Rigid Tapping, multiple holes.

How do you guys run a tap, in a cnc machine. Do you guys do the M01 after the tool change, and apply cutting oil to the tap? OR do you guys just let the coolant flow? Do you guys run the tap all the way through on through holes( or to depth on blind holes ) or do you just start it in the hole, then finish it manually?

I am curious, because, in our shop, the senior guys, they just use the coolant, and start the tap, maybe 2-4threads deep, then finish it manually( blind or through holes). In my opinion, i think the entire tapping operation can, and should be finished via, cnc.

Do you guys feel that there is more risk of a broken tap, if you run the tap thru ( or to the desired thread depth )?

On a mutli-hole tapping operation say, 8 holes..what do you guys prefer to do?

what brand of spiral fluted taps do you use? Carbide/HSS/HSCO??

What is your method of deburring, the slight burr that results after the tap has went through, keeping sure that the thread will remain undamaged??

I personally, think that the senior guys at my work are too old school, and when i am on the off-shift, and when im the only guy whos running the vmc's, i run the tap thru, and i insert an m01 after the tap is in the spindle, and i apply either bandsaw wax lube, or syntheic grease, and i adjust the coolant pressure, so its low enough to not wash away the wax/grease but high enough so that it will provide sufficient cooling to the area.


I am very curious on this subject, and would appreciate any thoughts comments, on this situation, i am open to positive criticism, and I welcome your thoughts/Insights!

Thanks!

Hawg,
It somewhat depends on the material. But for the basics I tap full depth with coolant. If it is through then I just deburr anything that shows up on the back side. When using coolant for tapping make sure you concentration is up in the 5-10% range.

I mostly us OSG thread formers. But also use cut taps as well. No particular fave for run of the mill stuff.

If it is something like tool steel then I will apply MolyDee manually.


Then there are the times when I just do my tapping offline with my air tapper.

Your old guys obviously do not trust these new fangled CNC machines. Rigid tapping is the bees knees as far as I am concerned. And yes cut the whole thread in the machine; why hand tap at all? We've never broken a tap while rigid tapping......

For aluminium or softer steel we just leave the normal coolant running. For tougher stuff like stainless we will stop the machine to apply the cutting oil/wax.

I like the HSS-PM taps if using a cutting tap but for ductile materials, form tapping is definitely the way to go. You get better quality and stronger threads, no swarf in the hole, you can run them twice as fast and they are actually stronger as there is no flute. You do need more spindle HP though.

Chamfering/countersinking is done before tapping; if you get the depth right there should be no deburring necessary.

Regards,

Mike.

Never broken a tap while rigid tapping?


IMO this is a part specific question. If it is cheap material/production werk - by all means you should tap through with coolant blazing - no M1's.

On the other end - if you have a block of tough material that you already have a bunch of time into, especially with blind holes that will make extraction even tougher - then starting the holes a few turns and finishing offline would be a wise choice.

Everything in between is a coin toss.

Doo yuh feel lucky?


-----------------

Think Snow Eh!
Ox

Just like Ox said, depends on your application and balls.
If the tap wants to break, rigid tapping will accomodate it as well as any other method.
Also, if the thread is through, how do you chamfer the back side first? If you chamfer the back side later, how do you make sure you didn't put a burr ino the thread?
Do you have infinite trust in spiral fluters in blind holes? I don't, at least not in anything other than AL? Threadformers will help up to a certain size, above that however you got to make your choice.

As for the application of the lube.... Haas's MOM option is on level with the invention of the wheel, aspirin and sliced bread combined.

SeymourDumore said:

As for the application of the lube.... Haas's MOM option is on level with the invention of the wheel, aspirin and sliced bread combined.

Click to expand...

And would you believe that they're thinking of dropping it? I guess it hasn't been a big seller. I'm not sure why.

Donkey Hotey said:

And would you believe that they're thinking of dropping it? I guess it hasn't been a big seller. I'm not sure why.

