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

[escapethewrmhole]

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

Only if you haven't tried DLC.

I have been having incredible success with either these OSG products:

A Brand AE-VTS-N​

A Brand AE-TL-N
The VTS is the "premium" line and comes at roughly double the price of the TL.​

 

[crossthread82]

Only if you haven't tried DLC.

I have been having incredible success with either these OSG products:

A Brand AE-VTS-N​

A Brand AE-TL-N​

The VTS is the "premium" line and comes at roughly double the price of the TL.​

Can confirm DLC is the best IMO for aluminum, roughing or finishing. I've been having really good luck running GWS alumigators with their DLC coating, I also get my Mitsubishi AXD inserts in the DLC coated version and they last forever.

 

[plastikdreams]

Honestly I haven't tried either.

 

[Mtndew]

yes that was my other option of ordering new end mills in a 2 flute, had a regular coated 2 flute but seen the aluminum sheen on it after one part and BUE was bad on it. cut with more chatter then i was liking overall and had to drop rpms down to about 2200 and 8 or so ipm.
had my tooling rep in and he was going to ask a local shop what they had been doing, said they were running dry on aluminum but wasn't sure what grade.

What is the max rpm for your mill? A 3/8 end mill in aluminum running at 2200 rpm is extremely slow.

 

[BT Fabrication]

What is the max rpm for your mill? A 3/8 end mill in aluminum running at 2200 rpm is extremely slow.

10K, just had issues with it vibrating the part in the slot, is why its so slow. its about 50% of recommended rpms and was playing around with ipm from 8 - 19, fastest it liked was about 12.5

 

[BT Fabrication]

YG alupower 3 flute 37 degree helix diamond coated carbide endmills are where the money is at.
Use WD-40 mist if you cant run flood
even standing there with a spray can of WD-40 will be way better than running dry

I will have to try the WD and see if it makes a difference. hopefully it doesn't stain aluminum like some coolants i have used.

 

[plastikdreams]

Have you tried a ramping cut...you can fly through it then do a full depth cleaning pass.

 

[BT Fabrication]

currently is ramping in at 2 degrees. and step down about 0.100" and thinking of increasing that ramp slot axial feed to 0.150" or so to see if it will make a better chip as I think its loading up the bottom of the tool from possibly rubbing.

 

[hi-fly-cnc]

My learning curve was coming from a little aluminium extrusion router to a Brother S700 with flood cooling. It's night and day what some coolant will do for the cut quality and time end mills last! YG1 fancy end mills on the router would struggle to last an hour or so of cutting, even with tiny step overs. Forget deep cuts, they would typically fail instantly.

Just learned this lesson again yesterday, see:
https://www.instagram.com/p/Chw4rvYjOLT/
I was milling 1.5mm 6061 flat sheet. I milled some hundred or so parts, then turned off the coolant for a second to check the cut, and it made some rude noises. Then NEXT plate, it did that... Friction welded its way into the plate...

Cleaned it out, back in action and it did another 100+ plates without trouble. Lesson learned, beware turning off the coolant on more aggressive cuts

However! I also noticed that the very first hole it cuts on each part sounded terrible compared with the next 6 holes. On looking, the coolant doesn't switch on before the tool hits the part for the first hole (Speedios are fast...). Added a short pause before entering the cut and now all cuts sound the same. Massive difference from adding coolant!!

Anyway, that's my personal journey into learning the importance of coolant! (I'm no expert, new machinist, just learning on the job).

If I had to do your cut without coolant, then I would estimate the outside cuts would work ok, but slotting would have zero chance of success long term and I would expect chip welding every few parts... I would take a much smaller end mill and try a trochoidal path into it, with light cuts and lots of air blast. OR, slot down, but taking really shallow cuts with each pass?

 

[DavidScott]

On looking, the coolant doesn't switch on before the tool hits the part for the first hole (Speedios are fast...).

Are you turning your coolant off before the tool change with an M9? If so, don't. My coolant is on the tool halfway between the tool change height and the part if I let the machine deal with the coolant off and on for tool changes.

To the OP, If you are not using coolant then pretend you are machining 55 HRC steel instead of aluminum. Do not bury the tool, try to only cut with the side of the tool, use a good coating as they are well worth the money, only new end mills and if their performance starts to degrade then retire them until you get coolant. My go to end mills are Destiny Vipers with the stealth coating when cutting dry, but then I haven't done this enough to really try anything else. The Vipers are pretty free cutting so I doubt you will find better. You can order them direct here.

Adding WD40 or coolant while machining really helps a lot, but I never dick around with it when doing any production dry, as long as I am just milling. Just modify your program until you get it to work.