[dneisler]

I have a large job to run with some 12L14 and I need to tap a 1/2-13 hole. How/what is the easiest way to hold the tap?
I do have the turret and yes I can know I could turn the threads, but I need to use a tap this time.

ER20 tap collet or ?

[cbyrd]

I just use the ER20 lathe holder. Works well.

[dneisler]

Ok I have the er20 holders just no tap collets for it. Where is best place/price to get them?


Sent from my iPhone using Tapatalk

[MichaelHenry]

Any ER holder that will take the tap size should work, shouldn't it? The collets cover the continuous diameter range between minimum and maximum for the collet type so one of them should fit. My 1/2-13 taps all fit into a 3/8-in ER-20 collet.

[wtopace]

Just curious - Does the Tormach lathe have enough power to drive a 1/2-13 tap into steel (even 12L14)?

I would seriously consider single pointing the threads if at all possible, you'll get better concentricity, more accurate threads and not have to worry about stalling the spindle and/or breaking your tap.

This is from HSM Advisor with a 75% thread engagement:

Material: 11L17, 11L18, 12L13, 12L14 Leaded Carbon Steels (150-200 HB)
Tool: 0.500in 1FL HSS None Tap
Speed: 40.0 SFM/ 305.7
Feed: 0.0769 in/tooth 0.0769 in/rev 23.52 in/min
Reference Chip load: 0.0769 in
Power: 1.5HP
MRR: 1.28 in^3
Torque: 26.59 ft-lb
Max Torque: 93.81 ft-lb

[dneisler]

It should my tormach mill will do it all day long with 1.5hp. The lathe is 3hp sh it should but I have not tried it. I am not worried about accuracy as I have +\-.05

[LeeWay]

Tap collets do hold with the square end of the tap as well as the round shaft.
I think they may be a little overkill on a mill because the weak link is the TTS system itself. The lathe will hold the TTS better, so the tap collet is beneficial there.
They are also hot swappable between the mill and lathe which is pretty convenient.
Here is where I buy mine.
https://www.suncoasttools.com/crm/Ve...a#product-list

[dneisler]

That the exact ones I bought. I hope to give this a try this weekend.


Sent from my iPhone using Tapatalk

[dneisler]

Well I gave this a try this weekend using a 1/2-13 TG Tap, FAIL! Spindle Stalled, It made it about 1/2" in of a 1." deep thread, at least I did not break the tap. I was attempting this @ 500 RPM? Was that to slow?

Also, I have to get this working, so what do I need to buy to get this job done. I have nothing to do single point threading currently.

[LeeWay]

I would say it may be too slow. Also you can peck tap for deep holes. I consider that a deep hole.
I don't think there is a lot of torque on this motor at slow speeds.
I tap up to 3/8" with a servo spindle on my Novakon that deep, but only in aluminum. I only use 150 RPM in Mach 3 because that is how my Sheetcam Post is setup. I will be using faster speed when I make the final swap to Path Pilot.
Hole size is pretty critical as well. Depends on how much thread you actually need. An air fitting or something like that would need pretty full thread where a hub cap retaining bolt might only need half thread.

[dneisler]

Interesting, peck tapping didn't think of that. Sounds scary though.
I may give it a try tomorrow with 750rpm and 3/8" pecks unless someone has a better suggestion.
I am new to lathes in general so I am not really sure on speeds and etc.

[adamvs]

peck tapping? You sure about that. You might be able to cobble it together using G33. but it's trailblazing. I did a job in 4130 with a 12-20 tap, that would do it all day long.
If you can reduce the % of thread from 75% to 50ish. You can drill a bigger tapping hole that way. Also get a good YG1 spiral tap with the 'slick' coating .. they really work well - the chip just curls right out of the hole.

[LeeWay]

Not actually peck tapping, but tapping progressively deeper each time. I don't know if CAM will actually call that out. Just program repeated stabs at the hole. Essentially peck tapping. I haven't tried any tapping on the lathe yet, but I do this on the mill when I have to tap deeper holes in steel and it works fine. Threads are fine. Of course the servo spindle there has better awareness of where it is, but the lathe should be able to do it like that too I would think.

[dneisler]

Pathpilot has peck tapping as a option I will give it a try.
Hole is 27/64 and cannot change.
1.375 deep and can change.
Threads needed for 1.02 inches.
These are the taps I am trying to use.





Sent from my iPhone using Tapatalk

[LeeWay]

Those are good taps. Let us know how it goes.
Lee

[LeeWay]

Were you able to get this working correctly. I recently designed some production parts that needed tapping. Just 10/24 in 6061 aluminum, but it went as expected. No problems at all.
I like to program the speed in multiples of the thread pitch. For 1/2- 13, I might use 520 RPM or even more like 1040 RPM. That just makes better sense to me. It may not actually matter in reality.

[dneisler]

Works fine in a collet holder. I was seeing thread quality issues and switched too a floating holder from maritool. Didn't make any difference really. I then bought a axial indicated where I could center taps and drills better and my issue seemed to have gone away. I am tapping 1/2-13 any from 500-700 rpm successfully. Any less and it will stall the spindle.


Sent from my iPhone using Tapatalk

[LeeWay]

Good to hear about the tapping. I think it is much easier to use smaller taps like this than single point threading tools. Above 1/2" would be where they really come into play.
I was using just a bar in a 3/4" collet to zero with, but that still basically uses the eyeball method. Now will now be using an electronic edge finder. It will work on our mill to find X and Y zero as well as X on the lathe.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[dneisler]

I've considered that as well but I am using square stock it really doesn't work.


Sent from my iPhone using Tapatalk

[LeeWay]

Right. Won't work with that the same way. You would have to use a different collet. I am gearing up to start turning one size hex bar to make some special shoulder bolts, so will still need to swap collets.
The good thing about my lathe and I am not sure why it is so much better than others is that the X homes within like .001 and .002 inches each day. The stepper motor must bump back that amount each day. It took several months to see a noticeable offset from center in X before I reset the X zero. Z doesn't matter because we face each part.