Endmill Wear Pattern Characteristics

[stang5197]

Does anyone have a link that shows pictures of various endmill (not inserts) wear characteristics? A while back I had seen something that showed pictures of endmills with various defects and recommended solutions to the problem. Anyone know where I can find something like that?

304 is causing some wear on the bottom of the endmill that I am not sure what the solution is.

[DareBee]

Here is one using words.
http://www.speedsandfeeds.com/PDF%20...cationtips.pdf

[big_mak]

stang, is it chipping, or wearing??

What endmills are you using, and speeds and feeds coolant????

[stang5197]

The endmill is a 1/2" 4 flute Niagara TIALN S545 series endmill.

Niagara recomends a 345 SFPM (Moderate Level) with a 0.005 doc cut.

I am running it at 2600RPM with a Feed of 14.1 with Lots of coolant

The picture of the endmill cut two parts and is chipping.

The milling operation is a profiling the outside of the part, so the endmill is cutting similar to a sloting operation with a doc of cut at 0.004" (EDIT 0.040")per pass

The program is written to lead out of the part before lowering in Z so the endmill is not plunging into the part.

Any help on this one who be greatly appreciated.

[big_mak]

5 thou doc is waaayyy to small. How thick is your part? If you are profiling, and the cutter is never fully engaged you should be able to go 1/2" Deep.

Try 1600RPM and @ 25.6"/min. Your feed numbers were a bit on the small side, I think you didn't multiply your feed, by the number of flutes!!!!!! Program the feed for this, then run the first cut at 60% feed overide, and if its good bring it up slowly.

Remember to use lots and loots of coolant, and keep the chips out of the cutting zone!!!!!!!!!

Lemme know how it goes.

[stang5197]

The cutter is fully engage 80% of the cut, the DOC is actually 0.040" not 0.004". The total thickness of the part is 0.250"

Another thought is could the chipping be caused by the entry of the endmill?

I am also thinking of ramping into the part, to help reduce the "impact" of the cutting edge at the beginning of the cut.

The thing is the surface finish looks great, and it sounds like good when cutting, but obviously something isn't right.

I will give it a try tomorrow and let you know how it works out.

[Geof]

This might sound like odd advice; don't worry keep cutting if it sounds okay and the part comes out with a nice finish. I have used HSS tools that seemed to chip on one or two teeth but then ran for a long time working well.

[stang5197]

Geof, thanks for the suggestion, but this is the 2nd endmill (identical endmill and same program). First destroyed the bottom of the flutes after 4 parts, I didn't really keep a close eye on the endmill (cutting 4 per fixture) until the over load alarm.

I am just concerned this tool is heading in the same direction. I am probably going to tweak the program as suggested and see what happens.

304 Stainless is a real pain to machine, this is the first and hopefully the last time that I am going to deal with it.

[dertsap]

try to stone a slight radius on the corners of the tool before running it

[DareBee]

Well.

You don't really want to stone a coated endmill (or you might as well not have it coated) sorry Derstap.
On this same line of thinking I really like using corner rad cutters. That same .5 cutter with an .020 rad on each tip will way outlast a square.
Niagara's are great but I find Ultratool to be much better value.

Chipping is caused by overfeeding. The numbers above are usable. I suspect that your feedramp is not appropriate.
If you are just plunging this endmill into the material at full speed that is likely the problem.

[RICHARD ZASTROW]

Is it possible that your having a workhardening problem?

[bob35]

Could be thermal issue did they recommend dry machining?