Cutting with carbide end mill

I've read that carbide end mills don't like thermal shock, so my spray bottle is
out of
the question.
Eventually I'll get a flood coolant but I need to mill something now.
My question: can I ruin my expensive carbide end mill by cutting dry O-1
annealed steel?
Thanks,
Alex
Reply to
Alex
Loading thread data ...
bottle is out of
annealed steel?
You could get by nicely by just applying cutting oil with a brush. An acid brush is the thing to use, dipping into a small can that is well filled with oil. The hollow handle of the acid brush will hold a fair amount of oil and keep the end mill lubricated well enough to prevent problems. It stands to reason that you might want to keep the speed down so it doesn't cut too hot-----if you're cranking out pale blue chips you're likely to have problems, a sure sign of over heating. Those of us that do not operate CNC machines tend to work that way routinely----it's the way we were trained.
Harold
Reply to
Harold and Susan Vordos
Does that apply to lathes as well Harold :-
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Mark Rand RTFM
Reply to
Mark Rand
Worst enemy of carbide is lack of rigidity.Vibration, bad chatter are some signs of that.
You can load up the end mill to where chips coming out are tan in color, assuming motor can handle depth/IPM (feed) of particular cut.
Assuming 1/2 - 3/4 end mill, you should be able to remove close to .080 per pass, with 1 HP motor. For your application, you should able to crank out that integral knife frame in 1 hr or so, plenty fast.
My advice is to keep the bar rectangular for as long as possible. Assuming you have parallels and the vice has wide nuff of jaws (4"or more), you won't have trouble holding the piece.
You'd need to reduce DOC as metal gets thinner, as it will flex away under cutting pressure.
Be careful as you side mill stuff with smallish chip load (say, less than 10 tens) - the chips will be coming out in a form of tiny needles . If you are dry milling , these will land everywhere, including your hands. I wear a thin latex glove on the hand closes to the spindle
Alex wrote:
Reply to
rashid111
the short catfood can and an acid brush are industry standards for cutting, drilling, tapping, milling.
Some machinists may get a wild hair and turn their own fancy oil holder out of a chunk of stock, putting on fancy fins and all sorts of doodads..but you will find the cup o oil and an acid brush in virtually every commerical shop.
Gunner
"Deep in her heart, every moslem woman yearns to show us her tits" John Griffin
Reply to
Gunner
I tend to run blue chips a lot. Shrug..but then with carbide tooling...thats right in the "geterdone" range
Gunner
"Deep in her heart, every moslem woman yearns to show us her tits" John Griffin
Reply to
Gunner
snip----
There's a serious difference between an end mill and a lathe tool----where lubrication to aid in discharging the chip comes into play. Chip welding is an ongoing problem with end mills, and the condition spells almost instant death, very different from turning operations. That's my reasoning in suggesting running the cut cooler-------if blue chips are coming off, the oil will be smoking a bit on the heavy side and will be unlikely to be doing the job required. . Don't get the idea was speaking in general------I'm very adept at roughing and blue chip making on a lathe-----I just know that it can be trouble with an end mill. :-)
Harold
Reply to
Harold and Susan Vordos
Rashid,
do you mean to that I have to leave "meat" on all four sides? Like on this pictures -
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Alex
Reply to
Alex
snip-----
As I said, machinists are trained that way--------it's more than adequate, particularly for manual machining. The only real negative is that the volume provided isn't generally enough to cool-----but it does lubricate, which in and of itself tends to help keep temperature down.
Harold
Reply to
Harold and Susan Vordos
And I used to do the same, until one day one of those brushes wrapped itself around a 1/2 or 3/4" end mill and was shredded between tool and work, showering me with triangular shards of extremely sharp metal, and finally throwing the spiral remnant of the handle at me like some kind of mechanical porcupine.
Since then, I've taken to using old toothbrushes. My brood goes through quite a lot of them, so I seem to be in perpetual supply. They last a LOT longer than the typical acid brush, cost me essentially nothing, and are both less likely to get wrapped around the cutter and less hazardous if they do.
Jon
Reply to
Jon Elson
I can't see how I can clamp a piece like this(what I have right now):
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a vise.
Next time I try to mill I'll leave extra "meat" on all four sides for more rigidity.
rashid111 wrote:
annealed steel?
Reply to
Alex
Alex
"Glaza boyatsa, a ruki delayut" .
"Hands will accomplish what eyes are afraid of" . A Russian saying.
You're overthinking it.
- start with a precision ground stock, .5 x 1.5 x 9" (18" cut in half, a good length for an integral).
- vice up the "handle end", resting on parallels, mill out - flip, mill out - now, vice up the blade end, rest it on parallels and mill one side - flip over, use parallels, slightly taller to account for what you milled away in the prev step, to support the blade end again
Done :)
The butt in integrals is usually milled at an angle, for more pleasing appearance. Bolster area is sometimes groved 1/8" from the handle end, for same reason :)
Integrals are always handle-heavy. To combat that, drill out a series of holes in the tang area. Also, butt is usually milled for a strap, it also reduces the weight of the handle area.
Don't go too thin on handle or blade area . Integrals have all these sharp corners that act as stress raiser and with fast quenching steels you might have a problem.
Alex wrote:
bottle is out of
annealed steel?
Reply to
rashid111
===================== It may well be that you can't, at least in any vise you can afford and/or that will fit on your mill.
