I have a new lathe job to program that requires a fair amount of metal removal using a trepan tool. A core drill would do some of it, but we don't have one and wouldn't buy one. 2024-T4 aluminum. Using a K-Drill (which gives a very nice flat bottom) to go to Z-.553. There are two sections below this depth that require the use of a trepan tool, but I'd like to go in with a 1/4 inch endmill in a live tool to remove the material in the first section. Need to go .128 deeper. Finish diameters are 1.188 and .563. Will leave .01 on both diameters for finishing with the trepan tool.

The only way I know to use the 1/4 inch endmill is to use a G112. I'd have to either plunge straight in with a center cutting 2-flute endmill or add another tool to drill a hole first for the endmill.

What I'd really like to do is ramp in as the tool moves around the arc. Problem is G112 does not allow any Z-axis moves. Any of you brainiacs know of another method to accomplish this goal? Thanks.