Small holes in aluminum


I will be working on some T60-61 aluminum plates, about 40" X 27" X 2.5"
with all kind of pockets from one side leaving 0.25" thick plate.
There will be 40000 holes drilled thru that 0.25".
0.1" dia.
Just wanted to pick some brains and see if someone has experience with this
kind of work.
I figured 15" per minute at 7500 rpm and 2 to 3 0.003" chip brakes per
hole.
I just hope this will not wrap any chips around the drill because the plan
is to let it run thru night as spotting and drilling will take way more than
a day.
Any suggestions?
Jerry
Reply to
Jerry
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Pecking sucks! With the right drill & feed curling chips shouldn't be a problem,
You will probably do the drilling from the same side as the pockets? It just *might* be better to face the hassle of turning the part over and drill from the back. Better flush of chips this way, and you can use a stub drill and skip spotting.
Reply to
J. Nielsen
I can't drill from the same side as pockets as it would be 2.25" deep and some of the holes are almost in line with edge of the ribs. Any recommendation on drills and are my speeds and feeds in the ballpark? Jerry
Reply to
Jerry
Consider a multiple spindle head for the machine and act as if it were only 20,000 or 10,000 (or maybe less) holes?
I know a good source...
Regards, Joe Agro, Jr. (800) 871-5022 01.908.542.0244 Automatic / Pneumatic Drills:
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Spindle Drills:
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Tapping:
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Site:
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V8013-R
Reply to
Joe AutoDrill
Seems like a good laser drilling job, possibility may be less expensive to job it out for the drilling.
Reply to
noneya
I'd get a good parabolic flute drill and go through in one shot, no pecks
Best, Steve
Reply to
Garlicdude
And at 100 IPM. I've drilled 304L at 10X dia. with no peck in a hole that size at 22 IPM and 2K.
Reply to
John R. Carroll
"Jerry" wrote in news:fKaOn.27292$ snipped-for-privacy@newsfe20.iad:
Ostrum Dib2 coated drill, how many RPM you got?
I run 2.0-3.5 mm drills up to 10xD at 10k RPM and 3200 mm/min feed (125"/min), single shot-no peck. Guhring parabolic uncoated carbide drills will work the same, just won't last as long. (100,000 holes for the Guhring vs. 1 million or so for the coated ostrum - in 14-16% Si Aluminum alloy).
Reply to
Anthony
I have 10000 rpm max. Outsourcing is not an option. I'm not at home for the weekend so I can only view this using usnet but thanks for all the replies. I will try to get the drills you recommend. Jerry
Reply to
jerry
Do you HAVE to spot? How are you deburring the exit? If you have to chamfer/deburr the hole then maybe drill thru and follow up with easy burr tool that will chamfer and deburr both ends with one quick shot.
Reply to
noneya
Antony, did you really mean 125"/ min? Where do you get those drills? I'm hoping to drill it without spotting as even at 2 seconds per hole, 40000 holes means 12 hours per part. The whole part has to stay flat within 0.002" so I will have to take very small cut of both faces after drilling. If i use really sharp tool it may leave sharp edges but without a burr. Jerry
Reply to
jerry
A grinding shop can easily modify a drill to put a chamfer on the hole.
Reply to
J. Nielsen
wouldn't a center cutting high helix endmill work more reliably in this situation ? I'd be worried about the flutes getting packed up and causing the hole to go non-round and oversize-
Reply to
raamman
I found Guhring drills online but I can't seem to find Ostrum. Does anyone have a link for a supplier? Jerry
Reply to
Jerry
"Jerry" wrote in news:fKaOn.27292$ snipped-for-privacy@newsfe20.iad:
Crazy Drill Alu -
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$file/CrazyDrill%20Alu_en.pdf You can feed 60 IPM at 7,500 rpm. You can run higher rpm if the machine has it.
Don't feed this drill slower or it will break. Don't use it in anything ther than aluminum or it will break.
Reply to
D Murphy
Thanks, I'll check it out. Jerry
Reply to
Jerry
Use an endmill. Do chipbreak pecs every .010, retracting back .020. Clear the endmill leaving .03 approx of flutes. Clear the flutes by .02/side. Turn the flush up high, the rapid and rpm all the way up, feed like a madman. This will run all night no problem (if it makes it thru the first hole)
Reply to
vinny
that many pecks per hole ( 26 x 40 000 holes ) will take forever, maybe you meant every .100" ( 3 pecks per hole ) ?
Reply to
raamman
As I pointed out 2 seconds per hole is 12 hours so if I use endmill and peck it will take a week or so. Jerry
Reply to
Jerry
- Hide quoted text -
you might be able to do a one shot mill through with a ballnose.... (I just can't get along with drills)
Reply to
raamman

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