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cutter vibration or machine fault?
I'm machining some cool 3d parts and some sections have odd cutter marks.
It's as if the ball nose end mill is cutting at slightly different depths.
You can see them but barely feel them with your fingers.
I'm guessing less than half a thou.
Interesting that their location is at the point where there is a double step.
Plain round sections are flawless.
I'm using a 1/4" 2 flute ball end mill sticking out 1.35" from the tool holder.
6000rpm (max), 0.005" cut depth, 0.005" stepover at 24ipm.
Wondering if its cutter vibration or is my Mini Mill worn out?
Timothy
Re: cutter vibration or machine fault?
Re: cutter vibration or machine fault?
I don't think a G09 will help.
I added a small 5 thou radius in all the tight corners so the cutter wouldn't have to stop and it still makes those lines.
I reduced rpm and cut the feed rate in half.
Still no difference.
Tomorrow I swap out cutters and tool holders.
Timothy
Re: cutter vibration or machine fault?
I'll have this problem at times. I believe it's a problem between climb and conventional cutting since the path is a zigzag.
I've minimized the problem by making the tool 2 flute and new. And if it's still an issue I'll make the path zig only. This adds a ton of time but when I have to, well, I have to and it works.
Re: cutter vibration or machine fault?
does your mill have the high speed machining option , those machines can be pretty jerky without it . Also have you tried g187 ?
There is a setting that adds a bit of rounding to smooth things out but it's been a while so I can't remember what setting it is
Re: cutter vibration or machine fault?
We have high speed machining. I’ve tried G187 P1 through P3 (its been a while so memory hazy). I ended up keeping it on the medium setting I think. Havent looked at it since the first experiments. I can look Monday. I was having the same problem on our new at the time VM-3 as our 5 year old VF-2ss. So I concluded it was just the nature of the beast but I sure hope there’s a better answer than mine.
Re: cutter vibration or machine fault?
No high speed machining.
A G187 seems like it's just a G09 but for the whole program.
Setting 85 is set to 0.005"
I switched out the cutter for a new super high quality one and even put it in a brand new tool holder.
Still the same.
Then I changed the tool path to a climb mill zig only.
Still there.
What's really frustrating is that on other parts of this piece the contours are absolutely perfect.
Since I bought this Mini Mill used, I'm wondering if there are some parameters that have been altered.
Is there a quick way to reset to all the default settings?
Timothy
Re: cutter vibration or machine fault?
Could you rotate your part 90 degrees, repost the program, and try cutting it again? If you have an axis issue, that might bring some things to light.
To me, 1.35" hanging out on a ¼" cutter seems like a good bit, though you've made big changes in revs and feed with no apparent change, it sounds like? ER holder?
PM
Re: cutter vibration or machine fault?
I rotated the part and ran a few different versions.
The marks moved with the part to the new location.
First ball end mill was in a side lock tool holder.
Second one is in an ER20 collet.
I'm leaning towards a CAM fault.
The G19 circular path in made up of five or six segments in the problem area.
The larger areas with no deviances from the circle are one or two circle segments and they are absolutely perfect.
Timothy
Re: cutter vibration or machine fault?
Timothy,
What are you using for CAM? If it's Fusion 360, and you don't have any secrecy-related issues... could you upload the F3D file or email it so I could take a look at it?
PM
Re: cutter vibration or machine fault?
flawed finishes aren't uncommon with haas but if rotating it produced the same results then it's going to be in the programming . a tighter tolerance in the cam software might help with blending oddball spots together better
Re: cutter vibration or machine fault?
I'm using BobCad/CAM Ver30 pro.
And this job has a disclose agreement attached to it.
Although I might be able to clip out a section...
Which format is best for you?
Timothy