[SCzEngrgGroup]

Ray, I'll slow the down feed by 5% from now on.

Beezle - HSMWorks uses only "cycles" for drilling, so I had no choice but to try it. However with a post edit I can now have it do long hand g-code and it works with the numbers I enter for feeds now. I'll probably never use a cycle again - but it works.

Here's the tapping head code I use in HSMXpress:

case "tapping":
if (tool.type === TOOL_TAP_RIGHT_HAND) {
writeln(" (Tap: " + formatComment(tool.description) + ")");
writeBlock(gMotionModal.format(0), zOutput.format(cycle.retract));
writeBlock(gMotionModal.format(1), zOutput.format(z), feedOutput.format(F));
writeBlock(gMotionModal.format(1), zOutput.format(cycle.retract + 0.75), feedOutput.format(cycle.feedrate * 2));
//onDwell(1.0);
writeln("");
}
break;

This goes in the big switch statement in the OnCyclePoint method.

Regards,
Ray L.

[Steve Seebold]

I have tapped thousands of holes on my PCNC 1100 using a Tapmatic 30X tapping head, and the only time I have broken taps is when I do something really dumb like make an X or Y move before I pull the tap out of the hole.

I don't use the M871 tapping cycle. I will always G code my tapping routines, and since I started using a T/C tapping head, I don't use the Tapmatic head any more.

I have tapped holes as small as 0-80 on my machine with no problems.

[kstrauss]

Will you share your T/C Gcode?

[Steve Seebold]

Will you share your T/C Gcode?

Sure, here you go.

S500M3

G0G90X(FIRST HOLE) Y(FIRST HOLE) Z.25 G43H(OFFSET NUMBER)M8

I always start .25 above my part

G1Z- (DEPTH) F14.0625 (10% less than calculated feed rate)
M4
G4P.25
G1Z.25F17.1875
M3
G4P.25

Copy above

Move to next hold

Paste

When I get down to 6-32 and smaller holes, I use 5% increase and reduction, and I have tapped holes as small as 0-80 with form taps.

I will never use a cutting tap when a form tap is available. Every tome I use a cutting tap, I always manage to leave some of it in the hole.

[BAMCNC.COM]

Awesome Ray!!!!

As for the guy with broken spiral POINT tap - those are to be used with through holes only. Form or Spiral FLUTE taps are for blind holes.

[SCzEngrgGroup]

I have tapped thousands of holes on my PCNC 1100 using a Tapmatic 30X tapping head, and the only time I have broken taps is when I do something really dumb like make an X or Y move before I pull the tap out of the hole.

I will never use a cutting tap when a form tap is available. Every tome I use a cutting tap, I always manage to leave some of it in the hole.

I'm suffering from cognitive dissonance trying to reconcile your two statements.... You never "break" (cutting) taps, you just "always" leave pieces of them in the holes? I daresay most of us would call those "broken".

Regards,
Ray L.

[BAMCNC.COM]

lol, I assume he means chips?

[Hirudin]

Seems like it also might be the case that he broke a lot of cutting taps ("I always manage to leave some of it in the hole") then he switched to forming taps and has great success ever since ("I have tapped thousands of holes") aside from a few screw-ups here and there.

OT talk over? Talk about cross-threading.

[MichaelHenry]

As for the guy with broken spiral POINT tap - those are to be used with through holes only. Form or Spiral FLUTE taps are for blind holes.

I'd agree that spiral point taps are preferably used on through holes, but they do work just fine on blind holes so long as the hole is drilled a fair amount deeper than the depth you tap. For 8-32 holes, I've been finding that 0.750" deep drilled holes can be reliably tapped to 0.500" deep in 6061 with a decent tap lube and a tension-compression tapping head at 500 rpm.

Mike

[BAMCNC.COM]

Even if you grind the point off it's still pushing chips down your hole - why get a dental pick, and pick them out when you don't need to?

[SCzEngrgGroup]

Even if you grind the point off it's still pushing chips down your hole - why get a dental pick, and pick them out when you don't need to?

Spiral point taps are stronger than spiral flute taps, so harder to break. They are also often significantly cheaper. It's not always necessary to pick the chips out of the hole. In a blind hole, the chips will often get so tightly packed in, you can just leave them where they are. Rather than keeping a stock of both kinds, I find I can get by with only spiral points.

Regards,
Ray L.

[Beezle]

I bought a few spiral point (form?) taps to try out for blind holes. Someone told me that form taps are great so why not? The spiral point taps I bought look like form taps to me, so I assume that's what they essentially are?

And on the original break, I am trying the Alum method. So far, so good. About half the tap is dissolved at this point.

[Hirudin]

Spiral point, spiral flute, and forming taps are all different kinds.

Spiral flute...


Spiral point...


Forming...
Attachment 255252

Images from McMaster-Carr...
McMaster-Carr

Note how they added in the chips; coming out the top for spiral flute, coming out the bottom for spiral point, and missing (not being created) from the forming tap.

[SCzEngrgGroup]

It's very easy to distinguish form taps from cutting taps. Cutting taps have sharp cutting edges, form taps do not - they are generally a more triangular profile, with rounded corners, and no flutes.

From top down: Spiral Flute tap, Spiral Point Tap, Plug Tap, Form Tap

http://www.metalformingmagazine.com/...-Fastening.jpg

Regards,
Ray L.

[Beezle]

Spiral point, spiral flute, and forming taps are all different kinds.

Spiral flute...


Spiral point...


Forming...
Attachment 255252

Images from McMaster-Carr...
McMaster-Carr

Note how they added in the chips; coming out the top for spiral flute, coming out the bottom for spiral point, and missing (not being created) from the forming tap.

Ah, thanks. So I am using the correct taps for blind holes.

For now, I will probably stick with a spring loaded tap guide and hand taps. Most of the parts I make are one-offs anyway. I don't mind writing a little code for the tapping head, but this has been too much hassle.

[Hirudin]

Yup! Wasting many hours (or days) trying to fix a tap that broke while trying to save 10 minutes can really ruin a day (or week).

[waltpermenter]

It's very easy to distinguish form taps from cutting taps. Cutting taps have sharp cutting edges, form taps do not - they are generally a more triangular profile, with rounded corners, and no flutes.

From top down: Spiral Flute tap, Spiral Point Tap, Plug Tap, Form Tap

http://www.metalformingmagazine.com/...-Fastening.jpg

Regards,
Ray L.

not quite, the 3rd one down is a bottom tap, a plug tap is pointy like 2nd one down. many other taps can be plugs or bottoms too,plugs are pointy.
walt

[waltpermenter]

Yup! Wasting many hours (or days) trying to fix a tap that broke while trying to save 10 minutes can really ruin a day (or week).

yup, keep a set of tap extractors on hand and you could be back in business in a couple minutes.
walt

[Beezle]

yup, keep a set of tap extractors on hand and you could be back in business in a couple minutes.
walt

I have lots of extractors and they do work for some things, but not this one.

[Steve Seebold]

Once you learn how to use form taps in aluminum, you'll never go back to cutting taps.

Form taps cost a little more, but you'll soon see, once you get used to using them, you'll quit using cutting taps.

You need to drill your holes to pitch diameter size, and use plenty of coolant, but you'll soon like the idea of NO CHIPS packed into the bottom of the holes.

You can google form tap drill sizes and get all the information you need.