deep hole drilling

Depending on how much you want to spend on this job, you can get a collet-style tool holder that should go onto your machine with a rotary union to use coolant-thru tooling.

Well, ahm certainlyl no 'spert, but my first strategic thought was to do them round-robin style, mebbe 1-2" per hole, to at least avoid local heating. Shouldn't take that much longer either.

I do drilling this way:

L200 ( hole pattern) x0y0E1 x1. x2. x3. Y1. x2. x1. x0 Y2. x1. x2. x3. etc. m17 m30

Note the next row begins where the previous one ended, to minimize air travel. Then

G83 -------- z-1.L0 The L0 keeps from drilling the first hole twice L201

G83 ------- z-2.L0 L201

til you reach z-6.75.

By the time you get back to the first hole, it should be cool. Essentially each new drill cycle is a new peck. What those pecks should be is another story. Then, of course you can peck within each drill cycle.

You also have the option of sharpening the drill between each new drill cycle, as well.

One problem tho is you don't want chips falling back in to previously drilled holes, so you may want to pause and blow s*it out pretty good, or have a really good stream of coolant blasting straight down, one hole ahead or sumpn.

You can also do blocks of holes in a macro, but it proly isn't worth figgering out here. For hundreds of holes, mebbe.

Holy s*it, $80 for that drill! Good gawd....

I think someone here posted recently about carbide tipped drills, as well. Give yer local supplier a shot at pricing this. MSC, McM, et al have markups of 2-300%. iow, what you pay them $3 for you can get for $1.

Hole patterns in subroutines is esp. efficient for the spot/drill/tap process. Using Lxxx, you cain't make a mistake going from spot to drill to tap. I use Lxxx for almost everything except one single x0y0!

PV, I don't have a Fadal, so the L### means nothing to me.

I can do a G82 spot drill maybe 2 or 3"" deep, then go with a G83 peck till I hit bottom.

Holes are all in a striaght line down the length of a long bar.

That $80 drill says it's good for 15X D without pecking so I should be able to go Z-5.625 then start pecking to finish it off.

Flood coolant should avoid the part heating up, it is a 200 pound plus peice of steel.

Thank You, Randy

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The L201 etc is just a subroutine "call". You proly have some equivalent. Just makes hole patterns more manageable.

The g83 in Fadal-speak has a variable peck ditty, so your pecks get successively shallower as the hole gets deeper.

Fanuc, M98 sub routine call, M99 sub-routine return

G83 peck cycle with fixed peck and full retract to R plane.

Thank You, Randy

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Randy, I would center drill, drill as deep as possible with a parabolic jobbers drill, and then switch to the extra long drill for the final depth.

I would start around 600 RPM and .006-.008 feed per rev.

On deep hole drilling I don't use the canned peck cycle because the pecks are too small at the start and too big at the deeper depths.

Here is a sample program of a hole that I drill in alum. The hole has been pre-drilled 1 1/2" deep with a jobbers drill. Drill I use is a Titex parabolic flute. Part is about 10'' long and gets drilled from both ends to create a thru hole. Miss match on the holes is about .010, but not a problem as air is blown thru for cooling.

Best, Steve

T3M06(# 25 TAPER LENGTH G00G17G40G49G80G90 M03S5000 G54 G00G43Z.1H3M08 G00G90G54X-.8165Y-.1217 Z-1.45 G01Z-2.0F12.0 G0Z-.4 Z-1.9 G01Z-2.4 G0Z-.4 Z-2.3 G01Z-2.8 G0Z-.4 Z-2.7 G01Z-3.2 G0Z-.4 Z-3.1 G01Z-3.6F10.0 G0Z-.4 Z-3.5 G01Z-4.0 G0Z-.4 Z-3.9 G01Z-4.2F6.0 G0Z-.4 Z-4.1 G01Z-4.4 G0Z-.4 Z-4.3 G01Z-4.6 G0Z-.4 Z-4.5 G01Z-4.8 G0Z-.4 Z-4.7 G01Z-5.0 G0Z-.4 Z-4.9 G01Z-5.2 G00Z.1 X-.1275 Z-1.45 G01Z-2.0F12.0 G0Z-.4 Z-1.9 G01Z-2.4 G0Z-.4 Z-2.3 G01Z-2.8 G0Z-.4 Z-2.7 G01Z-3.2 G0Z-.4 Z-3.1 G01Z-3.6F10.0 G0Z-.4 Z-3.5 G01Z-4.0 G0Z-.4 Z-3.9 G01Z-4.2F6.0 G0Z-.4 Z-4.1 G01Z-4.4 G0Z-.4 Z-4.3 G01Z-4.6 G0Z-.4 Z-4.5 G01Z-4.8 G0Z-.4 Z-4.7 G01Z-5.0 G0Z-.4 Z-4.9 G01Z-5.2 G00Z.1 G55X-.8165Y-.1217 Z-1.45 G01Z-2.0F12.0 G0Z-.4 Z-1.9 G01Z-2.4 G0Z-.4 Z-2.3 G01Z-2.8 G0Z-.4 Z-2.7 G01Z-3.2 G0Z-.4 Z-3.1 G01Z-3.6F10.0 G0Z-.4 Z-3.5 G01Z-4.0 G0Z-.4 Z-3.9 G01Z-4.2F6.0 G0Z-.4 Z-4.1 G01Z-4.4 G0Z-.4 Z-4.3 G01Z-4.6 G0Z-.4 Z-4.5 G01Z-4.8 G0Z-.4 Z-4.7 G01Z-5.0 G0Z-.4 Z-4.9 G01Z-5.2

AND, you can put this non-canned cycle into a kind of "can", by putting it into subroutine, and calling that. Then you have super-control with peck depths, and, as you showed, feeds as well. Also rpm, iffin you wanted to vary that with depth.

The only problem, from a programming pov, is that now you have to call this thing 64 times, for each hole position, as opposed to issuing one L201(with all the hole positions) under a G83. No real biggie, tho, given the super-control.

Isn't 600 rpm kind of slow, tho?

Proc, I start out at what Precision Twist recommends and work up or down depending.

Best, Steve

There are coolant injectors for this situation.

for some examples see:

Unka' George [George McDuffee]

------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).

Might be worth getting ahold of OSG & ask them about these....

Nice drill but pricey. The 3/8 drill that the OP needs lists for $246.43

Best, Steve

Thanks for all the replies so far.

Ive spoken to PTD and been to the Guhring web site, neither recommends coolant thru, both recommend a standard drill, not parabolic and not cobalt, just plain HSS.

Per Steve's sample I'll have to write a drill routine and either cut and paste it alot or make it a sub.

PTD recommends pecks of

I've drill aluminum manifolds similar to Steve's but mine were 18" long with 11/32 and 7/8" thru holes. Parabolic worked great.

Thank You, Randy

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Super Cool, yo.

IOW, through-coolant is inferior to flood? How can that be? Unless they are saying that the drill design associated with thru-coolant drills is not so hot.

I wonder if it's the rigidity of the drill as they preferred a standard drill over a parabolic one? Parabolic drills are very bendy, and coolant feed are weaker than because of the coolant holes?

Guhring phone tech says use the series 618 cobalt parabolic drill at

Thank You, Randy

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"Proctologically Violated©®" wrote in news:4a92944b$0$31263$ snipped-for-privacy@cv.net:

Hey....takes money to make money. I just received my 2x - $851 each end mills I've been waiting 10 freakin days for. $80 drill is nothing if you can get it down to >$0.05/hole