[Kingjamez]

I just got in a couple VERY nice endmills from Maritool. They are 3 flute 45 degree helix roughing endmills. I put this 3/8" endmill in my X3 and did a 0.125" depth slot going 12IPM at 2000RPM. It seemed to work very well with no vibration, just a nice clean slot. When I removed the endmill I saw that the edge of one of the flutes was chipped. Bummer, this endmill only had about 1 minute of cutting time.

That was my first cut. I swapped out the endmill with the 2nd one I ordered of the same type and went on to do an hour of cutting with zero issues and that endmill cut through the aluminum like butter.... VERY nice.


My question is, did I get a bad endmill? Can this one still be salvaged, it's a ~$30.00 tool, and I'd like to get more than 1 minute of life out of it.

-Jim

[holbieone]

looks like it chipped because you were re-cutting chips

you need to get the chips out

as long as the tool keeps cutting use it , you may have to adjust your feed rate but it should work

[mwood3]

lol, thats nothing...I will post a pic of one of my 3/8" 4 flute errr now 3 flute endmills that i still use.

[photomankc]

Yeah it's a rougher. I'd not sweat it too much. I have a 3/8" that's all chipped up, not sure how I did that exactly. Anyway, it cuts alright but leaves a terrible surface behind on the horizontal plane. I just don't use it to surface anything but it will still pocket and side mill just fine.

[christinandavid]

Grind/file a small rad/chamfer on the corners. Sometimes the corrugated ripper form is weak on the corner in one or two positions.

I tend to do this on jobs where I KNOW that the cutter will chip on the corner, and have also got cutters cutting lovely again (yes, even on the bottom) with a bit of a refurb. Surprisingly, even on a chip halfway up the flute of a carbide endmill, the finish on the job can be dramatically improved if you diamond-file that particular flute down a bit. Its a shame to waste the other two/three perfect flutes.

DP

[roninB4]

I would agree with the above posts, it can still be used. I've also had corrugated cutters chip at the end like that but continue to use them. I would also agree that re-cutting chips is one of the bigger factors for reducing tool life, get the chips out of the cut. Most of the cutters I have will be divided into groups of NEW, ALMOST NEW, DON'T REMEMBER WHEN IT WAS NEW. These are also divided into SIDE CUTS GOOD, FACE CUTS GOOD. You can use a damaged cutter if you plan your cut to take advantage of what remains of good cutter geometry. You needn't throw it away just because it's not pristine, just plan how you're going to use it. A rough cut operation that's just stock removal doesn't require a good finish, save the good cutters for finish operations. Most HSS end mills that get dull on the sides still have a reasonably sharp face that I'll use for hole location in a plunge operation, as prep for a reamer (for eg.) or c'bore type of cut. I almost never throw away a dull end mill, be it HSS or carbide as it can either be touched up or become a special one-off cutter. If you have a T/C or surface grinder with a spin head there's no limit to what you can create with a ruined end mill. I've ground a V on the end for punch holding, lapped for pin gauges, and made sacrificial cutters from them. They may be dull but they're still good for something one day. JMO.

[Johann ohnesorg]

Well,
at 30$ a piece I would keep the old one and use it until t is really dull and then have it reground. This may be stupid for a single cutter but as soon as you have 3, 5 or 10 of the same type, regrinding time gets big against setup time of the grinder, therefore it gets cheaper.

Cheers,
Johann

[neilw20]

Where the cutter has a chipped leading edge on the long flats, a quick gash with a diamond file works wonders.
Might look a bit daggy but they work.
The pointy bits on roughing cutters can be quite weak, so carefully controlled feed rate approaching a cut will make them last longer.
On a machine that is not too stiff this is more important.
Re cutting chips is not good. Well flushed or plenty of air is the trick there.
[nomedia="http://www.youtube.com/watch?v=lzCeAsDMCR8"]YouTube - SNC00374.mp4[/nomedia]

[Kingjamez]

Thanks for the tips guys! I'll touch it up with a diamond file and give it another try.

-Jim