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Let's see. It consists of a $2.50 Aluminum block, $10 worth of vinyl tubing, a reservoir and a small electric pump. It all mounts onto the P-COOL head and the control already knows about how to program it.
Dropping it would be..... Dumb as shiit and utterly unexplainable, not even with the minimum per month policy of Haas.
Perhaps marketing it a little better make sense.
I for one would have gotten it no matter what, but it was in the VOP package I purchased anyway.
Can tell you though, 7 threads into a 347SS part used to eat a tap after 3 parts, OR F-d up the part beyond repair. That was before MOM.
Now, I get the run of 25 - 30 parts completed without ever changing taps or screwing up a part.
Ditto for 3/4" deep blind M3 threads using a threadformer. Before MOM there was not enough lubrication from the coolant, and the taps started ripping out threads OR breaking beyond .500 depth.
With MOM it has NEVER happened in over 10,000 holes.

Perhaps they need to display the thing during shows, and do it on TL-s with open frame using some fluorescent liquid so the great unwashed can actually see what's happening.
That option is downright AWSOME!!!

I like to use Emuge tap fluid when tapping anything but aluminum. Turn off coolant. I will raise the R plane on the tap cycle to give me more time to apply the tap fluid. You can also reduce the rapid speed to give more time. Usually I will tap to the full depth needed. When using a spiral flute, watch for chips wrapping around the tap. Air gun in one hand, tap fluid in the other.

Don't go cheap on tap quality! For blind holes, I like at least .3 clearance in the bottom. If you don't have the clearance, grind the point off the tap.

For smaller threads, go with the biggest dia tap drill size I can get away with.

Ken

knc said:

Iwill raise the R plane on the tap cycle to give me more time to apply the tap fluid. You can also reduce the rapid speed to give more time.

Click to expand...

Have you ever considered the MOM?
Do you know what it does and how it does it?

Not a reflection on you, rather on Haas and your local HFO's hot-airvent ( aka salesfella).

No R-plane elevation, no poking around with a brush, no speed reduction... nada.

SeymourDumore said:

That option is downright AWSOME!!!

Click to expand...

That's a glowing review if I've ever read one.

It wasn't available when I bought my machine. Where do the other components mount (reservoir & pump) and how is it activated? Do they use an M-code? Is it a one-stroke pump or continuous flow that just runs short duration (I'm wondering about drooling when it's off)? You're the first person I've heard from that has it and I think it's relevant to this thread.

I'd be interested in adding it to my machine now or in the future. I wonder what the retrofit would cost.

Not a Haas user (Sharp), but just finished 800 holes, 1/4-20 in AL 6061-T6.

1200 RPM
Rigid tapping cycle
OSG forming tap
0.228 drilled hole to start
flood coolant (only), Rustlick 370R

Looks like I could have done 8,000 of them, easily.

Try it, you'll like it. Tap air first.

Donkey

While I don't know if it is available as an add-on, I can't think of a reason why it would not be.
The reservoir is nearly identical to the standard waylube reservoir, except it has a single acting piston pump. It has a 1/8 dia tube coming out and routed to a small Al block that is bolted onto the nozzle of the P-cool, so it moves along with it, pointing to EXACTLY where you want it to.
The programming is dirt simple and done in a few different ways.
with M101, it can be told to use the squirt whenever a hole type canned cycle is encountered. ( G76,77,81,82,83, 84 etc etc). Whenever these cycles are called and M101 is active, there is a I(nn) length of squirt at each time the tool is at the R-plane.
Meaning, with multiple holes every time the machine moves to a new X/Y location AND moves to the R-plane, there will be a squirt of oil.

The other way to use it is with M102. It now replaces the standard M08 flood coolant and can be used at any operation.
On the M102 line you specify I (On-time ) and J ( Cycle time ), which results in a I - length of squirt at every J interval while in a cutting motion OR until M103 (MOM-Cancel) is encountered. Quite nice when you don't want to flood something sensitive.

