I recently purchased a cheap step drill bit off of amazon to drill a 1 and 3/8 inch hole on an acrylic aquarium for a bulkhead. However, it seems to be very bad at doing so. It is so slow and I worry about it cracking the acrylic. Would tracing the bulkhead onto the acrylic with a sharpie and cutting out the circle with a coping saw work, or do I need to drill the hole? Thanks in advance.