Here's a simple project I did today to make some knobs. These are threaded so they will tighten up on a bolt to secure things. They can be bought pretty cheaply, but not if you don't want to leave the shop. The material I used is pvc, reclaimed from scrap pieces of 2 ft diameter water pipe. Cut into pieces, heated in the oven, flattened, etc, to become a useable material. Bla bla bla. I table sawed enough cubes to make 15 or so knobs, even though I only need about five right now. I drilled and tapped a carefully centered hole in each one.
Anyway, from the top left and going down: first image shows some completed knobs, some blanks, a jig, and a deburring tool.
The jig is just a piece of scrap to hold the pin, which is 3/16 diameter to fit the pilot hole size for the 1/4-20 threads in the blocks. Bottom left pic shows the jig positioned as it is used. Top right pic shows a block on the pin, positioned up agianst the square and with the pin brought up against one side of the t-slot. Note that the jig itself doesn't touch the square. Obviously, some hardware is clamping things in place. The hungry endmill hovers just above-
In the next pic, two sides of the block have been hollowed. I haven't shown it, but I put two pieces of tape on the downfeed handle area to give me a reference point to stop at, so I could get the depth of each cut the same. I snugged up the quill lightly and used the drill press handle to feed the endmill. This pic also shows more of the square I came up with to give me reference edges to work with on the mill. It can be bolted down in each t-slot, so it becomes very rigid- the center slot is being used here to handle the clamping hardware.
The final image shows the stub on which I mounted the blocks for final turning after the millwork. The nut is there to prevent the knob from touching the chuck jaws. This prevents the knob from skewing as it tightens on the stub, thus allowing the knob to run true to its threaded hole, which is good for facing the ends of the knob.
The deburring tool is just a piece of bandsaw blade with a few different curvatures ground into it. Every now and then I put a regrind on them to keep them sharp. It's easy to drag across a sharp edge to leave a very slight roundover. I use this on aluminum and steel as well, it does a good job.