Yet another method is find a used but still sharp shell mill that's close to the final diameter and and arbor to fit your mill spindle, then hog out a core sample. Cut from both sides if need be. Then relocate the center of where the finished hole needs to be and finish milling to final.
I did that with a very large steel gear to repair the back gear on a large 1920's LeBlond lathe. It was a very odd one. Outfitted like a screwcutting lathe but with a Rapid Production headstock. Only 25" between centers yet was right at 7 feet overall length. No serial numbers on it anywhere. On Tuesday, February 28, 2023 at 03:00:51 PM MST, John Dammeyer <jo...@autoartisans.com> wrote: Hi Todd, I'm the not an expert and I have no idea about the cutting speeds or depth of cut but here's one idea for you. Generated by AlibreCAM (Unsupported MecSoft VisualCAM) you can program a hole profile to have tabs that hold the middle piece. I created a 5"x5" piece 1.75" thick. Created a 3.75" hole through it. Then profiled the inside of the hole with conventional milling. I've attached a screen shot and the generated G-Code. Hope that helps. John Dammeyer > -----Original Message----- > From: Todd Zuercher [mailto:to...@pgrahamdunn.com] > Sent: February-28-23 12:54 PM > To: Enhanced Machine Controller (EMC) > Subject: [Emc-users] Milling Strategies? > > I need to mill about a 3.75" hole through a piece of aluminum about 1.75" > thick. What is the best strategy to > accomplish this on a cnc mill. Is it best to us a pocketing strategy and > mill out the entire hole from the center > out, or would it be better to use some kind of cutting strategy and mill some > size slug out of the middle? I > can see the first option being simpler, but the 2nd option saves a > potentially useful piece of material, but > with the added complication of how to hold and prevent the chunk of scrap > from wreaking havoc when cut > free. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
