recommended end mills for aluminum

[Marshal]

We've been having some issues lately with getting nasty burrs on everything we cut (aluminum, 6061 or 2024). Our machinist has been using the TICN coated carbide end mills, usually 3-flute and 45 degree, and they've been leaving a nasty burr compared to using a 30-degree 3-flute standard carbide cutter, which wasn't leaving a burr at all. On the one we're taking about a 0.100" depth of cut using the whole diameter of the cutter, but there's a 0.005" finish pass at the end. Similar situation with the other one today, which is a 0.025" depth cut with a 0.003" finish pass at the end.

 

I don't know if we changed the speeds and feeds much when we switched tools, but I just figured I'd ask here and see what your thoughts were.

 

On a side note, what kind of speeds and feeds should we be running at with aluminum like this? Without too much of a machining background, the cutting formulas don't make a ton of sense to me, especially if I don't know what kind of chip size/load is best.

 

Thanks in advance for helping out this noob

[Rstewart]

My favorite are the SGS S-Carb 3 flute endmills. You can really Haul with these roughing, and then come back with a slower finishing pass.

[neurosis]

I have been running the sgs S-carbs too. They are great. We took one in on a test about four months ago and it is still running in the machine right now. I cant tell you how much material this thing has removed. We use it "ONLY" for roughing however. I am sure that if we were trying to use it as a finisher it would not be pretty at this point.

[Marshal]

My favorite are the SGS S-Carb 3 flute endmills. You can really Haul with these roughing, and then come back with a slower finishing pass.

 

define "really haul" lol

[Rstewart]

About as fast as you wanna go, if ya got tha RPM's I haven't broken one yet (at least a year of using them).

[Marshal]

About as fast as you wanna go, if ya got tha RPM's I haven't broken one yet (at least a year of using them).

 

we've got 8000RPM max. I'm looking for the "right" speed/feed for these operations. Maybe we're running these 45 degree helix cutters too slow, and that's why they're kicking up a burr while the 30 degree ones aren't?

[Chris Rizzo]

I prefer just a high-polish hi-rake solid carbide 3 flute. Like the sgs's or maford 138 series. Plowing full width will give you that burr alright. Leave more for a finish pass maybe, make sure your climb milling. 8000rpm, ahhh somewhere between 50-100imp. :/

[Mr. Wizzard]

Onsrud end mills work great for me. I've found they have the best selection for corner radius and necked length end mills and they cut awesome.

I only have 6k spindles for the little Haas TM-1 and TM-2 here, but 6061 with a 3/4 cutter x 1.625 FL can go 6k, 85-100 ipm, .125 deep, .375 wide.

Using 2-d highspeed toolpaths, i can go .030 stepover, 1.500 deep, 6k, 85-100ipm, but that keeps the spindle load @ around 100%.

[Marshal]

I prefer just a high-polish hi-rake solid carbide 3 flute. Like the sgs's or maford 138 series. Plowing full width will give you that burr alright. Leave more for a finish pass maybe, make sure your climb milling. 8000rpm, ahhh somewhere between 50-100imp. :/

 

So right now we're running that 1/2" at 5000RPM, 45ipm, 0.100" depth. You're saying we should at least up the RPM's? I've been trying to work on dropping our cycle times as much as possible, a little bit at a time, so any improvement helps.

 

The big question that I haven't really gotten an answer on is whether the helix angle makes a huge difference? Because that's the only real difference between the two endmills, the 45 gives a burr, and the 30 doesn't seem to.

[Justin Beebe at Folsom Tool]

Destiny Tool three flute "Viper"

[specv]

Look at Helical solutionss, we run 95% aluminum and they are the best for the money that I have seen, also niagara 3fl elites.

 

we run 1/2" dia, 14000 RPMs @ 250-350ipm

[machinedudester]

I use a Hanita 3/4" 3 flute variable pitch at 8400 rpm. 200 ipm .50" doc. I prefer polished uncoated solid carbide to TICN coated in aluminum.

