Have I just smoke blown where the sun don't shine

[terry5357]

I just had this new guy who has been programming for 15+ years, but has never run a machine, tell me that people are cutting still at 70 rockwell with a 1/2" carb end mill running 20,000 rpm.

I am old school and 20,000 rpm on a 1/2 inch cutter is over 2500 sfm. Have I been in the dark for so long that this is truly happening? also he stated that this was done in roughing operations,

high speed light cut (.05 depth). Am I an old fool or is he talking sh*t

[Hardmill]

70rc isnt out of the ballpark at all.

2500sfm is prolly a bit too fast though.

All depends on the tools they are using.

 

 

PEACE

[titanium neck]

I would not do that, but I would imagine that there are endmills that are capable of doing that, just not on my machines....or at least not with me standing there....

[terry5357]

I'm not saying that 70rc can't be cut. I just haven't seen many tools that the corners would hold up to such an incredibly high SFM. THis guy was talking like this was happening everywhere and was now the norm. Like I said, he is a software driver with no machining experience, thats the kind of person I start doubting the validity of their statements

[titanium neck]

My answer has nothing to do with passing judgement on your agedness or your level of foolishness as it applies to or in relationship to your age

[?Mark]

Terry, I'd say you're right in your assumption.

The guy if propably full of it

I've cut 62+ rc tool steels but I don't think I ever exceeded 1200 sfm and that was with cbn inserts...

 

Now, how often do you see 70 rc steel anyway

 

[MLS]

What tools can you get even close to that SFM with Hardmill?

 

We cut some steel, but usually about 1/4 of the SFM with a semi-conventional approach.

 

How do you cut it? Small stepdown?

 

I'd like to see that. *Ponders operator's reactoin

[Hardmill]

Believe me its doable, and yes theres lots of ppl at it.

Hes not blowing smoke

 

PEACE

[terry5357]

Ok so "yes it IS done. but! not very often and not the norm as he was descrbing it. So my assumption is correct ********...........LOL.

 

You just can't believe much of what a non machining programmer says........nothing against the ones that have their **** together and understand speeds, feeds and machining in the real world

[tonyc]

Look, The GUY has never run a machine so as far

 

as in concerd he Knows nothing about tools, feed,

 

rates and materials, go with your gut.Hes fool of

 

sh*t.

[Guest CNC Apps Guy 1]

62 is the hardest I've cut before, finishing with a CBN Ball E/M (me thinks... was a number of years ago) 1/4 Ball E/M 19,550 @92 IPM. So guess it's not out of the realm.

 

I'm not sure how long the corners would hold up though... guess it would depend on the tool material. Ceramic may hold at the SFM... I've turned HSS using Ceramic Inserts. Not sure what the hardness of HSS is but it's pretty darn hard.

 

I would not quite throw up the flag, but I'd certainly have it handy.

[Mcam Nut]

I would have to dissagree, imo he would of never made it that long programming if he didnt know s&f, doc, tooling. He would probally know alot more then you guys are giving him credit for. if he didnt know this stuff you would have everyone changing programs on the controller, and I dont think that would last very long.

jm2c

[Jack Neelands™]

Do-albe?

Its being done ...check out Okuma's Gosiger website

I was there 3 weeks ago in Michigan and got blown away with what they are pulling off...

Check out Feta and Mitubishi cutters in the chrome coated carbide tools that are coming out in their cataloges....

There is a report I did up in here for what they are using and speeds and feeds....minimum speeds were 15000 rpm

tis called Seriously Hard Milling

 

[ 11-22-2006, 02:36 PM: Message edited by: Jack Neelands - Rho-Can Machine. ]

[Storkman]

Ahhh he's FOS.

 

JM2C.

[gcode]

quote:

---

The GUY has never run a machine

---

best programmer I ever knew did't know feed hold

from cycle start... never spent a day on the floor

He had a PHD in physics but fell in love with Catia and got into the CAM side of things. He works all over the world as a Catia contractor

[justind]

lol thats sounds kinda like what im dealing with here - we have FIRED!!! 11 contract guys in the last yr and one engineering manager. Good help is realyl hard to find these days. I have yet to ever see a programmer worth a sh$$ with no machine experience. WE have given up and are now giving machinst from the floor a shot in programming. Cant be no worse then the contract people.

[Müřlıń®]

quote:

---

Now, how often do you see 70 rc steel anyway

---

Use it everyday.....it is called a mill xxxx file....

 

You can take the wrist pin out of a piston and I think it is almost that hard too...

[Hardmill]

quote:

---

Ahhh he's FOS.

 

JM2C.

---

Yup, 2 cents about sums it up LOL

 

 

PEACE

[Mcam Nut]

quote:

---

Cant be no worse then the contract people.

---

Are you aware there is alot of contract programmers in this forum?

[TR Mfg.]

I've done some resinking of forging dies, 65-68Rc or so. I could get clouse to those numbers using CBN and ceramic tooling. Doable, yes. Common in every shop, probably not.

[Storkman]

quote:

---

Yup, 2 cents about sums it up LOL

---

And to think ur only half that good Cheech.

[Hardmill]

quote:

---

And to think ur only half that good Cheech.

---

Thats better than no-cents

BTW wheres Mayday ??

 

 

PEACE

[Müřlıń®]

quote:

---

I've done some resinking of forging dies, 65-68Rc or so

---

Must have been some extremely shallow imp, low detail, press forging dies...

 

I been sinking dies for almost 30 years and the hardest thing I have cut is the stelite on the trimmers....I think that must be 60ish

 

 

Most dies would bust into a million pieces from die flex...

 

The difference between 62 to 70 RC is like crossing the Atlantic...

 

It can be done but the only thing I can think of is why?

 

The head pressure would turn a million dollar machine into putty in less than 6 months...

 

I have seen guys wear out a brand new Hydrotel in less than a year, slabing with a 2" future mill using TNMA 438's by not keeping the inserts changed....and those machines are massive...chips stringing off glowing red....

 

70 RC @ .05 would still have alot of head pressure on that shallow of a cut with a half inch ball...

 

The spindle wouldn't last long...

 

BTW Micrograin carbide is 75ish RC....probably standard carbide is around 70 RC.....

 

[ 11-23-2006, 07:37 AM: Message edited by: Murlin ]

[Jeff Kemper]

Ask him the manufacturer of the 1/2" he's using and to see their recommended F&S's

[Jeff Kemper]

Jack

 

Google doesn't find "Feta" carbide tools.

Lotsa cheese. Spell check?