My current project is a bookcase. When I worked out the design I chose to add a simple decorative cutout to the side panels. Nothing complex, actually a fairly common motif, four intersecting circles. Once I decided to add it, I immediately began thinking of ways to actually cut the four circles.
There is the tried and true method of drilling a small access hole, threading in a coping saw blade and cut away the waste. Then clean up everything with a rasp. This would work, but can be tricky to keep the circles exact. The thing with simple is that it looks best if it’s executed exactly with the utmost precision. So I began looking for alternatives.
I have a brace and a set of auger bits and I use them all of time for my larger drilling needs. Heck, I even use it for driving screws on occasion. I’ve read about and seen photos of an expansive bit that can be used in a brace to drill/cut large precise holes. A quick search on Ebay and I found a decent quality example and hit the “buy it now” button. It arrived soon after and out to the shop I went for a test drive.
Like the box says, it will bore holes from 7/8″ to 3″. There are two cutters to span the range and you slide the cutter out to the radius of the desired hole (I need my holes to be just under 3″). Chuck the thing in the brace and turn away. Should be easy, right?
The expansive bit works as advertised. A nice clean, large hole. As per the usual, you go half way through from one side and then finish off from the other. What I hadn’t factored into the equation was how much force it would take to peel an 1-1/2″ swath of wood. Holy crap! I’ve gotta’ do it eight times to complete the design on both panels. Not sure I’m man enough for that all in one go. I may have to spread it out over a couple of days.
It does produce a nice hole that needs minimal cleanup and you get a nice saucer shaped puck as well.