[s2jesse]

So Im trying to slot 1/32". Im using various carbide stub endmills from lakeshore carbide.

I keep breaking them.. ive tried both flat and ball endmills.

I just broke my last one. I've tried some various feeds and speeds.


Current was 5100rpm x 2.9ipm with .0156 doc full slot.

My run out on the holder is less than .0005

Im using a trico aimed directly at both sides of the slot.






Any Tips? I don't want to order a slitting saw just for this. I have to do about 10 of these little pallets.

Thanks Jesse

[zero_divide]

Whats the material?

That's like the most important piece if info!

[G59]

https://www.youtube.com/watch?v=F7bB0QCAmk8

This guy is milling 6160 at 6000rpm 0.0625 DOC and look how slow he is going. Are you anywhere near that?

[G59]

https://www.youtube.com/watch?v=F7bB0QCAmk8

This guy is milling 6160 at 4250rpm, Feedrate is at 3.74 ipm. with 0.03125DOC. and look how slow he is going. Are you anywhere near that?

[keen]

A quick read , but I don't see length of cutter mentioned. A big factor - you need as short as possible. Keen

[s2jesse]

https://www.youtube.com/watch?v=F7bB0QCAmk8

This guy is milling 6160 at 4250rpm, Feedrate is at 3.74 ipm. with 0.03125DOC. and look how slow he is going. Are you anywhere near that?

oops yes sorry... The material is 6061.. at least it should be its straight from the waterjet. I asked for it to be 6061.
Does it look like the speed in that vid? Yes looks very similar speed. I'm right around 3ipm and going half that deep. .0156 ..

Jesse

[WOTDesigns]

I would suspect vibration might be killing you. It looks to me like a thin piece of aluminum only held around the edges which will definitely vibrate at as the cutter nears the middle. I just surfaced a 1 foot square 3/4" thick part and had to adjust out the vibrations from poor holding. Your plate ratio is several times thinner/worse for vibration. Smack some double sided tape under it and I'll bet you'll be good to go. Make sure your tool is 2 flute not three if you don't have coolant. You need room for the chips to get out since you are slotting.

Flood coolant would be a LOT better too.

[zero_divide]

With coolant you would be able to make the cut- no problem.
Also it helps to have a short stickout,

In your case, i believe small flutes are getting clogged up with aluminum.

Decrease the depth of cut by half and it will stop breaking.

[s2jesse]

With coolant you would be able to make the cut- no problem.
Also it helps to have a short stickout,

In your case, i believe small flutes are getting clogged up with aluminum.

Decrease the depth of cut by half and it will stop breaking.

Thats pretty close to the settings I ran. I used both hsmadvisor and gwizard with the breakage. I ended up finishing the parts with a mill drill / chamfer mill. Not exactly what i need but still gives the overall appearence i was going for. I also suspect that the material is a little substandard. I had it mill a little in my fixture first and the cut was much cleaner looking there vs the actual part.

[SCzEngrgGroup]

You say you're using a "Trico". WHICH Trico? Is it a micro-droplet, or some kind of mist system? With those tiny tools, you MUST keep the chips away from the cutting edges, and the best way to do that is with high-pressure air. A Fog Buster works well. You also don't indicate how deep you're going. I understand your depth of cut is 0.015", but how many passes are you taking to final depth?

Regards,
Ray L.

[Steve Seebold]

With coolant you would be able to make the cut- no problem.
Also it helps to have a short stickout,

In your case, i believe small flutes are getting clogged up with aluminum.

Decrease the depth of cut by half and it will stop breaking.

I would pay attention to what this guy says. I would have suggested a depth of cut equal to half the diameter of the end mill and 4 IPM.

[pickled]

I slot with little critters like this often-ball nose works quite well. The DOC I use is usually half of what you have attempted in 6061 though I move along at about 7 IPM. I am assuming that your cutter has a 1/8" shank and you have the air pressure turned up on the coolant system to help get the chips out.

[WOTDesigns]

He is already doing almost exactly what zero posted:
Current was 5100rpm x 2.9ipm with .0156 doc full slot

Try the same cut in a block of AL and I bet it will cut all day long. Slotting that many slots in that thin of a piece is decreasing what little bit of strength it had. There is no way that cut wouldn't start to resonate after a few of those slots are put in. A couple drops of super glue or tape and it will be fine.

[s2jesse]

He is already doing almost exactly what zero posted:
Current was 5100rpm x 2.9ipm with .0156 doc full slot

Try the same cut in a block of AL and I bet it will cut all day long. Slotting that many slots in that thin of a piece is decreasing what little bit of strength it had. There is no way that cut wouldn't start to resonate after a few of those slots are put in. A couple drops of super glue or tape and it will be fine.

Thanks. and again i think your right cause the cut looked nicer when it was cutting a bit into the fixture.

[WOTDesigns]

That made me chuckle thinking about milling a vise jaw and rather than getting upset at ruining the vise jaw I got mad that the cut was so clean even though it was stuggling with aluminum a second before. :/