https://forums.autodesk.com/t5/machining-discussions-forum/drilling-aluminum-full-or-partial-retract/m-p/6098766#M4482 <BLOCKQUOTE><TABLE border="1"><TBODY><TR><TH>hoser1 wrote:</TH></TR><TR><TD><BR /><BR />Holy slow batman!&nbsp; When in doubt with 6061 you should peck a lot though, so this is very safe.&nbsp; If you need to run production you will just have to find the sweet spot with feeds and speeds and pecking depth.&nbsp; For comparison, I run a 17/64 parabolic HSS drill from Mcmaster Carr ($15 or so) with low pressure flood coolant at 4000 rpm, 60 IPM plunge, 0.850" deep in 6061 (no pecking).&nbsp; Thousands and thousands of times.<BR /></TD></TR></TBODY></TABLE></BLOCKQUOTE><BR /><BR />At first I did a few test cuts pecking without full retract and the chips were getting stuck in the flute.&nbsp; I don't have flood cooling on my Tormach, only mist.&nbsp; I want to try one of those parabolic bits, I'm gonna order one from McMaster and do a few tests.&nbsp; I attached a picture of the fixture plate with the holes drilled.&nbsp; I still need to tap them.&nbsp; I'm gonna do that on the Haas TM2 (circa 2005) with rigid tapping. The reason I did all the holes on my Tormach is I want to learn about using the Tormach (I just got it).&nbsp; Although, when I need to make another fixture plate I may do the whole thing on the Haas. It's has flood cooling and a tool changer.&nbsp; I could set the whole thing up and just let it run.<BR /><BR />Another little issue I had was my fixture plate takes up most of my Y-axis travel. I had enough room to get a 7/16 end mill to do the long sides of the plate, but not enough for a larger diameter end mill.&nbsp; So there was some chattering. For the short sides I had plenty of room and used a 3/4" end mill - it did much better. <BR /><BR />Here's links to some pics of the surface finish<BR />7/16" mill: https://goo.gl/photos/cFT6qeyp3WbXb4KR7<BR />3/4" mill: https://goo.gl/photos/4LShJRiKmQiGJ1hq5<BR /><BR />Here's a link to a short video clip of cutting the side with the 7/16" mill: https://goo.gl/photos/vQHsBPCU9toUYhfQA<BR />0.05" Doc, 3815 RPM, 30 IPM.&nbsp; I tried both climb and conventional milling on the side cut, they both performed about the same.<BR /><BR />I'm just getting started with CNC machining, so every time I make something, I'm learning something new:)&nbsp; <BR /><BR /> Sat, 31 Oct 2015 02:58:35 GMT SGoldthwaite 2015-10-31T02:58:35Z