How to-making diamond points

From the "interesting bit of metalwork" thread came a discussion of how to make diamond points. Years ago I used the method Ed described after reading it in either Moore's book or Machinery's Handook. When I did this cheap diamond was not available. I lucked out when I was given some diamond grit that I then graded. It was already pretty well crushed into many different particle sizes. Now I use the diamond paste that comes in plastic syringes. It is cheap and cuts pretty well and is already graded. For making the points I use brass or cast iron that I turn to the desired size and shape. Then I squeeze some diamond paste onto a hardened steel plate and thin it with some kerosene. I then use another piece of hardened steel to press against the point as the point is rolled along the bottom plate. The pressure doesn't need to be that high. I just lean hard onto the top plate as I push it along and the point rolls between the plates. I do this a few times because the thinned diamond paste squeezes out of the way when the point is rolled across it. It seems to me that if I use the paste without thinning it doesn't charge as well into the point. If you do this you will need to experiment a little to see what works best. I also make cast iron lapping plates for my slow speed carbide grinder. To charge them I lay the plate on the bench, apply the diamond paste, and roll a ball bearing across the plate. I put a shaft through the bearing and press down pretty hard. The hardened outer race of the bearing does a pretty good job of forcing the diamond into the surface of the plate. When the plate starts to cut too slowly I charge it again. The plates themselves do not wear because the work never touches the cast iron if the plates are used properly. I make all sorts of different form tools for turning or milling. When grinding on high speed steel I keep the revs down on the point so that the diamond lasts longer. Kerosene or WD40 make good cutting lubricants for this. When I use care when charging the points with diamond they last a long time. If you don't crowd the point when grinding, if you let it cut at the rate it wants to cut at, it will last a long time. Eric