Deep drilling on cnc lathe

[jackson]

I am drilling .250 X 5.25 deep in 303 s.s. im just looking to see if anyone had any good ideas on running this,any suggestions on feeds and speeds and depth of my pecks and amount of retracts i have a solid carbide oil through drill with 7. of cutting lenth

[cdlenterprises]

I ran a TiAlN coated Titex drill in 17-4 @ 2055 rpm and .0035 ipr. I started at .001 ipr until the tip was started and then went up from there. They (Titex) claimed that you didn't have to peck but I did. I drilled the 1st inch, pulled out, drilled another 1/2 inch pulled out, etc.. I basically stepped down the deeper I went. I was only going 3" deep though. 5.25" with a 1/4 inch drill....that's deep.

[jackson]

Yeah the first drilled i ran was a carbide tip i ran a bit slower than that i was fast pecking then retracting all the way out i did that several times i got about thirty patrs and broke it so i got this HIGH dollar drill and now i dont want to run it HA HA

[HuFlungDung]

Jackson,
You're supposed to buy a tool like that about a year in advance, so you can admire it. Then, when the thrill of newness is gone, you get fed up and use it. Oh, BTW, you should order 2 if you want the first one to last forever

[jackson]

HA HA HA HA yeah i should have cause now i have to go set it up just cant bring myself to let someone else break this pretty sob.

[RICHARD ZASTROW]

jackson, You might consider thru the tool high pressure (air + coolant) blast. I asume you have an enclosure around the machine. With enough flow, you may not have to peck your way thru. I believe the drills are available down to 3/16".

[jackson]

Yes sir that is what i have. oil hole drill and i do have great preasure but im not sure i got the stuff to try drilling with no pecks

[timlkallam]

I ran job on my cnc lathe last week it was a .25 hole 6 inchs deep. I tryed some parabolic drills but the holes would drift a few thou.bad surface finish lots of pecks.
So i tryed a gun drill i bought it from sterling drills
I called them and they said i would need a least 900 psi coolant pressure not to have to peck any less an I would have to peck I only have about 65psi on my lathe. Anyway
I bought one and it worked great i had to peck but it was
alot better than a twist drill the hole stayed stright and the finish was like a miror.
http://www.sterlinggundrills.com/dee...undrills.shtml

[jackson]

what was your speeds and feeds and what was the cost. this carbide i have is "recomended" at 230 sfm .008 ipr

[timlkallam]

The gun drill was around $70 ,I ran it at 3500 rpm at .001 rev. The gun drill tip breaks the chips up so the coolant
can flush the chips out. The slower the feed the smaller the chip. It took about 2 1/2 min.per hole. It worked much better than the Guring and Tidex parobolic drills I tried. If you use a gun drill you must use a pilot hole the same dia.to start it.

[jackson]

how deep were you pecking before retract