small hole drilling

[balnh]

i have to drill 200, .06 holes in AL, 2.45 in deep through. any suggestions on tool peck- chip load would be helpful. HSS tools and RPM maxes out at 6500. Tried peck of Q.07 S6500 F5. and broke pilot drill after 5 holes. Cut in half and took 30 mins to drill 35 1.00 deep pilot holes. is there an easier way

[edmBosto]

A TiN (titanium nitride) drill would help.

I believe you want a twist drill point that has a 118-degree geometry. It’s a good all-around bit for making holes in mild steel and aluminum.

 

A TiN coating makes the bit’s surface harder and gives it a slick surface for easy chip removal. It has a distinctive gold color. TiN twist-drill bits can drill at higher speeds and heavier feeds and work well in most metals

 

 

Did you look in the machinest handbook for some ideas?

Your could also have a lubricant situation if your just using coolant. You ever try kerosene?

 

At first I was thinking colbalt drills but..

Cobalt bits have a thicker web, increasing the drilling thrust needed to make a hole.

HSS are good for drilling in iron and steel but not for drilling softer metals.

 

As far as chip load per tooth? Maybe .002

[CNC-ERIC]

use short drill bit drill first.

then use long TiN drill peck drill, Q around 0.04, feedrate around 0.0006.

 

I did two holes around 1.75", no broken

[billystein]

i think at that feed you are wrapping thin chips around your drill. keep increasing the feed until you get the chips to clear the drill and drop the peck to .03 the chips should fly away from the drill.

good luck

 

 

billy

[Leigh @ Kodiak]

I would go 6500RPM, 8.5 IPM feed, and a peck of .025". To speed things up, you can change the clearance distace the drill rapids too after each peck. Some machines it's controlled by a parameter, some it's done by a value in the canned cycle. If the drill is making a rapid move to .1" away after every peck, that is a HUGE time killer, especially when you have alot of holes, and want to use a short peck distance.

[balnh]

Thanks for replys. Ithought about parameter to change peck clearance but i just wanted to prove progam out. ran overnight with .06 pilot and .06 ext drill 6 hrs for for holes. Machine is supermax with counterweight on z so peck drilling with small peck values arent exactly quick.

[Rick Henrickson The Boeing Co.]

mitsubishi MZS drill with pilot drill