When you install a lift-the-dot fastener, you have to make a hole (about 5/16" diameter or a little larger) in the fabric for the mounting stud to pass through. As I was doing both a convertible top and a tonneau cover, I thought I should have a suitable punch rather than having to cut all the little holes by hand with an X-Acto knife. Not having such a punch immediately at hand, it was time to get creative. In my bits bins I happened to find a 5/16" diameter x 2" long spring steel roll pin, so I decided to make a dinking die (well at least that's what my dad always called it). This is a one piece punch and die, so without the die half it's really just a punch with a sharp edge.

First I used a pedestal grinder to dress off the end of the roll pin to remove the traditional outer chamfer and produce a flat end with a sharp square outer corner. Then I chucked up a conical grind stone in the Dremel tool and proceeded to grind a conical recess in the end of the roll pin. This left the roll pin with a nice sharp edge suitable for cutting through most any thin stock which is softer than spring steel.

To use this punch, just put the material to be cut down on a soft board with a solid backing and give the punch a good whack (or a few gentle taps) with a hammer, and you have a hole the same size as the punch. Since this punch has an open slot down the side, I also have to rotate the punch slightly and give it another hit to finish cutting the last bit of fabric that the gap misses on the first hit. That slot does make it easy to clean the scrap out of the punch with the tip of a small screw driver or knife blade.

Home made hole punch

Here's another home made hole cutter idea from John Pipe.

Select a small socket of the right size. Used the Dremel or other, to grind out a the center. Mine started to grab after a few seconds, so I used a grinding wheel around the outside to give a cutting edge. Then attach the modified socket to a drill and drill out the hole against a wooden backing plate.

Home made hole punch #2