Drilling Multiple Diameters.
Drilling Multiple Diameters.
(OP)
Hi.
When Drilling multiple holes on a lathe, all to different depths, is it always smallest hole to largest hole or is it sometimes beneficial to start with the larger holes first to save the smaller drill or for any other reasons (concentricity, finish, etc)
Thanks
Jordan
When Drilling multiple holes on a lathe, all to different depths, is it always smallest hole to largest hole or is it sometimes beneficial to start with the larger holes first to save the smaller drill or for any other reasons (concentricity, finish, etc)
Thanks
Jordan





RE: Drilling Multiple Diameters.
... That's how I'd program it for CNC, to maximize metal removal rate, and not expend any effort or time drilling through material that I was going to remove later anyway.
However, when I work on a lathe by hand, I almost never do it that way; I start with the small hole and work up to the larger ones.
Mike Halloran
Pembroke Pines, FL, USA
RE: Drilling Multiple Diameters.
RE: Drilling Multiple Diameters.
Mike, this is opposite to how I would have done it, trying to reduce how much force that I need to push the drills through, but that is like you said the manual way of thinking and your logic makes complete sense as well. I have made parts manually, and ran CNC's for a long time and now I am taking a hand at programming CNC's. Thanks for the input.
Jordan
RE: Drilling Multiple Diameters.
RE: Drilling Multiple Diameters.
Look at each application and choose you method but then be willing to change if problems occur.
RE: Drilling Multiple Diameters.
Thanks Bill
Jordan
RE: Drilling Multiple Diameters.
RE: Drilling Multiple Diameters.
RE: Drilling Multiple Diameters.
Again, I didnt have a specific part in mind but tolerances usually run from about .002 to .010 total depending on the part. So not overly tight, some more than others.
That was also my train of thought using 1 centre drill for the first drill and none after that. But wouldnt this work both ways?
Big drill first and you have the existing drill point to use.
Small drill first and you have the existing hole to use.
That is of course if the first drill was not wandering.
Thanks
Jordan
RE: Drilling Multiple Diameters.
RE: Drilling Multiple Diameters.