Breakng End Mills

[leoE4H8W]

I keep breaking end mills, can someone help?

[seth.madore]

The file you shared does not have any setups or toolpaths applied, so it's near impossible to coach you on better practices.

I know what that feature is, so I'm struggling to understand what would cause tool breakage. 7075 aluminum, while tougher than 6061, is still pretty darn easy to machine. Where are your endmills breaking?

[leoE4H8W]

It won't let me load the f3z.

[seth.madore]

You can right click on the file in the data panel and select "Share Link" (make sure it's able to be downloaded). Note; this won't work if you're on a Personal License.

[seth.madore]

What happens when you do try to attach the .f3z file?

[leoE4H8W]

Here's the link https://a360.co/3Lw7J6k

[seth.madore]

As you're on a Personal License, the file isn't able to be downloaded from that link.

Please expand on what issues you're running into when trying to share the .f3z file

[leoE4H8W]

This is the message I get.

Correct the highlighted errors and try again.

The attachment's help.f3z content type (application/fusion) does not match its file extension and has been removed.

[seth.madore]

Put it in a .zip file and share that instead

[leoE4H8W]

Try this. 

[seth.madore]

Well, you're running at a lower RPM than I would recommend. When I've done these on my Mori, I tend to run at 800 SFM. If you're limited to the RPM of 5,000 (which puts you at 400 SFM), I'd reduce your feedrate to 30IPM.

For the trigger slot, I'd suggest switching to a .250 endmill

For the overall pocket, I favor a Helical #81504, which is a .375 endmill, stub flute, reduced shank. Sweet tool that I push to 8200 rpm and 95 ipm (which you won't be able to hit with your Tormach!!!)

Where exactly is the tool breaking for you, that answer still is open...

[leoE4H8W]

It breaks at the shaft, like the feed rate is to fast. I slowed it down to 50%, but it still broke.

[seth.madore]

I'm sorry; where in the part is it breaking. Right off the bat, deep in the part, in a corner, etc etc.

I'm assuming that you're using flood coolant, right? If you're just using mist or going in dry, that could likely be the source of the issue.

Can you share some pictures of the broken tools and the pocket where they broke?

[leoE4H8W]

Yes, when I get to the  I send.

[leoE4H8W]

Here's the pics and yes I use flood coolant.

[seth.madore]

I would suspect, based on the pictures, that your machine is being fed to fast and your 5k RPM is not keeping up.

Max RPM, gentle feed for your machine, would be my recommendations

[leoE4H8W]

Thanks for your help. I will try your reommendations. Can I change the feed rate in Fusion?

[TimMartin.]

That toolpath should run just fine. Make sure your endmill doesn't stick out further than it has to. Make sure your part is properly secured in the Fixture/vise. Use a quality name brand endmill and your problems will disappear. Use a 2 or 3 flute, your endmill might be loading up.