Aluminum Roughing End Mill: Recommendations?

[wildo]

I have a few ZrN coated, high helix (45*), 3 flute end mills that are exceptionally free cutting in aluminum. There is a clear difference between these and my ALTiN coated end mills. So I figured that the ZrN coating would be the way to go for aluminum/titanium roughing. I was searching around and found this guy which looks pretty nice:

ZrN Coated 1/2 dia 3 Flute High Helix Carbide Rougher X 2.0 loc MariTool

www.maritool.com

But then I started researching a bit more and discovered the TaC coating. These guys claim as much as 20 times tool life in 6061 with no aluminum build up on the tool. That's beyond interesting. I found this end mill which states that it's for HEM, so I'm not sure it's as useful in a manual Bridgeport type mill. But it does have an aggressive chip breaker and might work nice as a roughing end mill for aluminum:

IMCO | Product Search

www.imcousa.com

I did notice that Niagara Cutter only lists end mills coated with TiCN for aluminum work. It's interesting to me that I can't find any ZrN end mills from Niagara, but perhaps I'm reading too much into that?

Thoughts?

 

[mikey]

Gotta' try one of those someday.

Niagara has those wavy tooth cutters but not recommended for aluminum. Big bucks so I'll wait until I have the need.

 

[wildo]

I also found this one via PM- it seems that Lakeshore Carbide is recommended over there when folks are asking about variable pitch aluminum specific end mill:

rougher/finisher variable flute end mill for aluminum

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www.lakeshorecarbide.com

Looking at the speeds & feeds chart for this end mill, they call for 200-2000 SFM, and .006 IPT. I put those values into a calculator and get these results:

200 SFM @ 1/2" Diameter = 1528 rpm
2000 SFM @ 1/2" Diameter = 15279 rpm

My max mill spindle speed: 2600 rpm, so:
Max SFM for my mill: 340 SFM

2600 rpm x .006 ipt x 3 teeth = 46.8 ipm, or .78 inches per second.

Basically- assuming 1D for profiling, and .5D for slotting- I can't push that rougher to failure. What a beast!! Seems like I found what I was looking for!

 

[mikey]

Let us know how it works out, Willy. Now you just have to hope your mill is rigid enough to handle what you're going to throw at it!

 

[wildo]

Let us know how it works out, Willy. Now you just have to hope your mill is rigid enough to handle what you're going to throw at it!

Will do. I ordered both the Maritools corncob rougher and the Lakeshore Carbide rougher/finisher. (I have a lot of aluminum work coming up in future projects)

 

[pstemari]

...
I did notice that Niagara Cutter only lists end mills coated with TiCN for aluminum work. It's interesting to me that I can't find any ZrN end mills from Niagara, but perhaps I'm reading too much into that?

I've only seen ZrN available on carbide tools, although Niagara appears to be moving away from HSS. Niagara also cut back substantially on its coating options: as I recall they dropped TiN entirely and are recommending AlTiN for steel and TiCN for aluminum.

My understanding is that TiN, TiAlN, and AlTiN are not suitable for cutting aluminum, especially the TiAlN & AlTiN. The problem as I recall is that aluminum chips will happily weld themselves to all of those coatings even faster than they weld to bright uncoated endmills.

 

[petertha]

I'm no expert & certainly not production oriented but I do favor uncoated for aluminum, particularly 6061 which is stickier over 2xxx and 7xxx.
Mine are different brand but this website is kind of a nice pick & choose categorization. The roughers are so much better for hogging material & they make nice almost granular chips. Just seems easier on everything, part stability & the mill itself. I really noticed this on my lighter RF-45 mill where you just dont have the same mass & power as a Bridgeport style. Finishing wise, these helix style do a nice job & just seem to cut effectively. They make a different chip than conventional EMs (and btw are the nastiest daggers to embed in your skin). Good luck!

https://www.the-carbide-end-mill-st...fine-pitch-for-aluminum-3-flute/uncoated.html

 

[wildo]

It’s super interesting to me that a few of you recommend uncoated EMs. I’m a beginner and haven’t tried bright end mills and that’s mostly because everything I read about ZrN coating indicates it’s a better surface for aluminum. Do you guys disagree??

 

[ddickey]

SPT Suncoast Precision Tools is running a sale on 3 flute cutters for aluminum.

 

[ChrisAttebery]

Is this for a manual 2-3hp milling machine? If so, I think you'd be better off spending $17 on a good HSS end mill such as this one:

http://www.yg1usa.com/feature/item_...d=1&sub_sub_id=37&pre=STANDARD&pre2=&name=HSS

I'd start it at 2600 rpm, 1" DOC, .25" WOC, 16" IPM (.003" IPT).

Here's a $37 cobalt 3 flute rougher that would also be a good match for your machine:
http://www.yg1usa.com/feature/item_...&sub_sub_id=88&pre=STANDARD&pre2=&name=COBALT

I'd start this one at 2600 rpm, 1" DOC, .25" WOC, 21" IPM (.0027" IPT).

With either end mill above, increase the feed up in steps up to .006" IPT. I'd bet that you'll find the machine's limits before you find the end mill's limits.

Carbide and the fancy coatings are for the guys with high hp high rpm CNC machines. If you're running into chips sticking to the end mills I'd recommend building or buying a mist type coolant system.

For reference, I have a G0704 that's converted to CNC. 1100W motor, 6750 rpm belt drive. I use the 3/8" version of the 2 flute above. 6000rpm, 60 IPM, .5" DOC, .04" WOC. I can run it harder, but this setup will run reliably for hours.