Looking for a 3/16" stub corncob rougher for aluminum, anyone?

I have a production part that I need to slot .235" deep in 6061 with the least cutter force and absolute least lifting from the cutter. I think a corncob rougher is the best tool design for the job, correct me if I am wrong, but the only one I have found is Accupro from MSC. Suggestions please! This will be a long running job, like endless, so shaving a few seconds off each part is worth it.

This is a .24"ish x 1" x 6.25" bar that I am making from a 12"x12.9" plate held down with vacuum and stops/clamps on all sides catching the bottom .05" of the plate. All surfaces must be machined and cosmetically appealing. I am currently using regular length corncob mills from Maritool but when I try pushing them, more than a .0014" chipload, they snap off at the end of the flutes. I can't saw it because I have a vertical mill and will be slotting in both X and Y axis.

Would a "regular" but reverse helix endmill do you any good? If you have plenty of coolant flow it should clear the chips anyway, and the reverse helix will push the plate down and allow you to up the feed to the tool's limit.

Harvey makes "downcut" endmills for plastics, might work OK for your Al job.

Harvey Tool - Carbide Plastic Cutting End Mills - Square Downcut 2 Flute

My crap connection lead to a double-post...

David,
Try Lake Shore carbide, they have the "fireplug" series of roughers. Even though they are 4 flute, I use them in everything from 6061, to 6Al-4v.

Best of luck

Chris

Milland said:

Would a "regular" but reverse helix endmill do you any good? If you have plenty of coolant flow it should clear the chips anyway, and the reverse helix will push the plate down and allow you to up the feed to the tool's limit.

Harvey makes "downcut" endmills for plastics, might work OK for your Al job.

Harvey Tool - Carbide Plastic Cutting End Mills - Square Downcut 2 Flute

Click to expand...

I don't think a downcut mill would work, the bottom of the slot is only around .015" thick and the current tool is bulging the foil already. Speaking of Harvey I am trying one of their 3/16" 5 flute finishers on this job, interesting tool.

Fulcircleny said:

David,
Try Lake Shore carbide, they have the "fireplug" series of roughers. Even though they are 4 flute, I use them in everything from 6061, to 6Al-4v.

Best of luck

Chris

Click to expand...

Thanks, for $15 it is worth a try, the .312" LOC looks good. The Accupro mills are $49.

GARR has a rougher they go to 4.0mm diameter. Below is the link to the catalog

http://www.garrtool.com/doc/pdf/ARC.PDF

Never used them but I've used the other multitude of GARRs tools from HP endmills and drills and have never been disappointed.

Whysosharp said:

GARR has a rougher they go to 4.0mm diameter. Below is the link to the catalog

http://www.garrtool.com/doc/pdf/ARC.PDF

Never used them but I've used the other multitude of GARRs tools from HP endmills and drills and have never been disappointed.

Click to expand...

Perfect, that is just what I was hoping to find.