Deep drilling question

[jeffescott]

I am drilling holes 3.2 mm dia and 17mm deep, 6061.   I have a pretty good flood.

It is working. But I am welding up the bits say every fifth hole.

Rpm is 24000 0.5mm pecks no dwell, full retract, plunge at 380 mm/min.  I am using a ball end mill, cause drills have been less successful.

Firstly is there a way to dwell at the top of the

peck? To help cooling and chip removal.

Secondly should  I drill 1/2 the hole then come back later to finish it.

If I speed up the plunge they weld up faster and every time.

Really need some good ideas.   I am getting really good at anodizing carbide bits out of holes.

[a.laasW8M6T · Accepted solution]

I wouldn't use a ballnose they aren't designed to drill holes

Drill bit should be fine, 17mm isn't deep at all.

24K rpm is waay to fast though, you should be somewhere around 9000rpm for a Drill that size.

keep the feed at 380mm, you could go a little higher

0.5mm peck is fine.

I was doing some actually deep holes today in Aluminum(80mm deep)

3200 rpm, 0.08mm/rev feed 0.75mm peck with flood coolant

[jeffescott]

Load it up tomorrow thanks a lot.

im also getting really good at tool changes.  One more won’t hurt

[jeffescott]

That works fantastically.

I choked up a lot on the drill bit....I always wonder whether that is the right thing to do, not sure if grabbing flutes is improving things???

Last time i tried a drill bit it was a pretty old one...that probably sent me off down the ball point rabbit hole.

[a.laasW8M6T · Accepted solution]

Do NOT chuck on the drill flutes, or the flutes of anything for that matter

that is extremely bad practice.

Less gripping force, more runout, less stability.

you should always chuck on a fully cylindrical portion of the tool shank.

[seth.madore]

---

@a.laasW8M6T wrote:

Do NOT chuck on the drill flutes, or the flutes of anything for that matter

that is extremely bad practice.

Less gripping force, more runout, less stability.

you should always chuck on a fully cylindrical portion of the tool shank.

---

I think this needs repeating for anyone else arriving in this thread.

[jeffescott]

Thanks for the instruction.  I was definitely leaning that way.    Learn something everyday