...Sometimes, it just won't work...
I thought it would be neat to make my P-08 rear toggle knobs 'dished', like the M1900 toggle knobs. So, I took measurements from side-on and top-on photos and figured out that the 'dishes' were cut 10º from the vertical axis. I also figured that to give me a straight-in cut with my end mill, I need to angle my mill vise 16 1/2º from the horizontal axis. My vise is adjustable, so that took care of the 16 1/2º, and I made up a fixture to hold the toggle at the required 10º [Pic below].
I had previously test-fit various shot glasses, jelly jars, lids for whatever I had that used lids, and determined the diameter of the M1900 dish to be 50mm/~2". My biggest end mill is 1 1/2", used to mill off flash on AR-15 lower receivers. Anything bigger would run several hundreds of dollars, which I wasn't eager to spend for 'dishes'. The 1 1/2" end mill would have to do.
When I got it all completed and set up, it didn't look right. After many years of machining, I have a rough eye for what I am doing. This wasn't right.
It turns out the M1900 toggle/knobs are .150" wider than the P-08 knobs. That threw my straight-in measurement off. I'd need to increase my angle. But then the dish wouldn't be right - the cutter is too small for the narrower knobs. The dish wouldn't look right.
I could mill the dish flat, instead of concave. But that's not right either.
In the end, I shelved the 'toggle dishing project' due to lack of tooling. A few days wasted making the fixture and taking measurements.
Sometimes you eat the bear...Sometimes the bear eats you...
