What am I doing wrong? Feed, RPM, tool length...

[MikePP]

Hello friends.
So. There is a bounce in the chamfer area. On the plane, no problem. Aluminium alloy. Cutter, three flutes, 8 mm (1/3 inch) diameter, 60 mm (2.36 in) long. 7000 rpm, feed 500 mm/min (20 ipm). Cutting depth - 0.2 mm. This is the final pass. Yes, the cutter moves away by 0.025 mm, but this is not a problem.
It's hard to photograph, but I tried.
What recommendations can you give? Is it possible to perform such an operation in one pass? Is it possible to perform such an operation?

Thank you.

 

[Mr.Chipeater]

you've got a 3 flute cutter sticking out 7.5xD. In our experience, such a flimsy tool can't be reliably run over ~2000rpm without chattering.

 

[SteveEx30]

Use a bigger cutter. What is the machine?

 

[Ox]

Or rough the corners out...


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Think Snow Eh!
Ox

 

[MikePP]

Thanks friends.
Mazak v-414.
I don't have a thicker cutter with this length yet. The same material thickness in the corners is 0.2 mm.
There was no 0,2mm allowance along the Z axis after roughing. Can the stability be affected by the contact of the part with the butt end of the cutter?
Tomorrow I will be able to experiment with lower rpm and feed.

 

[Mtndew]

Assuming you are holding the end mill in a GOOD collet, hydraulic holder or shrink fit holder, I would slow the rpm's way down if you must take a full length cut with the 8mm end mill and adjust the feed accordingly for finishing passes. If you're trying to do this in all 1 cut you're just going to have issues.
But definitely get a larger end mill, like a 20mm (3/4") diameter for that length of engagement.
OR
Or you can go with a necked end mill and take depth cuts.

What machine are you doing this on?

 

[Ox]

Thanks friends.
Mazak v-414.
I don't have a thicker cutter with this length yet. The same material thickness in the corners is 0.2 mm.
There was no 0,2mm allowance along the Z axis after roughing. Can the stability be affected by the contact of the part with the butt end of the cutter?
Tomorrow I will be able to experiment with lower rpm and feed.

Does this machine not accept G code?

I doo VERY little in the world of canned cycles, and I have never ran a Yamazki before, but even if the cycle doesn't allow you to rough and finish, I am sure that you can call the same canned cycle 2wice, with different parameters each time to emulate a rought/finish cycle.


--------------

Think Snow Eh!
Ox

 

[SteveEx30]

Thanks friends.
Mazak v-414.
I don't have a thicker cutter with this length yet. The same material thickness in the corners is 0.2 mm.
There was no 0,2mm allowance along the Z axis after roughing. Can the stability be affected by the contact of the part with the butt end of the cutter?
Tomorrow I will be able to experiment with lower rpm and feed.

Definitely get some bigger cutters...

And to answer your question, to do this In 1 pass.. prob not. This a high volume part? You need to do this 1 pass??

 

[MikePP]

Unfortunately, I did not have any opportunity to repeat the experiment. However, the advice to use low RPM for a long tool is more than correct. Thanks a lot. I received confirmation in another work. After lowering the speed, the squealing disappeared and the surface cleanliness improved at certain points. Also a long tool. Later I will show the results with an octahedral prism.

The prism has two inches vertically. Processing area. There were two passes, but defects occurred only on the first. The second pass did not remove the material.