Machining Videos

[teemee]

6-side machining:

http://www.youtube.com/watch?v=hjBYZn5y2-I

The "smallest" Mill from Zimmermann:

http://www.youtube.com/watch?v=nNP0NnVzqno

[Adambomb]

Here's another one for "machining freaks"...some end mill on end mill action, and some end mile on file action.

http://www.youtube.com/watch?v=fD2Mo-UrUU0

[Mikey Antonakakis]

:O

I just found this thread, and I'm speechless. I don't think we're even in the ballpark of what our machines can do...

I think our CNC mills are 15hp. What kind of speeds feeds and depths would you guys run on them?

[kapps]

It comes down to lots of research and practice. I became a bit obsessed with machining a couple years ago. Look for forums... practicalmachinist.com is one that I'm on.

We only have a 5hp, 40 taper machine with 3k rpm spindle. I have roughed aluminum at up to 40 ipm, .300 depth and 50-60% stepover with a 3/4" 2 flute. I've been playing around with higher doc with less stepover to take advantage of some chip thinning action to allow more feed with our limited spindle speed. 15hp is a good amount of power. You should be able to throw around some 1" and up endmills pretty good. Remember, feeds and speeds don't change with spindle power. You just can't take as deep a cut with a low-power or less-rigid machine. Do some googling, can find good approximations for SFM (changes with stock material) and chipload (depends on end mill material and diameter). From there, you should be able to calculate feeds and speeds.

[Jersey Tom]

A little unpleasant chatter in one of those Cubic machining videos. Cutting brass?? C'mon, amateur hour... also looks like they mislabeled some aluminum as steel.

http://www.youtube.com/watch?v=kmReHL3n0FM

Ceramic cutters are fun.

[Mikey Antonakakis]

Awesome, thanks.

Yeah I'm taking a computer aided manufacturing class and we've been going over cutting theory but I haven't really had a chance to try putting any of that into practice. I also might be completely wrong about the machines being 15hp... but still, I can't wait to start applying some theory here, I am completely blown away by those videos.

[Jersey Tom]

15hp is enough to push a lot of metal.

More often than not, workpiece, machine, and tool rigidity are the limiting factors. When you get into really aggressive MRR's, chatter breaks tools very quickly. Good reason to design your billet parts so they can be clamped very rigidly and milled with big tools. It can for example reduce the cycle time on a billet upright from ONE WEEK to ONE HOUR. That's no joke.

Go carbide all the way if you have 7500+ rpm on your spindle. If you can't get the SFM up past 500 or so, might as well use tool steel.

with a 0.500", 3FL flat carbide EM in aluminum.. 6000RPM / 70IPM would be an easy starting point (say full 0.500 radial, 0.150 axial DOC as a starting point). 8000RPM / 100IPM isn't unreasonable.

In steel I've become a big fan of TiCN coated 6FL tools lately. Think we were taking 3000RPM / 45IPM, full width 0.200 axial DOC cuts in 1018.. on a 23 year old machine. Fun fun. Indexable tooling rocks as well. Absolutely amazing the feeds and speeds you can run with good Kennametal tooling.

But like I said.. rigid work- and tool-holding comes first. From there you can go bananas.

Edit - Also... forget setscrew toolholders. That shit is whack. Shrink fit toolholding is probably overkill at the university shop level.. but collet chucks at a minimum. Most of our shops had at least a few ER16 and ER32 holders around.

[AxelRipper]

http://www.gaskrank.tv/tv/moto...aishin-cro-10963.htm


essentially cnc pron

[kapps]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jersey Tom:
Also... forget setscrew toolholders. That shit is whack. Shrink fit toolholding is probably overkill at the university shop level.. but collet chucks at a minimum. Most of our shops had at least a few ER16 and ER32 holders around. </div></BLOCKQUOTE>

I disagree. I've seen endmills get pulled out of collet chucks when doing heavy roughing. Not the case with tool holders. Also, collet chucks are $150 a piece plus the collets (we have 3/8-1" in 1/64's plus a couple smaller sizes). Tool holders are $50-60 a piece. More than likely, you have a few endmills that will perform 90% of your operations. Get a tool holder or two in each of these sizes and maybe one collet chuck for odd-sizes or finish machining.

Shrink-fit tooling is nice but WAY OVERKILL for what we're doing. I've heard it also creates an almost too-rigid connection so harmonics of the cut can cause problems.

As for tooling, 2-3 flute for aluminum. Solid carbide will last forever as long as you don't run it into the vice or something. Just remember, carbide is harder but is more brittle than HSS; it likes less chipload than HSS but it also likes heat. This means you can pump the speed way up. The 5-6 flute TiCN coated solid carbide are money in pretty much any steel you can throw at it (including hardened gears...).