Tapping Head

Finally broke down and bought a cheap #0-1/4. I find myself tapping lots of 10 -32 holes lately. Anyway, I was wondering if tapping speed is like drillling speed in that too slow can produce poor performance in some materials just like going too fast can?

Reply to
Bob La Londe
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I did a fair bit of small tapping (4-40 to 10-32) with a Procunier "CNC" tapping head. I started out slow, and eventually worked my way up to around 1000 RPM. That was mostly in aluminum. I now do rigid tapping on the mill, and also do it around 1000 RPM. Results are great, and the taps seem to last forever. I use "alum-tap" as a tapping lube, it is exceptional!

Jon

Reply to
Jon Elson

No negatives from the slower than formula tapping speeds? I'm conservative.

Reply to
Bob La Londe

Use cutting fluid liberally and your conservative approach probably won't cause a defecit in your cutting tool budget.

Reply to
PrecisionmachinisT

I have a feeling the threads look cleaner at the higher speeds, but I really have no way to know for sure. I certainly can't do 2-56 taps at

10,000+ RPM.

Jon

Reply to
Jon Elson

If you are cutting at 2,000 RPM, that is 33 revolutions per second. If it takes 0.5 seconds to stop the spindle, this is roughly seven revolutions beyind the point where spindle just starts decelerating. Quite a lot of overrun.

For now, I tap everything at 500 RPM.

Largest I tapped was 1/2"-13 in aluminum, at 500 RPM. The Bridgeport Interact 2 did not even blink.

i
Reply to
Ignoramus22792

Thanks guys. I was thinking something like that. Se the HF DP at a moderate speed and leave the tapping head in it all the time. Even at 500 RPM its so much faster than hand tapping that I doubt I'll worry too much about it anyway. I also ordered some spiral flute taps in the sizes I figured I'ld use most.

Any tell tail signs that tell you its time to retire a tap before you ruin a work piece with 20 hours of machine time invested in it?

Reply to
Bob La Londe

Bad tapping envy here.

Most has been #10 but they run down to #6 (and several broken taps).

Reply to
CaveLamb
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Makes sense.

Depends on the tapping head you have. The TapMatic 30X for example, has a torque limit clutch. The proper way to set it up is to set the torque to minimum, then (with a brand new tap, and the same workpiece material that you will be tapping), increase the torque until it just provides enough to tap on through. Leave it at this setting (for this size of tap and workpiece material), and when it starts slipping again, it is telling you that the tap is dulled enough so it is time to replace it. I don't know whether the Procunier tapping heads have the same feature -- and only *some* of the Tapmatic ones have that. My smaller one (up to #10 taps) has the feature, the larger one (good to at least 1/2") does not, but had an adjustment to how much travel before the dog clutch releases -- for when you are tapping shallow blind holes. I wish that both heads had both features -- but I've got to live with what I got for cheap prices. :-)

Enjoy, DoN.

Reply to
DoN. Nichols

Not that this is helpful except for general information purposes, but the SPD series (3,5,7 and 9) do not have a clutch.

Never had a problem with them, but I really like your description above on how to set the machine so I may look into those other heads a bit more now.

Regards, Joe Agro, Jr. (800) 871-5022

01.908.542.0244 Automatic / Pneumatic Drills:
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Spindle Drills:
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V8013-R
Reply to
Joe AutoDrill

Well, description of this head doesn't say anything about a clutch so I guess it doesn't have one. I'm not expecting too awful much for a yard and a half delivered though.

Reply to
Bob La Londe

Useful information.

Hmm ... that would require the operator to be a bit more observant when running a bunch of taps in parallel, since I don't know what would happen when one started slipping and the other five (or whatever number of spindles you have) kept feeding. :-) I guess that they would stop fairly quickly when the dog clutch disengaged, but the operator might not notice that he had not reached the full depth, leaving a problem for inspection to catch.

Enjoy, DoN.

Reply to
DoN. Nichols

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If it is a Tapmatic, the clutch (if present) takes the form of a knurled ring at the top, and a white band partly covered by the top exposing a spiral list of numbers (relative torque -- not to any particular units -- or even to the tap size number. Just something to remember about where you had it set last time as a starting point.

Enjoy, DoN.

Reply to
DoN. Nichols

In cases where this might be a problem, we put the tapping head above the multiple spindles:

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Reply to
Joe AutoDrill

O.K. In that case, you would need a stronger tapping head to handle the extra torque which the four taps in parallel would produce. And -- I suspect that it would be a bit less sensitive to a single tap dulling, so you would want to replace all four taps at once when it started to slip.

Enjoy, DoN.

Reply to
DoN. Nichols

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