Milling 6061 with X3, need help

[dneisler]

I am having some issues I think with my X3 with CNC Fusion ballscrews. Not with the CNC part, it is working great, but with cutting.

For the past week I have been trying to cut a part from some 1" thick 6061. And I messed over a 12" of material trying to cut a 2" part. I just can not profile cut to any DOC that seems resonable. The deepest profile cut I can make before the noise and viberation is ungodly is .025" / pass. Is that normal? Shoun't I be able to cut a deeper DOC. I am using a 3/8" 2 flute HSS end mill @ 2000 RPM. I have tried everything from 1 IPM to 15 IPM.

I will also note, the finish on my X axis cuts are nice, but the Y-axis finish SUCKS! Even after .02 finish cut.


Need assistance badly.

[KTP]

Is it a new endmill or a worn out used one?

Are you using any mist or coolant?

How long is the endmill? Trying to take a deep cut with a 3 inch long 3/8" diameter endmill would be bad...

[dneisler]

It is mostly dry cutting now, still working coolant setup.
DOC I have tried started at .0625 and got smaller. End mill is chinese junk, but only about 2 long. About 1.1" sticking out of spindle. It was not used very little, but I have sense threw it away and I have a new one I used. It did the .025 DOC nicely, but when it would do a full profile it was noisey and would viberate, not as bad as the old, but it was allot less DOC.

[wwendorf]

Check your gibs on your Y axis to make sure they are snug. Perhaps you are getting some wiggle on the Y axis that is causing the bad cut? That's the only thing I can think of that would give you a bad cut on 1 axis but a good cut on the other.

Wade

[dneisler]

I was thinking that too, but I was leaning toward the Z. I will check both again. This is frustrating me, I am trying to get ready to start cutting my Belt conversion parts.

[tauntdesigns]

I was using the gold Chinese endmills(EM) and they were very loud and got dull quickly and then sounded like it was beating the material off instead of cutting it.

I bought some cobalt end mills and the beating sound went away. I used them(3/8, 1/2, 3/4 EMs) dry on a lathe conversion I did and they are still sharp and cutting good. There's still some noise from the sharp cutter, but no beating sound.

I haven't pushed my X3 very hard yet so I don't know what depth of cut I can get away with. I haven't done any plunging with the new EM's yet( the Chinese ones didn't like it).

I did all my milling in pockets at .050" depth of cut and step over at 1/2 the cutter diameter and leaving .050" on the profile for a finish pass and spring pass and repeat until depth reached.

All climb cuts

[wwendorf]

Here's what I use on my Syil SX3 for DOC and speeds in 6061 aluminum.

.125" EM - .035 DOC @ 6ipm
.25" EM - .08" DOC @ 11ipm
.50" EM - .10" DOC @ 13ipm

I don't use any EM's over .5" so I can't comment on that. I also use the Tormach tool holders which are AWESOME and give a WONDERFUL finish.

Wade

[digits]

If you're sure it's properly trammed and the gibs are tight, have you checked that you're not getting aluminium welding to the cutter and dulling it instantly?

According to ME Consultant, you probably want 2,000 rpm, 9IPM with a 3/8" 2-fluter.

[wwendorf]

Oh yeah, my RPM is 3400. I forgot to add that. I also use a fogbuster coolant system (www.fogbuster.com) which makes a huge difference in the life of the tool.

Wade

[Ron111]

Wade what setup do you have for your 3450 rpm?

Thanks,

Ron

[wwendorf]

I got the new pulley's with my Syil America SX3. Works great with not much loss in speed and power. I'd love to get closer to 5000-6000 rpm, but 3400 works for now.

Wade

[digits]

Originally Posted by wwendorf I got the new pulley's with my Syil America SX3. Works great with not much loss in speed and power. I'd love to get closer to 5000-6000 rpm, but 3400 works for now. Wade

5000-6000 is a lot of fun - I've done a few test cuts with a 10mm (3/8") endmill, 1mm deep (0.04") at 1100mm/min (44IPM) (not on an X3 BTW) and it was like the preverbial hot knife through butter. Well, except that butter doesn't weld itself to the knife - I really need to get flood coolant going again!