Thanks Jim! I'm sure we're going to need them especially since my grandson really wants to try it out.
When I made the first control panel 13 years ago while in Germany, I attempted to drill the acrylic with a standard jobbers drill with very touchy results. A standard 118º drill tip grabs acrylic on the way out and tends to crack the material. It's very hard to control. A drill for plastic has a sharp, 60º tip angle and has negative rake installed at the cutting edge. You do this by grinding a small flat at the cutting edge on the flute side. This is similar to a drill for brass since that tends to grab also. The negative rake results in a scrapping action rather than cutting as with a regular bit.
I looked up prices to buy these drills and, with shipping, would have cost me another $35. Since the components I'm using are German, they have metric-sized threads. I have a nice set of metric drills so I decided to try my hand at re-shaping the tip. I have a very old, but very nice Dayton bench grinder and, as an old metal shop teacher, have no trouble hand sharpening drill bits. I even taught teenagers how to do it.
The plan worked. The reground drills cuts the plastic smoothly without grabbing upon exit.
So I have a design, I have plastic, and I have the tools. Let's make a control panel.
