Greetings Bob, I'm curious about your description of the faults of round over cutters. I use some HSS ones but for steel I use mostly carbide cutters. In fact, I use carbide cutters almost exclusively now. I have old HSS ones in many sizes and only use them when I don't have a carbide one. If I have to do a lot of milling I buy another carbide one if all I have is the HSS version. But even the HSS ones cut accurate radii. As far as neding extra mayerial all the cutters I use would be able to mill the bosses as shown. I also have and use cutters that can mill the bosses in one pass but you would need to stand the molds up which would require another setup. One of the reasons I like the carbide cutters is that they are ground with a finer finish so the parts look better. I also sometimes use carbide router bits meant for wood to machine metal, even stainless steels. They typically have a pretty rough grind on them which leaves a poor finish on the parts. To correct this I make a brass lap, charge it with diamond paste, and lap the router bit cutting edges to a much finer finish. This process doesn't take long. Carbide router bits have saved my butt a few times when I have forgotten to order a cutter or when a cutter fails for some reason. Living on an island makes getting cutters in a hurry tough. Eric
********************** I have only purchased a few round over mills, but they all have all seem to have a slight angled lead to the radius area. Also, I haven't found a standard for the overall geometry and dimensions for the rest of the cutter that I can use to program the cut. I use them all the time to rough radius the end of alignment pins on the lathe, but on the mill I would only use them on outside edges. The inside edge needs a clearance cut on those I have in order to cut the radius. I did that before, but I only over did them on the manual mill to finish after the mold was complete. I never cared for it. That was time I WAS NOT spending doing design and setup work.The other issue I have is power and speed. The round over mills really are not IMO well suited for high speed milling. I can't low speed mill on the
24K high high speed spindles. They really have about zero torque under 10K.Oh, yes. I have used router bits in a pinch many times. Since I also have a small CNC router I do have a decent selection of router bits on hand at any given time.