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Indexable drill in aluminum

bdog123

Plastic
Joined
Aug 9, 2022
I am running into problems with my 1.5" indexable drill. The machine i am running the part on is a okuma genos L3000 (lathe).The parameters that I am currently running is RPM 1100, Feed .002" per rev and pecks at 1.0".
The drill is cutting oversize by .02", what could be causing this issue. The surface finish looks similar to sheep wool. Also the tool has thru coolant.

Any subjections would help
 
Without knowing the brand/style and insert I would still say 450 SFM seems very low for aluminum and you should probably be 2-3 times higher unless you can only spin the part to 1100. Also .002" per rev seems really low at that size and should probably be .005-.01" per if not double that and with thru coolant you should be able to avoid pecking. As for cutting oversize, is the drill pocket swept in properly and is the turret properly aligned?
 
Did you try comp'ing the X offset down .020?

How deep yuh going - pecking at 1"?
Are you git'n stringers - since you are pecking?
If not, you shouldn't need to peck.

???

Surface finish?
That's a roughing application. You can come back and take another stab at it for clean-up if you want.

Alum likes it's oil!
Don't skimp on coolant % for deep drilling in alum.


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Think Snow Eh!
Ox
 
Why would i want to compensate the drill to cut off center? I'm going to sweep the holder tomorrow to ensure its cutting on center.
 
Define exactly what kind of "indexable" drill that you have.
(since you are asking about comping X)

Does this tool have a pair of trigon or similar inserts?
Or does it have one replaceable drill tip?

At 1.5" I ass_u_me it to be the trigon type, and if that is the case, you should be able to comp it in closer than that, because one insert IS (and is s'posed to be) acting as a boring bar.

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Think Snow Eh!
Ox
 
Comp X .020.
It will either git bigger or smaller, depending on how you have it in there.

If you are hoping to have a fine finish and on size, then you may need to drop down one size and take 2 passes at it.

But it is possible that you may be able to drill -.020 with this one and then take that second pass at it.


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Think Snow Eh!
Ox
 
I appreciate all of the responses. Will give another go at it tomorrow. I'll try comping the tool first.
 
.002" is definitely too light. Also make sure everything is TIGHT. any looseness, flex or machine wear will show up on insert drills. Another question, do you have aluminum inserts in it? Insert shouldn't make that big of difference on diameter, but can definitely affect finish.

Any info or pictures you can give us will make a big difference on the quality of help you get around here.
 
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The specs for that drill say you should be spinning it twice as fast and feeding three times harder. Your low surface footage is going to contribute to the poor finish, and since your feeding it too light that's more than likely why you are needing to peck; which shouldn't be the case with an insert drill.

And like others have said comp the drill, granted most insert drills I've used generally do drill big, however if your x axis center is off you're "boring" the hole bigger with the drill while its drilling.
 
The parameters that I am currently running is RPM 1100, Feed .002" per rev and pecks at 1.0".

Per the link you shared, you should be at 1100 SFPM, and .007" ipr. NO PECK.
That's 2801rpm, you're going 1100rpm. Let the big dog eat!
 
We had a size issue on our lb3000 the tool holder not being dialed in straight from front to back. If the holder is out just .001.
Project that out to the drill tip, of course that was the last place we checked. That is one feature I sometimes do not care for.
 
As said, too low sfm and feed. And maybe poor insert choice.

Another thing to check an indexable drill will really perform poorly if it's above or below center. MDI to hole center and manually drill until you get full diameter. Take a look at the center. If no tit may be too high. If big tit too low. A small tit .005 or .010 dia is fine.

We've had smaller drills bent too high or low and they really suck. Bad finish and sound atrocious.
 
I am running into problems with my 1.5" indexable drill. The machine i am running the part on is a okuma genos L3000 (lathe).The parameters that I am currently running is RPM 1100, Feed .002" per rev and pecks at 1.0".
The drill is cutting oversize by .02", what could be causing this issue. The surface finish looks similar to sheep wool. Also the tool has thru coolant.

Any subjections would help
I'd boost that RPM by a bit, and the feed to .004" per rev.
I'd avoid pecking, and make sure sufficient coolant is making it through.
You may also want to indicate the tool holder, just to be sure.
 
I'm runnin a 1.5"Ø insert drill in Ali right now.................Kennametal DFT style..........2800 rippems at .008"/rev 3.75" deep. Keep the coolant flowin' and keep it juicy(mix it a bit on the thick side)................................
 
I run my 1-7/8" insert drill in 6061 almost daily. Through coolant S2500 F.015. I stopped trying to keep track of insert life because it was less $0.01 per day. Biggest limitation will be spindle HP
 








 
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