Hard milling

[DG]

Just a quick question. I am to try milling hardened steel dies for the first time. S7 at Rc 58. I'm really excited about this as it potently can save me a lot of edm electrode burning time. I have read all the previous posts that I could find about it and have absorbed a lot. My question is that as I post my feeds in IPM, They don't seem fast enough. I am using a .1875 two lipped ti-acn ball end mill to rough, a .01 stepdown,a .005 stepover and 30000 rpm. Does 60 IPM sound right That's at .001 per tooth. I will finish with a .06 2 flute Ti-Acn, .0005 DOC and .0005 stepover at 40000 and IPM of 40. Does this sound about right? I will climb mill and run a light oil mist with air. Just sounds slow to me? Can anybody help a hard milling beginner? please.

[?Mark]

edit

[DG]

I don't understand?

[DG]

I hope that someone can help me out. I just don't want to kill my tools.

[Hardmill]

You want to at least dbl your chip load, You may even

increase from there.

Leave a little more on your finish cut .003 min.

 

And your SFM is way up there (almost 1500), start at

about 800sfm.

 

PEACE

[DG]

Thank you Hardmill, I have read your posts extensivly and learned a great deal . I should double the chip load on both paths? And will cleaning up .003 DOC give me a mirror finish?

[DG]

So I've got .187 at 16,000rpm and 64 IPM at .002 per tooth? So I would've burnt up then huh? Is the .0005 step over at the finish pass sound right?

[chip]

I would think it nearly impossible to DBL (Chip) me! There is only one of me. DBLing me would definitly scorch your tools. TGIF!

 

JK

[DG]

lol ! You can never have too much of a good thing!

[Hardmill]

Too light a chip load will just rub and dull your tool.

And make sure your oil in the mist is very /very /very light,

You dont even want to see it.

 

 

PEACE

[DG]

Thank you sir.

[Hardmill]

 

 

PEACE

[?Mark]

quote:

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I don't understand?

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Sorry, didn't have spare minute at the time...

 

Besides, with Hardmill you are in good hands

 

[DG]

's ok. thanks. So I be cutting some hard chips tomorrow. I'm going with .187 @ 16000 RPM .002 p/t for 64 IPM. .010 DOC, .005 stepover to Rough. Then .062 @ 40000 RPM .0005 p/t for 40 IPM .003 DOC, .0005 step . To start out. No guts, no glory!

[?Mark]

DG,

Remember: DO NOT DWELL.

If you stop a feedrate while endmill is in contact with hardened materiall it'll kill it pretty fast...

 

quote:

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No guts, no glory!

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[DG]

Where would it dwell? I will use rough pocket, helical entry, center for rough and parallel climb for finish.... Don't scare me

[Jeff the haas_guy]

I use a straight air blast when hard milling.

Coolant when drilling and tapping hard material.

[DG]

Thank you guys for helping me out. I'll give a holler back and let you know my results. Gotta run for fish& chips! And a beer or two!

[?Mark]

oh, and there will be plenty of sparks...

[Storkman]

What teh heck does Hardmill know about hard milling? My guess is nada.

[Carl Hessig]

Here is a link to RobbJack's guidelines: http://www.robbjack.com/html/tech.html

Not sure what coating your using but I would suggest TiALN or ALTIN for steel that hard. Some other good brands are OSG and Fraisa. I even tried Garr's new DieMold endmills recently with good results. To get your feeds & speeds use the tool manufacture's information to start with and go up from there. And note that all tools are not the same so try different brands.

 

Carl

[Jeff the haas_guy]

I use strickly OSG cutters, drills and taps.

4040 series is very good for side milling.

[Hardmill]

quote:

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My guess is nada.

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So now you speakin "mexican"

 

 

PEACE

[HevyMetl]

I have a couple of spreadsheets from Makino and TESCO(seco) if you would like to have them drop me an emial. Makino's asks for some specific information and then spits out the numbers for stepover, doc, and material to leave. This is all based off of hardness of material, diameter of cutter, average angle of surface....Drop me an email and I will send them to ya. You see the numbers and won't believe it until you cut it. The Makino spreadsheet works great for OSG cutters. The Tesco spreadsheet is set up for their cutters, and is a little to aggressive for OSG, but their cutters love it.

[DG]

OK I'm cutting and all looks fine ,But....My speeds got all knocked down in the post? especially in the helical entry. I know this is a Mastercam issue. My entry speeds got knocked back from 300 IPM to F.01 which doesn't even move. Is this tied into high speed maching parameters? I had to go back and open high speed parameters and bump up my min speeds, but I didn't use the high speed function. And even then all my speeds got knocked back. The tool is cutting like its in butter and I know I can crank it up. My speeds got kicked back to F30 from F73 on my radial cuts.???