More fun with aluminum, 1/2" end mill, .012 per tooth.. dry

[exkenna]

So I'm at my buddy's shop Saturday morning and I tell him about a recent thread on this board about machining aluminum dry. He asks me what I think the upper limits are for doing this and glancing over at his pretty Doosan VMC I reply "Let's find out".

I knew I was gonna get beat up pretty bad shooting video from this angle so I fashioned a bandanna from shop rags, wore gloves, glasses, and yes.. even cut a hole in a garbage bag and wore it with pride.

Anyway, here is what .036 per rev with a 1/2" tool looks like. The tool could take more but the spindle was at 133%.

No wimpy chips.

YouTube - Destiny Viper End Mill Video

 

[fpworks]

Not bad, but I'd like to see how it does over a couple days worth of production.

And...tell him to pick up the pace on that 2" Ripper...that was painfully slow I know your tool will run at least 2-3 times that feed.

 

[DMF_TomB]

aluminum feed per tooth

with milling aluminum with an end mill
.
if end mill is short and depth of cut not too deep i usually start with
2 flute 0.005" per tooth 0.010" per rev
so cutter at 4000 rpm is 40 inch per minute feed.
.
been my experience cutting dry.
1) part warms up even 20 degree F and it will be cut perfectly at dimension at 90 degree F but as soon as it is cooled to 70 degree F it will be undersized. i have had that problem too many times from cutting aluminum dry.

2) dry end mill goes dull eventually and aluminum will stick to edge and failure is usually a big mess fairly quickly. too quick to see and stop it from damaging part usually.

3) extremely high feed can push a part right out of a vise and or lift / move it out of position. also high feed can push on aluminum so much as too bend it away from cutter and if you took same cut again you might find you will cut more metal as aluminum is bending back toward cutter. same thing happens on a lathe all the time. thats why many take 2 finishing cuts as it might take ahwile to get all the spring back out

4) a roughing end mill can chew up metal 2-10 faster than a regular end mill. but a finish pass after parts cools off with a finishing end mill is most of the time needed.

5) i heard the theories the heat goes into the chips. but if part is covered in hot chips than part will get hot.

6) most of the time if i damaged / destroyed a part pushing a dry end mill too hard my boss would be extremely pissed at my damaging a valuable part.

 

[Mickey_D]

I switched over to the Destiny Viper 3 flute mills about 2 months ago and they are AWSOME! On Friday I was running a half inch one at 7500 RPM full slotting width .55" DOC at 105IPM and it was happy as can be. I was running flood to help get the chips out.

 

[Billiam]

Destiny Vipers are decent, but not really any more special than countless other 2/3 flute, uncoated, AL-specific endmills. Any good endmill can cut dry for awhile... until it inevitably loads up and snaps.

0.012" is very high for a 1/2" EM, double what I'd be comfortable with running unattended. With that amount of tool pressure, the endmill can snap unexpectedly even if it doesn't load up.

 

[exkenna]

Not bad, but I'd like to see how it does over a couple days worth of production.

You know.. I wonder that myself.

We were just having fun trying to make the tool choke.
It didn't choke.

 

[Edster]

Lookin' good curtis! Destiny Vipers are working good over here too.

Just curious about the 50% radial stepover, thought it was better to run a 40% or 60% for the cutting edge engagement.

 

[358Mustang]

Crank up that 2"

 

[cbright]

2" needs more cow bell

I run my 2", 3 insert cutters much faster than that (wet). Of course it depends on the machine. My Okuma MB has a 30hp 15K spindle, so I run .300 depth of cut, 12500 RPM, 325 IPM. This machine doesnt care what the axial load is, even in a full channel, the spindle is super quiet, the spindle load runs around 60%. The only problem I have is that machine steams off about 50-75gallons of coolent per shift. It's fun to watch though.

 

[SteveinAZ]

cbright...Wow, that's 195 cubic inches a minute if you are running full width, not sure if that's the case as you have those statements in separate sentances. What manufacturer is that one? I would love to buy a cutter that can run that kind of MRR with ~18 HP - sign me up for a few of each in everything from 2" to 5" and a few hundred inserts! I sure hope you can get chips out of your machine well, cause that's a ton of chips to haul.

We ran a Destiny Diamondback rougher the other day dry by mistake...ooops! It was running 3.175" deep x 0.100" stepover, 14,500 rpm, 280 ipm, it pulled out of the milling chuck a little bit, so it scrapped the lot of parts, but never loaded up, never alarmed out on tool management load, just kept on chugging away. Still finished out at over 500 minutes of cutting before we retired it. That dry running was only about 25 minutes total, so not sure how it would have done over the course of the day, just pretty sure it would not be as slippery dry as wet.

Steve

 

[huskermcdoogle]

We have been running a 3/4 Diamondback DVH rougher for a few months now, havn't changed it... I am running 1.625" LOC .15" WOC 8000RPM and 400IPM so .0167clpt no coating on the tool. It takes these parameters all day long and makes short work of roughing out these parts. So far it has cut about 400 parts which would equate to roughly 40000 cu.in. removed so far, the load meter only shows an increase of 3% so far since day one. I don't plan on changing it. It continues to fill chip bins..../400. With rapid moves and tool change approach in account it runs a pretty steady 50 cuin/min average, which is definately no slouch on a part like this (too much hunting and seeking for material to ravage....)

+1 for destiny tools


Husker

 

[exkenna]

Tell the Nuccetelli's I said hi.