I wanted a plug cutter to cut wooden plugs for fret markers for a guitar I am working on. I with an old bolt.
To form the ‘flute’ of the cutter where the chips clear out, I made an angled clamp block. I just eyeballed the angle I wanted and drilled a hole in a block of aluminum. Then I band sawed through the hole so it would allow clamping. The position of the end mill was also eyeballed. Position seems pretty forgiving.
Below is the confirmation that it works! I drilled a whole bunch of plugs close together. Then I used a piece of tape to hold them all together while I band sawed them off.