Does anyone know, what is the biggest N.C tap that I could safely use
for rigid tapping (maybe with a floating tap holder), without
jeopardising gearing and such, of the head, due to tapping torque?

i

Ignoramus6489 wrote:

Does anyone know, what is the biggest N.C tap that I could safely use
for rigid tapping (maybe with a floating tap holder), without
jeopardising gearing and such, of the head, due to tapping torque?

i

With the 2-3 HP motor, variable pitch drive and back gear, I'd expect
you have available torque for tapping far larger than anything you're
likely to want to do. The Interact may not have been designed for rigid
tapping, but it was expected to be used with tapping heads, and I don't
think the torque requirements are any different for those.

On 2010-09-07, Pete C. wrote:

Ignoramus6489 wrote:

Does anyone know, what is the biggest N.C tap that I could safely use
for rigid tapping (maybe with a floating tap holder), without
jeopardising gearing and such, of the head, due to tapping torque?

i

With the 2-3 HP motor, variable pitch drive and back gear, I'd expect
you have available torque for tapping far larger than anything you're
likely to want to do. The Interact may not have been designed for rigid
tapping, but it was expected to be used with tapping heads, and I don't
think the torque requirements are any different for those.

Say, would 3/4" NC be an issue? This is the biggest thread I had to
tap to date.

i

On 2010-09-07, Ignoramus6489 wrote:
Does anyone know, what is the biggest N.C tap that I could safely use
for rigid tapping (maybe with a floating tap holder), without
jeopardising gearing and such, of the head, due to tapping torque?

I would suspect that in back gear you could handle 1/2" threads.
Anything larger, I would look into thread milling anyway -- less stress
on the machine, and more thread pitches possible with a single cut
thread mill. Of course, with a multi-cut one, you could mill the thread
in a single pass around the hole, but the mill would be good only for a
single specific pitch.

Good luck,
DoN.

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On Mon, 06 Sep 2010 20:21:18 -0500, Ignoramus6489
wrote:

Does anyone know, what is the biggest N.C tap that I could safely use
for rigid tapping (maybe with a floating tap holder), without
jeopardising gearing and such, of the head, due to tapping torque?

i

Ive tapped 1 1/4-8 on the Gorton with no issues in low gear. Just
chugged right along.

One of these days Ill take out a big tap and see how big I can go.

Btw..the Gorton spindle is 3hp.

Gunner


I am the Sword of my Family
and the Shield of my Nation.
If sent, I will crush everything you have built,
burn everything you love,
and kill every one of you.
(Hebrew quote)

Ive tapped 1 1/4-8 on the Gorton with no issues in low gear. Just
chugged right along.

One of these days Ill take out a big tap and see how big I can go.

Btw..the Gorton spindle is 3hp.

For me, the weak link is holding the tap. I just bought another 1" NPT
on ebay. The last one spun in the TG100 collet holder with bad
results. I do all tapping in back gear on my excello knee mill.

karl