aluminum end mill, wet or dry? what coating? what supplier?

[BT Fabrication]

So been having an issue ramping down cut into aluminum, and in the corners it occasionally chips a tooth at the end of a 1/2" wide slot.
running it dry and just air blast.
What does everyone else use for coatings, coolant or no coolant, specific brands of end mills that have worked well.?

the slot is just a through slot in 1/2" thick aluminum and ramping spiral slotting in a 1" long slot x 1/2" wide, just wondering if my angle (2 degrees)into the material wasn't deep enough as it was trying to roll aluminum in front of the cutter. was getting vibration at higher speeds, so i was running it at 3000rpm which might be a little fast for the 18.8 IPM and about 0.0032 per tooth 3/8" 3 flute uncoated
im thinking it might be rubbing a bit, but not 100% sure.
endmill specs were about 5600rpm at 37.6IPM in slotting.
only thing I know was that at 3300 RPM it was worse and increasing feed didn't help.
next thing i can think is drop rpms lower to get a thicker chip

 

[apoet]

Use flood coolant if you have it. I'm assuming you are using a carbide tool, so coating really shouldn't matter. Is the setup rigid? I'd turn the rpm way up. Your ~.003 chipload seems reasonable to me, along with your ramp angle

 

[plastikdreams]

ZrN seems to be all the rage for aluminum coatings these days.

 

[Finegrain]

So been having an issue ramping down cut into aluminum, and in the corners it occasionally chips a tooth at the end of a 1/2" wide slot.
running it dry and just air blast.
What does everyone else use for coatings, coolant or no coolant, specific brands of end mills that have worked well.?

the slot is just a through slot in 1/2" thick aluminum and ramping spiral slotting in a 1" long slot x 1/2" wide, just wondering if my angle (2 degrees)into the material wasn't deep enough as it was trying to roll aluminum in front of the cutter. was getting vibration at higher speeds, so i was running it at 3000rpm which might be a little fast for the 18.8 IPM and about 0.0032 per tooth 3/8" 3 flute uncoated
im thinking it might be rubbing a bit, but not 100% sure.
endmill specs were about 5600rpm at 37.6IPM in slotting.
only thing I know was that at 3300 RPM it was worse and increasing feed didn't help.
next thing i can think is drop rpms lower to get a thicker chip

No coating for finisher.
ZrN, or Destiny's "Stealth", or nothing, for roughers.
Definitely coolant, lots and lots of coolant. Firehose stream right into the cut if possible.

Without coolant, I think you are going to fight BUE and completely clogged flutes, even with a good coating.

Regards.

Mike

 

[wheelieking71]

Coolant is pretty much mandatory in Aluminum.
What machine? How rigid is the set-up?
I probably wouldn't even ramp that. Just plunge straight through, rough, finish. All same tool.

 

[Mtndew]

If it's 7075 aluminum, then you can get away with no coolant for the most part since it's harder than 6061.
But for 6061 I always use coolant, period.
As for chipping the end mill corners, it could be a couple of different factors really.
3000 rpm and 18.8 ipm is .002" ipt which seems ok, but I would double or even triple the rpm's if you can.
Typically we use bright finish end mills for aluminum. And if you're having chipping issues on a thru slot you can either use a bullnose or use a drill for a start hole then plunge into the hole and slot away.

As for the 2 degree ramp, the 3 flute should be capable of a much larger ramp angle. Heck you can even plunge with it.

 

[empower]

yep some people are lazy now a days............ ok most and don't help themselves first.

the internet is more then just "adult" entertainment, there is actual information available here also!

for the lolz

 

[plastikdreams]

for the lolz

Is that really necessary?

 

[empower]

Is that really necessary?

was his post really necessary?

 

[BT Fabrication]

Use flood coolant if you have it. I'm assuming you are using a carbide tool, so coating really shouldn't matter. Is the setup rigid? I'd turn the rpm way up. Your ~.003 chipload seems reasonable to me, along with your ramp angle

I have coolant, but not yet setup on this machine I just got. Had to fix a few things on it first before adding coolant and parts don't show till november...

 

[plastikdreams]

was his post really necessary?

Do you mean this thread?

 

[BT Fabrication]

If it's 7075 aluminum, then you can get away with no coolant for the most part since it's harder than 6061.
But for 6061 I always use coolant, period.
As for chipping the end mill corners, it could be a couple of different factors really.
3000 rpm and 18.8 ipm is .002" ipt which seems ok, but I would double or even triple the rpm's if you can.
Typically we use bright finish end mills for aluminum. And if you're having chipping issues on a thru slot you can either use a bullnose or use a drill for a start hole then plunge into the hole and slot away.

As for the 2 degree ramp, the 3 flute should be capable of a much larger ramp angle. Heck you can even plunge with it.

yep its just 6061.
tried to increase it to 4000 and just destroyed it even faster on the first step down.
its a bright polished end mill and 45 degree helix and sharp corner, might switch to a 0.030rad if i can.
had it plunge at first, ya got about half way, clogged up and snapped it off in the holder.

 

[empower]

Do you mean this thread?

no, the post i quoted.

 

[plastikdreams]

no, the post i quoted.

That's from a different thread and has nothing to do with this one other than to start shit.

 

[BT Fabrication]

for the lolz

ive scoured the web from a ton of suppliers, all the way from maritool,yg, iscar, widin etc to any information/research or articles. i could find from tooling suppliers. so not like i haven't tried. not really wanting to keep breaking $50+ endmills off when it could be something simple I'm overlooking. the breakage isn't consistent either.

 

[Finegrain]

ive scoured the web from a ton of suppliers, all the way from maritool,yg, iscar, widin etc to any information/research or articles. i could find from tooling suppliers. so not like i haven't tried. not really wanting to keep breaking $50+ endmills off when it could be something simple I'm overlooking. the breakage isn't consistent either.

Coolant. You have to use coolant. Otherwise the flutes will clog up and the tool will snap.

 

[empower]

That's from a different thread and has nothing to do with this one other than to start shit.

thats a very astute observation! you are correct. just like his post had NOTHING to do with my thread other than starting shit.

 

[plastikdreams]

This isn't the who can do one better forum

 

[empower]

This isn't the who can do one better forum

just striving for equal treatment for everyone

 

[Mtndew]

not really wanting to keep breaking $50+ endmills off when it could be something simple I'm overlooking

How much is the tool sticking out from the holder? And is it chattering?
Even dry it shouldn't be chipping the edges unless you're getting edge buildup.