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New to turning aluminum, tips?

Tupper87

Plastic
Joined
Feb 12, 2019
Hey everyone. So normally I machine a lot of exotic materials such as titanium, custom 455, inconel 718 and various super alloys which all seem like second nature to me; however, now im turning aluminum. What in the fuck? I did my test program with coated carbide and the finish was pretty good on a ID bore. Now when I switched to the uncoated tool, its fucking terrible... what gives?
 
You're seriously going to ask this question without posting your current Feeds and Speeds?

NOTICE TO ALL NEWBS!!!! Post a question here, WITH S&F, and the Machine designation, and the controller and the model of controller. Good Lord,

R
 
You're seriously going to ask this question without posting your current Feeds and Speeds?

NOTICE TO ALL NEWBS!!!! Post a question here, WITH S&F, and the Machine designation, and the controller and the model of controller. Good Lord,

R

ISCAR CCGT 2-0-AS IC20, 2000 sfm, .0078 rad, .00035 ipr, doc .01". Fanuc control on a nakamura tome wt-150II.
 
Surface finish req is .4um.
That's really a honed or ground finish. Imo, you are asking for more than what's realistic on a lathe. You might be able to use a larger rad and bump up the feed, 3 tenths is so light it's just scuffing the surface.

If you were getting good results with your other insert, switch back. But I would question if it was really a 16 finish. I consider a 32 the best I can reasonably expect from a lathe.

I'd agree with Rob, increase your finish allowance. Try to get the string feeding out of the hole smoothly. If it wraps around the bar you are f'ed.
 
That's really a honed or ground finish. Imo, you are asking for more than what's realistic on a lathe. You might be able to use a larger rad and bump up the feed, 3 tenths is so light it's just scuffing the surface.

If you were getting good results with your other insert, switch back. But I would question if it was really a 16 finish. I consider a 32 the best I can reasonably expect from a lathe.

I'd agree with Rob, increase your finish allowance. Try to get the string feeding out of the hole smoothly. If it wraps around the bar you are f'ed.
Fuck sakes to think I bought a new bar and inserts for this thinking it would improve and now I'm switching back... thanks for the advice guys.
 
I'll give that a try tomorrow. See if it improves anything. Any particular reason as to why the increase? Radius.

You're asking some deep metaphysical shit about Boring. Bars are Bars and they flex. Over all I have better luck Burying Bars in the cut, rather than dancing around the border of the limits.

r.0078" and a .01" DOC only leaves you .0022" over the TNR of the insert. IF that's the way the program is written. IF you are using G71 the U value in the first line expresses the DOC per the Radius of the PART. So a .01" DOC is going to take .02" off the Diameter. Which means to the Operator that the TNR is deeper than the DOC, which is good. I like to go double that, out of habit, out of redundancy, out of simplicity, out of stubbornness. Just my opinion, you get what you paid for it. But it's not going to ruin your day, either way.

R

I also agree with Conrad on the Finish. I have achieved an 8rm Finish with only a Turning Tool. But it wasn't easy.
 
I think you’re looking at a PCD insert, on the bright side if you don’t crash it it should last you quite a while.

Wind it up as fast as she’ll go you’ll probably break a chip too.
 
Fuck sakes to think I bought a new bar and inserts for this thinking it would improve and now I'm switching back... thanks for the advice guys.
What's the bore diameter? With a 1/4" IC, I'm imagining not a large bore or you'd be using a bigger bar?

If it's a 1" diameter you need over 7K to get 2000 sfm. Are you really getting that? What's the G50 rpm?

edit: just looked at that machine. Sporty! :)

Like these guys say, you can beat a 32 finish on a lathe. But it's not trivial, and it's easier to achieve on larger diameters and harder materials, and on OD's. If I have to deal with a 16 finish, I price it that way.
 
Doc is never diameter lol.

Sendt fra min EML-L29 med Tapatalk

You know that, I know that and litlerob knows that, but when trying to fix someone's problem we have to make sure we're all on the same page. Ever notice how they don't like to give us important information and just want an answer? That's why he asked that question ;)
 








 
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