A vise is simply one very handy way to clamp a work piece for machining, but too often people forget that is all it is.
One of the big benefits of having your own machine shop is the ability to make your own tools and fixtures when an "off the shelf" solution is not available or is too expensive.
The group could offer better suggestions if we knew the approximate dimensions of the piece, the material, the planned operations, and approximate numbers.
In broad outline, you can construct blocks made from aluminum or steel that you can fasten using t-bolts/nuts to the mill table, and then clamp the part to the blocks, possibly with an integral screw or two. Be sure you don't drill thorough the part and into the table!
The downside is that these can be "fiddly" to set-up with a lot of indicator work to get the first part aligned/trammed, but if designed correctly, with work stops, these can be faster than a vise on subsequent parts.
I don't know what you are machining, but generally it is a good idea to have support under the thin sections when you cut the second side to avoid chatter. You don't need anything elaborate, but a block or shim of the correct thickness.
Good luck with your project, what ever it is.
Unka' George [George McDuffee] ............................... On Theory: Delight at having understood a very abstract and obscure system leads most people to believe in the truth of what it demonstrates.
G. C. Lichtenberg (1742-99), German physicist, philosopher. Aphorisms "Notebook J," aph. 77 (written 1765-99; tr. by R. J. Hollingdale, 1990).
Reply to
F. George McDuffee
Not a bad solution to your problem aside from the lack of ability to carry a supply of oil. The hollow handle of acid brushes isn't an accident----it's intended to be the reservoir that dispenses the oil as it's used. That's why I suggested a fairly deep can in an earlier post. You get a larger supply when you dip, assuming you allow time for the tube to fill. That's very essential if you're parting ------where an interrupted supply can lead to a broken tool.
You think an end mill gives you trouble----try catching one in your knurling tool.
Don't ask! :-)
Harold
Reply to
Harold and Susan Vordos
snip--->
The "one" in question would be an acid brush. Interesting things happen when they get caught in the rolls.
Harold
Reply to
Harold and Susan Vordos
================== It all depends on how hard you push the tool. If you use moderate feeds, speeds, chip loads, dept of cuts, etc. and nothing gets hot [no blue/brown chips] you should be fine.
When you calculate your starting machining settings, remember these were developed for the commercial shop where most definitely "time is money," so these are optimized for the lowest total production cost with an operator making 20$ or more per hour, not the longest tool life. The only caution is that you should take enough of a cut to get under any work hardened layer and to get a continuous cut.
Coolants have three real functions (in addition to making a mess and stinking up the place). (1) They cool the work, which is not a problem with low feeds/speeds. (2) They wash the chips out of the cut, which again is not a problem with low feeds/speeds, and which you can accomplish with a solder brush or very small paint brush. [An air gun will blow chips every where, including the bearings, gibs and ways.] (3) When you are cutting some materials, there can be a tendency for a chemical bond anf/or a mechanical bond to form between the tool and the material. Heat can make both problems worse so moderate feeds/speeds again prevent most problems. Cutting oils provide lubrication to reduce the mechanical loading/welding, and additives such as sulfur "contaminate" the surface to reduce chemical bonding [Think of this as an anti-flux for soldering]
Assuming you are cutting steel, I suggest black sulfur lard oil. [technically cutting oil not coolant] As this may be too thick for your operation, it can be thinned a little with varsol or mineral spirits [also kerosine/diesel]. I have had excellent results using only a small container [I use a flat bottom 1 inch pipe cap, its heavy and doesn't hold enough to make too big a mess when I knock it over] with a solder brush, to both apply the coolant/cutting oil and brush off the chips.
One trick is to apply the cutting oil high on the end mill and let it run down as this provides a more or less continuous film. FWIW, I find kerosine/diesel to be ideal for aluminum. WD40 will also work, but an aerosol, even with a straw, tends to create a mess, and you will need a brush for the chips anyhow.
Good luck on what ever it is you are making -- sounds like a fun project.
Unka' George [George McDuffee] ............................... On Theory: Delight at having understood a very abstract and obscure system leads most people to believe in the truth of what it demonstrates.
G. C. Lichtenberg (1742-99), German physicist, philosopher. Aphorisms "Notebook J," aph. 77 (written 1765-99; tr. by R. J. Hollingdale, 1990).
Reply to
F. George McDuffee
Okay, so I'm late and catching up, but Gunner wrote on Mon, 08 Jan 2007 18:27:42 GMT in rec.crafts.metalworking :
This raises an interesting question: what will be the new industrial standard when the cat food people all shift to pouches?
tschus pyotr -- pyotr filipivich "Quemadmoeum gladuis neminem occidit, occidentis telum est. " Lucius Annaeus Seneca, circa 45 AD (A sword is never a killer, it is a tool in the killer's hands.)
Reply to
pyotr filipivich
Not to worry-- I'm sure HD will have catfood cans--empty and clean of course--for 99c ea. Just like they have 5-gal pails for $4.99--the same as the hundreds you have likely already thrown out. Staples sells moving boxes, identical to the 10-ream paper boxes they crush so's you cain't use'em.
I actually worry about a loss of supply of cat food cans. I take milk cartons, and saw off the bottoms. Cut plastic soder bottles, .005 aluminum cans?
Oh, the denegration of it all....
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Proctologically Violated©®

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