[Dave.L]

We use a lot of Garr Alumistar coated endmills and they work very well.

 

For aluminum you should be at least 1000 SFM so for a 1/2" endmill that would be 7640 PRM. So, run the MAX RPM of your machine. I only run slower with long reach tools. For 1/2 endmills, we run 12K RPM all the time.

 

Feed is somewhat relative to your part geometry and machine dynamics.

 

The best info will be to use the manufactures recommended speeds and feeds per tool.

[Bob W.]

I really like the MA Ford 138 series. Here is a video I posted on Youtube. Stepovers are 25%

 

http://www.youtube.com/watch?v=kV0t4C4_bZ8

[BernieT]

Any of the coatings on carbide end mills aren't worth a plugged nickel on aluminum. Go with plain uncoated carbide.

 

 

Bob W - nice video!!

[35K chipper]

destiny for me!!!!!!!! 1/2 3flt 5/8 loc 30000rpm @ 1400 ipm................

 

 

35k

[Mic6]

1/2 3flt 5/8 loc 30000rpm @ 1400 ipm

yeaa yeaaa

 

I agree, Ticn is a ferrous cutting coating. If you MUST get coated get ZRn of Ti Diboride, otherwise go polished, high helix!

[shazam/TPP]

CGS Ferocious end mills, they're carbide hi-helix.

 

 

Ferocious

[MACHINEMASTERG]

I belive what rizzo said (leave more material on for the finish pass and climb mill)

it could be your ruffing passes burr is bigger then the material you left on for finishing

[Marshal]

I belive what rizzo said (leave more material on for the finish pass and climb mill)

it could be your ruffing passes burr is bigger then the material you left on for finishing

 

Hopefully I can get our stubborn machinist to try this, but I doubt it

 

So the high helix should actually be better for aluminum? And the coating isn't so good for running lighter loads like we usually do?

[Bruce Caulley]

Sounds like the tools you are using are more for stainless. Garr 842M series and IscarEB3??? are high helix polished and would be a better bet.

 

Bruce

[Marshal]

Sounds like the tools you are using are more for stainless. Garr 842M series and IscarEB3??? are high helix polished and would be a better bet.

 

Bruce

 

I dunno, they say right in the catalog they're specially designed for aluminum. That's why he bought them lol

 

He made the finish pass bigger, but it's still leaving the same size burr as before. Which leads us to believe it has little or nothing to do with the finish pass. Our machinist is convinced it has everything to do with the helix angle of the cutter, could there be any truth to that?

[35K chipper]

Marshal,

 

Questions for you.

 

tool holder what type? (shrink, hydraulic, collet, or set screw)

 

spindle bearing condition?

 

machine age?

 

the reason i ask is the difference you saw between 30 & 45 helix angle could be a spindle bearing problem.

 

only three coatings i use on aluminum viper stealth , zirconium , and amorfic diamond , or uncoated polished carbide.

 

35k

[Marshal]

Marshal,

 

Questions for you.

 

tool holder what type? (shrink, hydraulic, collet, or set screw)

 

spindle bearing condition?

 

machine age?

 

the reason i ask is the difference you saw between 30 & 45 helix angle could be a spindle bearing problem.

 

only three coatings i use on aluminum viper stealth , zirconium , and amorfic diamond , or uncoated polished carbide.

 

35k

 

We're using collet holders. Spindle bearings "should" be fine. The machine's (Hurco VM1) around 2 years old, maybe 3.

[SKIR68]

EUREKA !

The machine's (Hurco VM1)

"Houston we have a problem here..."

sorry, i couldnt resist, we have several Hurcos here as well, not bad cnc machines, just not very rigid for applying HSM techniques.(IMHO)

We make alot of aluminum parts as well, I like to use DataFlute brand 3fl. emills. They work well with no coating !! For HSM we will setup on machines with much higher spindle speeds, and actually have the HSM option.