Buying the Fadal mill

I posted a while back that I might be buying a Fadal mill and running it from a phase converter. Well, I'm buying it. I'll write the check
tomorrow. It's a model VMC-15 and has rigid tapping so I guess I'll need that parameter changing info. Also, just what is the advantage of rigid tapping over tapping heads? Thanks, Eric
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Don't use a shitty out-of-the-box converter (even name brand), as they use start caps that are never switched out, causing a wild leg that can be 30 V over line V.
Separate the start caps from the running caps, which will be lower value caps between both L1-L3, and L2-L3 (L1-L2 = line).
Also make sure the voltage taps on the Fadal are set for your local voltage.

What year, whadja pay?? What's yer location?

There are *complete* online manuals, good qual. pdf's, I think from MAG. *Identical* to the hard copy, ceptin now you can search'em. Free.
Tapping heads on a drill press? Their advantage is torque control, for less breakage. Don't know much about other tap methods on VMC's.
But the rigid tapping is fast, clean, accurate, you'll be spoilt forever. Also, I believe rigid tapping can handle roll taps better, which I now use on alum almost all the time. I'm rigid tapping as we speak. :)
Post to alt.machines.cnc (what's left of it), and also the PrecisionMachinist forum, which has forums in various categories. No Fadal forum per se (iirc), but lots of fadal users there.
--
EA






> Thanks,
> Eric
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On Mon, 14 Nov 2011 23:38:13 -0500, "Existential Angst"

Year 1996, $18,500, comes with4th axis, Whidbey Island WA. The phase converter I'm runing is a good one that has proven itself for years running CNC machines. How is rigid tapping faster? Do you program the machine to back out faster than going in? As far as form taps go, I've never had a problem with them being used in tapping heads. Eric
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On 11/15/2011 10:41 AM, snipped-for-privacy@whidbey.com wrote:

Rigid tapping.. Once you use it you'll love it. First, most machines with rigid tapping will retract faster than when they go in, this is normally a setting in the parameters. Second, you can re-tap a hole because of the machine knows the clocking of the spindle. This comes in really handy when you tap a large number of holes and think you went deep enough but find out that you didn't. But you don't want to do this if your using a floating holder. You must use a rigid setup to do this.
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I noticed this just today running the mill and using rigid tapping for some pipe threads. All the burrs at the entry of the holes occurred in the same place. Then I thought about it and realized that the timing is going to be the same on every hole. Eric
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Hopefully low hours on the machine, but hard to tell. The 4th axis is Da Bomb. Mine is very heavy (on a fadal 3016), so I keep it permanently hoisted inside the cabinet on a winch, so mounting it is easier for me by myself than for two people with all kinds of pneumatic tables in a trad'l shop.
Whidbey Island WA. The phase

Well, check the generated leg. If it's 20+ volts above line, then you've just been lucking out, and should separate the start caps from the run caps, and tune the run caps.
How is rigid tapping faster? Do you program the

Hmmm, I don't, but I'll have to check the retract thing out. I meant to years ago, never got around to it. Or I did, and it wasn't supported. I'll check again.
Overall, it's faster cuz you just program in spot, drill, tap with one hole pattern in a subroutine, and all that tnik said -- peck tapping, in essence. And, if you want to get real sophisticated, thread cutting, which these fadals don't support as canned cycles, so you'd have to use software or program your own cycles, as the machine will helically interpolate, if it has the CS-88 controller.
As far as form taps go, I've

Well, they require higher torques, and the fadal should be able to handle up to mebbe 3/4" with not much trouble.
--
EA


> Eric



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On Tue, 15 Nov 2011 11:18:05 -0500, "Existential Angst"

The phase converter voltages are very close. Fanuc controls, especially the older ones, are quite sensitive to over or under voltages on one leg. The machine is in a friend's shop now. He has to sell the machine so I'm buying it. Today I was running a job with both a pipe tap and thread mill. So I guess it must have the right kind of control for thread milling. And the 4th axis is really nice. But at 165 lbs I'll be using an engine hoist to put it in and out. Eric
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On 11/14/2011 09:59 PM, snipped-for-privacy@whidbey.com wrote:

A big advantage for me is I can use combination drill-taps and be sure they start the hole accurately without spotting, drilling, then tapping. I have used a tapping head before, but it is a long stack out of the spindle, and there is some free play in the tap holding end, so it doesn't guarantee accurate positioning of the starting hole.
If this machine has an ATC, that may be less of a concern, although the combo drill-taps are really fast if they suit your material thickness.
Jon
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Jon Elson wrote:

For through holes...
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The main advantage of having rigid tapping is that it allows you to use standard drilling collets and chucks instead of having to buy a bunch of additional specialty tooling that is only useful for tapping.
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On Tue, 15 Nov 2011 17:16:48 -0800, "PrecisionmachinisT"

So all the compression/tension tap holders and collets I'm also buying are not neded? I can just hold the taps in ER collets for example?
Eric
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On 11/16/2011 9:57 AM, snipped-for-privacy@whidbey.com wrote:

You can and we have before, especially when we didn't have a tap holder in stock. But we have found out that it's much safer to use a rigid tap holder. Least if its in a tap holder, you KNOW the tap isn't going to spin. Plus we have a bunch of tap holders anyway for the machines we have that don't have rigid tapping.
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I use my TG100 collet holders for rigid tapping. Werks grate for 1/2 and down. I spun the tap with bad results on 5/8x11 in 4140.
Karl
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Well, if a tap is going to spin, it almost always will spin on entry and on reversal it will come back out of the part just fine and so whether or not it breaks off instead of backing out is largely dependant on how far it can be shoved upwards before bottoming out in the collet, and I would much rather have the tap spin and ruin a collet than to have it break off and fuck up an expensive part but even then it's still kind of a crap shoot.
That said, even though there is rigid tapping on two out of our three Fadals, I don't use it simply because most of our workload repeats...which means that I would have to either edit at the machine, produce a duplicate program for pretty every freakin job that involves tapping, or maintain a list of jobs that can't run across the machine that lacks the function ( and try to schedule production accordingly ) all of which IMO would unnecessarily complicate things.
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You would still do well to buy at least one rigid or floating chuck and a handful of adapters to use wherever it is advantageous to drive from the square tang--but mostly they are only needed for larger diameters...say 1/2 or so and above and in tough materials like stainless where high torque requirments might otherwise allow the tap to slip.
That said, you'll usually also be able to better control thread tolerance limits with tap adapters because they typically allow for the tap to wiggle a slight amount on the radial axis and so it tends to center itself instead of being horsed into the material, producing a loose hole...
--something to consider for instance if you are doing a aircraft work in aluminum where 3B fits are the norm.
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On Wed, 16 Nov 2011 11:10:22 -0800, "PrecisionmachinisT"

Thanks everyone for the answers about tapping. Since the machines come with tap adapters already I'll continue to use them when I can but if a job comes up with more tap sizes than I have adapters I'll run the smaller taps in regular holders. Especially since I almost always try to put class 3 threads in or on whatever I'm machining. Since this will be my first mill with a toolchanger I need to learn as much as possible about optimizing tooling. Eric
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Sounds like a plan.
A pretty good method is to have some larger collet chucks say for instance in the DA180 and/ or TG100 series and then buy spare collets in the 3/4 and 1 in sizes for them so that if the need arises where you need to run a whole bunch of small drills etc, you can put straight shank extension chucks in them that your smaller collets will fit into.
The logic behind this is because oftentimes where you have several different sized holes in a part and they are all over say...5/8 or so in diameter, you might just as well to drill undersize and interpolate with an endmill rather than to try and stock your crib with a myriad of the large drill sizes in attempt to cover every possible contingency..
--Yes it might take a bit longer to interpolate but oftentimes it's more expedient than to purchase drills if doing short run work and also considering that since the VMC 15 has no mechanical reduction, it's torque is seriously lacking at the lower rpm ranges and so you can run into problems with spindle stalling especially when running large HSS drills in alloy steels.
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On Wed, 16 Nov 2011 14:12:12 -0800, "PrecisionmachinisT"

The torque problem is one I deal with running parts on the lathe. I have one lathe with no gear reduction but a 15 hp spindle. I have another with a 10 hp spindle but it has a gearbox that goes all the way down below 200 rpm. So it gets used for big stuff or when using big drills on SS. It's nice that the Fadal interpolates round holes. This is something I'll need to get used to thinking about. Eric
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