The nozzle produces a very fine stream, directed right at the tooltip ( programmable by the P-cool's setting) and is strong enough to actually knock off the chips from the tap.

Oh, as far as the actual programming, here is a quick example:

T1 M06
G00 G43 H01 D01
S1000 M03
M102 I.5
G00 X0 Y0 Z1.
G83 G98 R.05 Q.25 Z-.5 F5.
X1.
X2.
X3.
G80
M103
G00 G49 G53 Z0

Every time the drill gets to Z.05 ( R-plane), it gets a 500ms ( I.5 ) squirt.

Have you ever considered the MOM?
Do you know what it does and how it does it?

Not a reflection on you, rather on Haas and your local HFO's hot-airvent ( aka salesfella).

Click to expand...

Over 99 percent of my current work is aluminum aerospace, coolant works great.

For the other 1 percent, I can get by with a little emuge and reduced rapids

Ken

SeymourDumore said:

While I don't know if it is available as an add-on, I can't think of a reason why it would not be.

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Hmmm...I just looked at their site: $1,195 for the option and:

Minimum Oil Machining System for VF-1- VF-4, VM-2, VM-3 and all EC machines. Can only be installed on machines with LCD with version 13.11 software or higher.

Click to expand...

That may leave me out--at least as far as the software features. Yes, it sounds like they did the integration the right way. I like that it can re-shoot the tap at each R plane.

I could modify my Mastercam post to put out an M-code with the tapping cycles. It could do similar with a one-shot pump and reservoir right on the spindle housing. The plumbing and p-cool bracket are a no-brainer.

To save starting another thread on rigid tapping, anyone know the maximum rpm a VF4 can take in rigid tapping mode, currently running 1200rpm on a 3/8-24 forming tap in 6082 T6, but have recieved some new boron-nitrided taps that can run at 2500rpm (or so the salesman says, soon find out...).

Not sure what the machine will take before going out of sync. though, it's a through hole, 20mm deep, flood coolant through the Pcool, any ideas?

A whole 'squirt' of tapping oil sounds messy? Is it?

I just bought a metering pump on eBay so I can make a MOM system for my VF-2. It's adjustable for duration and stroke length. I figure I can make the squirter block and the plumbing, then run this from an M-code.

I don't do steel right now but based on this thread, I can see the advantages that MOM would offer.

Hu, the mess thing depends on the lube itself.
The OEM supplied lube is Unist CoolLube 2210. It has the viscosity very comparable to water. It also does not leave an oily film.
I have all but switched to Unist on the Bridgeport off-hand applications as well because it cleans up quite readily. For the real PITA stuff I keep AccuLube around as it is a little better lubrication for tapping. Unfortunately it is one miserable thing to clean up immediately, nearly impossible after a few days.
Not so with Unist and it also seem to be mixing quite readily with the coolant as well.
Also I usually leave the tapping as the very last operation, so the oil does not get washed into the machine by turning the coolant on again.

Donkey, that should work. All you need is immediate full pressure so when it's activated it won't start pissing first before it develops the full pressure.

SeymourDumore said:

Donkey, that should work. All you need is immediate full pressure so when it's activated it won't start pissing first before it develops the full pressure.

Click to expand...

It's not just a pump; it's a laboratory type, metering pump. It supposedly has extra fine control and since it's a single-stroke piston pump, it should have instant pressure (60 PSI IIRC).

It depends...

It depends on the work depth, cutting speed, material and the coolant that you are working on and working with. For aluminum, with rigid and high-speed machine tapping and with missle-lube coolant, no problem. However with heat-treated steels, you may use a thicker oil base hard-cut coolant or for critical female threading work, you may try to consider thread hobbing. In any of the situations stated, it might be an advantage if you incorporate tool life management in your CNC operations. Hope I had given you some input.