Depth Cut Verses Feed Rate? 6 hr operation..

[Rich05]

Good call. I checked it is / was TICN

Here is the order from McMaster:

HSS THREE-FLUTE END MILL FOR ALUMINUM, TICN COATED, 1/2" MILL DIA, 1-1/4" LENGTH OF CUT $20.09

Now for the bad news. I have ruined two of these. But besides that have been getting lots of Chip loading.

After about 15 hours have had about 3-4 times it loaded up doing 3200 rpm, .15" depth cut, 24 ipm feed rate. Here is a video of it really loading up badley at 40ipm feed rate.. What a mess.

http://www.terrablades.com/MVI_1149.AVI

[chad123]

Eeeks! You are correct, what a mess.

Ok first full disclosure. I do not pretend to be a professional machinist so take what I say with a grain of salt. There are FAR more qualified people here but I have been down this path and I have gotten things working pretty well here. I started with a Mach controlled HF mill, now we have a nice mach controlled BP clone and are getting ready to get a Haas VF-3...

First, tooling. Throw those enco Ti coated end mills in the trash. I thought the same thing at first too, Hey I can get like 14 different end mills in a box for like $50, woo hoo. Yea, not so much. Learned real fast you get what you pay for when it comes to tooling.

I now use only solid carbide uncoated two flute high helix. It might be over kill but my bits last forever, I never break edges (unless I drop the dang thing, then it is off to the regrinder) and things don't load ever. I only have a mist system and I mix it pretty rich.
The BP only has 5600 max rpm and I have found that I just don't have the cooling or spindle speed to make three flutes work effectively. It seems that the two flute are better at getting the chips out of the helix and reduces the chance of loading especially at our rpms.

If you have a chipped edge than that bit is shot and needs to be reground. Chipped edge doesn't shear metal, it just pushes. I have found this is a sure fire way to start a bit down the loading path. On the FIRST sign of loading STOP. IF you get a little load you can stop and use a scribe or something to pop out the loaded stuff and continue, I like to give it a shot of WD-40. I am sure that this doesn't do anything for more that a sec or two and is probably just a good luck charm.
The video that you posted, wow never loaded one like that. That bit is probably history. You were not cutting anything just smearing around metal.
It looks like you have a flood rigged up. Never cut without it. And I would also mix the cutting fluid richer, can't hurt.

Speed: As fast as your spindle can go. When milling alum my mill has one speed, as fast as it can go.

Feed: I have found that the recommended chip loads and feeds and speeds don't usually work very well for those of us without a mega dollar vmc. I usually start out with something conservative and in the ball park then start upping the speed until things start getting funky, bad finish, loading, machine groaning...

You have a small machine, I have a bigger, small, machine. A big real cnc is a totally different animal. I realize that you want to get stuff made as fast as possible, however loaded bits and ruined work takes a lot more time than slower and cutting correctly.

Anyway just some suggestions. Good luck.

Chad

[cnckid]

That is some excellent advice from Chad. When it comes to tooling, never buy the el-cheapo crap. I wasn't able to see your video for some reason, so what is the grade of aluminum you are cutting? If it is something like 3003 series, that is really gummy, and the WD-40 trick is the best for that. I use 3 flute endmills from these guys (http://www.lakeshorecarbide.com/). I cut aluminum on a daily basis, running a .750 diamteter cutter at 8150 rpm, 150 ipm, .300 depth of cut, 85% stepover. I have found the ZrN (ZIRCONIUM NITRIDE ) works best and tool life is exceptional. Check their website, they have speed and feed charts and cutters with other coatings for steel, stainless, etc. and their prices are better than anyone else I have found.