Mitsubishi facemill cloudy finish in 6061.

[empower]

hoping to get some help/input. i have a 3" shoulder/facemill from mitsu, using their LC15TF diamond coating, .031" corner rad.

spinning at 24k rpm (recommended by mitsu rep, have tried lower with same results) in HSK63 holder. taking .5mm material for finish pass. have tried feed rates from 100-700ipm.
feel wise the surface is impeccable, just visually looks cloudy. for how fucking expensive these inserts are (~$40/insert) i'd really like to get the best finish possible out of them.
has anyone tried these with good results?

 

[boosted]

Looks dry to me. Like it's dragging a chip. Through spindle coolant?

We use that same insert with good results, but at a much lower SFM (2in facemill @ 16k). Finish pass at 100IPM.

 

[empower]

Looks dry to me. Like it's dragging a chip. Through spindle coolant?

We use that same insert with good results, but at a much lower SFM (2in facemill @ 16k).

yup, TSC and flood. the way it creates mist in the machine - i find it very difficult to believe its recutting chips.

 

[boosted]

If we turn coolant off we get a cloudy finish like that. Even with air blast on.

I'm theorizing that with how fast it's whipping around, it might be dry(ish) on the cutting edge. Perhaps that's a stretch though. Would be pretty easy to slow it way down and take a peek. Oh nevermind, I see you tried that.

 

[crossthread82]

I run my 2" at 12500rpm and 100ipm taking a 0.005"-0.010" finish cut 85% woc (Using flood coolant, no tsc) using the exact same insert. Can see myself in it. My guess is you're spinning it too fast and glazing the material because its vaporizing the coolant.

 

[boosted]

It's not thunderbar or some other crappy material is it? I used to think that wasn't a thing, until we got a huge batch of service center 6061 bar in here that looked and cut like crap no matter what.

 

[empower]

It's not thunderbar or some other crappy material is it? I used to think that wasn't a thing, until we got a huge batch of service center 6061 bar in here that looked and cut like crap no matter what.

6061 bar stock. finish looks great with my fraisa endmills so i doubt its that.

 

[empower]

I run my 2" at 12500rpm and 100ipm taking a 0.005"-0.010" finish cut 85% woc (Using flood coolant, no tsc) using the exact same insert. Can see myself in it. My guess is you're spinning it too fast and glazing the material because its vaporizing the coolant.

hmm, let me try to bring it down to that and see what it does

 

[Mtndew]

Have you tried a lighter depth for finish pass? Like somewhere around .005"/.01"?

Or maybe go to the other extreme and go heavier.

 

[empower]

Have you tried a lighter depth for finish pass? Like somewhere around .005"/.01"?

Or maybe go to the other extreme and go heavier.

have tried .01 and .02" currently running at 8500 rpm and 100ipm at .01", will post pic in a few

 

[empower]

24k rpm 100ipm on the left. 8500 rpm 100ipm on the right. think i'm gonna try 10k rpm 100ipm next with like .005" material

 

[crossthread82]

Is this the first time using the LC15TF inserts? It's hard to tell from the picture but is the one on the right more shiny just has more noticeable feed lines?

For me every once in a while when I put new inserts in it won't leave a good finish until I run them in for a bit. I've also taken the inserts out and then reinstalled them and the finish improved. Mitsubishi doesn't claim this tool to be a finisher so they'd probably say your original finish is more than acceptable.

Best finish I've ever gotten with mine was taking 0.002" finish cut 6500rpm ~40ipm dry , but I opened the door and squirted alcohol onto the top of the part before the cut. Came out like a mirror, damn near the same as my pcd facemill.

 

[empower]

Is this the first time using the LC15TF inserts? It's hard to tell from the picture but is the one on the right more shiny just has more noticeable feed lines?

For me every once in a while when I put new inserts in it won't leave a good finish until I run them in for a bit. I've also taken the inserts out and then reinstalled them and the finish improved. Mitsubishi doesn't claim this tool to be a finisher so they'd probably say your original finish is more than acceptable.

Best finish I've ever gotten with mine was taking 0.002" finish cut 6500rpm ~40ipm dry , but I opened the door and squirted alcohol onto the top of the part before the cut. Came out like a mirror, damn near the same as my pcd facemill.

i've been using them for a few months now, but the finish has always been like this.
the one on the right definitely looks to be a bit brighter so i'm doing a few more tests at lower rpm and feed rates.
the rep actually said he was really surprised it looks this bad, says it should look way brighter.

 

[chad883]

What is your coolant concentration? I run mine very high for a better finish. I put cutting oil in all the lathes at work and it is a huge improvement on finish. I don't actually check the concentration in the mill, but higher is better.

 

[empower]

What is your coolant concentration? I run mine very high for a better finish. I put cutting oil in all the lathes at work and it is a huge improvement on finish. I don't actually check the concentration in the mill, but higher is better.

just under 10% using qualichem 251c.


the right is 10k rpm, 60 ipm and taking off .005"
definitely shinier, but the cut marks are way more evident now

 

[boosted]

Always on the same machine? I had a pretty good machinist spend a whole shift chasing something like this with a different insert on some cast material. He ran an indicator on the ends of the inserts to check individual height, and then threw a testbar in the spindle looking for squareness issues... My assumption is always that it would look better if one of the inserts was dragging or the head was out of tram though...

IIRC he wound up turning the facemill into a fly cutter and slowing it way, way down. Total overkill but it worked.

 

[empower]

Always on the same machine? I had a pretty good machinist spend a whole shift chasing something like this with a different insert on some cast material. He ran an indicator on the ends of the inserts to check individual height, and then threw a testbar in the spindle looking for squareness issues... My assumption is always that it would look better if one of the inserts was dragging or the head was out of tram though...

IIRC he wound up turning the facemill into a fly cutter and slowing it way, way down. Total overkill but it worked.

i have this exact tool/inserts on 3 mills. Zimmerman 200k lb gantry, ibarmia 45k lb traveling column and haas vf4. they all produce roughly same cloudy finishes.

 

[Houdini]

I would say either too many RiPumS(heat/tearing)
And I agree, your machine is never perfectly tram.
When I used to run Mit shells, we had to make sure there was a trailing insert low.
If it was perfectly tram or a leading insert low it looked like this.
It was when the trailing insert was high it leaves a ghost cut/rub.

Try running it backwards direction.

edit: ahh different macheens!

 

[crossthread82]

Is it the 3 or 5 insert version? Usually a 0.005" pass at 0.0015-0.002ipt leaves a pretty acceptable finish. Is the coolant old? I'd run three identical passes one with coolant, one dry, and one dry with alcohol and see if it improves.

Edit: Personally if I'm going for pristine finishes I just pull out the pcd, it works every time. I have a 3" Sumitomo HF 9 insert all of them height adjustable one pocket has a wiper and it leaves mirrors in 6061 and 7075.

 

[empower]

Is it the 3 or 5 insert version? Usually a 0.005" pass at 0.0015-0.002ipt leaves a pretty acceptable finish. Is the coolant old? I'd run three identical passes one with coolant, one dry, and one dry with alcohol and see if it improves.

Edit: Personally if I'm going for pristine finishes I just pull out the pcd, it works every time. I have a 3" Sumitomo HF 9 insert all of them height adjustable one pocket has a wiper and it leaves mirrors in 6061 and 7075.

5 flute. coolant is 2 months old. rep is sending me some different inserts on monday to try out, we'll see if they make any difference.