[dwomble]

Hello everyone,

I'm pretty new to milling and having some trouble milling brass sheets. I am milling 0.01" thick brass in 2 passes at about 0.005" and running the mill at 4-5 ipm and 4500 RPM with a 4 flute 1/8" carbide center cutting square endmill.

I tried running the mill closer to what some of the calculators said the mill should be at but I found that this gave decent results.

Any suggestions for the speeds and federate for milling 0.01" brass with a 1/8" endmill??? I'm sure that what I am doing is incorrect...

The problem is that occasionally, the cutting edge on the head of the endmill forms a cap of brass over it. This was not really a problem before but now we are milling assemblies and after the first part is made the end mill develops this cap over the head and can no longer penetrate the brass.

I am not sure if it is a problem with my speeds and feeds, anatomy of the endmill, or lack of lubrication.

Also, my machine can not exceed 6500 RPM.

Thanks!

[LeeWay]

Are you ramping in and out? If not, then try it. It may help shear that off.

[dwomble]

No, I wasn't. I was plunging into the material. Thanks, I didn't think of that. Any other suggestions for the speed and federate? I have a feeling that I am using a speed and feed way off what they should be.

[LeeWay]

I would say that you can go as fast as the mill will spin. You should be able to increase the feedrate as well, but that really depends on your work holding and the size of the sheet and part. Brass cuts nicely. It is probably the easiest metal to machine other than maybe zinc.

[dwomble]

So far I tried ramping in and out of the part and that seems to have worked for knocking off that cap that developed on the head of the end mill. Now, I guess I need to play with my feed rate a bit to find out what works best... Thanks for your help!

[m4bushy]

A 3 flute endmill would be better. Ramping in at 20-30 ipm at 3500-4500 rpms