On Saturday 16 February 2013 12:20:30 Viesturs Lācis did opine: > Hello! > > Since I have totally zero experience with milling and what tools > should be used, I would appreciate some hints. > How good are single-flute endmills? Do they induce more vibration than > 2-flute endmills? It seems to me that single flute endmills might be > easier to resharpen. Is that really so? > I so far, have only tried to resharpen the ends only if both 2 and 4 flute mills. With moderate success as they are all carbide, and the diamond disks available for a dremel, which I turn in the mills spindle since the dremel turns them too fast, ablating the diamond due to the heat, are a bit coarse grained to sharpen carbide with. I get better results when the touch is under a thou, and the table is swept back and forth. You can see an individual grain of diamond, the tallest one on the disk, sweeping back and forth across the face of the edge. This is not only a very slow, time wasting procedure, it still leaves a far rougher edge than it had when new.
A single flute mill on my toy, creates far more vibration than its worth. and climb cutting with a single flute cannot be done in metal, the table will be pulled forward, the next time the edge comes around its too deep a cut & the mill snaps off. Good in wood though, leaving a much smoother finish that I have gone directly to wiping a few coats of Sam's Stuff on for finish. Generally, use the 2 flute, TiAN coated mills on alu or brass, and the 4 fluters, TiAN coated, on steel. If the tables are tight, climb cutting is preferred because dig cutting starts out with just edge contact & drives the mill deeper, skidding along until enough pressure is present to make it start cutting. The thickest part of the sliver cut will then be as the edge clears the material, whereas the climb cut, starts out thick, assuring that it is cutting, and gradually thins. Edges last longer when there is enough mass in the cut away chip to carry away the cutting heat. > I also would appreciate any tips for sellers in Europe with reasonable > pricing. I am currently paying from 9 to 13 dollars for carbide, TiAN coated, std length 2 and 4 fluters, both in square and ball nose styles. Your 8mm would probably scale to 12-16 dollars (equ in Euro's) I'd think. I have a plastic container the dull and broken ones get tossed in as carbide is recyclable. > As I will purchase milling motor from these guys, I am > currently looking at 8 mm endmill here: > http://www.damencnc.com/en/tools/cutting-tools/milling-cutter/226 That mill, because of the spiral flute, should do a great job in alu. My own single flute that I broke 2 of, was a cemented carbide, straight flute, uncoated and easily resharpened when the cherry I was cutting started burning. Cherry burns very easily when being machined, often demanding sharper tools than the carbide for wood working are when falling out of the package they are sold in. There, the need for resharpening a brand new bit is very real. Whats the current dollar/euro rate? 40 & change for that 8mm seems a tad high, but not knowing the money rate... Working in alu, mill life will be extended a lot, as much as 10x, if you do not allow air access to the cut. This is best done for non-enclosed machines, with a mister that throws a mist of something like safflower oil directly at the cut so that the cut surface is oil coated and sealed away from the oxygen in the air, helping to prevent the formation of alu oxide on the cut surface. alu is a VERY reactive metal, oxidizing(burning) literally microseconds behind the edge of the cutter. The air driven mister, if adjusted, only uses perhaps an ounce or 2 of oil an hour in order to keep things wet enough seal the surface, and the air blows away the swarf at the same time so there is minimal re-cutting of loose chips which also leaves a poorer surface finish. But it also puts an oil fog in the air of the shop, requiring trips to the house to soap and water clean your glasses, and a respirator for your lungs. Best would be a housing connected to an out of the building and running, small dust collector, bag optional. I tried the end of the 4" hose downwind of it but that was not a total solution to the oil fog in the air. > I tried googling, but all I can find, is located on the other side of > the pond. Thanks in advance! Others here will probably have different ideas. As a hobbyist I get away with stuff that OSHA would cite me for in a heartbeat if I was trying to run a commercial shop. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> "Now this is a totally brain damaged algorithm. Gag me with a smurfette." -- P. Buhr, Computer Science 354 I was taught to respect my elders, but its getting harder and harder to find any... ------------------------------------------------------------------------------ The Go Parallel Website, sponsored by Intel - in partnership with Geeknet, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials, tech docs, whitepapers, evaluation guides, and opinion stories. Check out the most recent posts - join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
