekend...
