Rigid Tap Questions

[CNC-ERIC]

Hi,Guys,

 

I have no experience on rigid tap, my questions may be stupide, pls don't laugh, , help me, thank in advance.

 

• What type tap is suitable to CNC Rigid Tap on CNC? Rolling form tap, spiral fluted tap?

• What type holder is used for rigid tap? Positive drive holder, normal collet chuck holder? Which is better?

• For small thread hole, such as,1-72 7 mm deep, 2-56 12 mm deep, what tap is the best choice?

• I noticed that there is a little bit material pushed out when forming tap a through hole, how to deal with this?

• When working on Aluminum and Stainless 306, what type tap do you use? And how is about the feedrate?

• When rolling tap, do you use lub. Oil ? How do you handle the coolant in the drilled hole?

• What brand tap do you suggest?

• how to do 1/8 NPT tap on Aluminum, peck tap or not? what type tap do you suggest to use?

 

Eric

[Guest]

quote:

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• What type tap is suitable to CNC Rigid Tap on CNC? Rolling form tap, spiral fluted tap?

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Both are fine

 

quote:

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• What type holder is used for rigid tap? Positive drive holder, normal collet chuck holder? Which is better?

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The endmill holders should not be used, the shank size on taps does not lend itself to fitting snugly. I have used collet holder but I prefer to use rigid tapping heads

 

quote:

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• For small thread hole, such as,1-72 7 mm deep, 2-56 12 mm deep, what tap is the best choice?

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Thru hole I would likely use a cutting tap, blind hole I will generally use a roll form tap

 

 

quote:

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• I noticed that there is a little bit material pushed out when forming tap a through hole, how to deal with this?

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as noted above if the hole is through I generally use a cutting tap, if it is blind I generally use a roll form. Using a cut tap does not produce this excess material push.

 

quote:

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• When working on Aluminum and Stainless 306, what type tap do you use? And how is about the feed rate?

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As fast as will reliably work, I generally try to keep my feed rates on taps between 8 to 20 inches. ON a 2-56 I would start at 560 RPM and a feed rate of 10 IPM, it could then be adjusted up or down as needed.

 

quote:

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• When rolling tap, do you use lub. Oil ? How do you handle the coolant in the drilled hole?

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In most cases coolant works fines. In those rare cases where it did not, I would place and M00 and add a note for the operator to use Moly-Dee at which time he could brush the tap and holes and complete the operation. note, that little channel running up the side of a roll tap is an oil groove it allows fluid in the hole to be ejected as the tap gets deeper into a blind hole.

 

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• What brand tap do you suggest?

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I have used a lot of Balax, OSG and emuge taps

 

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• how to do 1/8 NPT tap on Aluminum, peck tap or not? what type tap do you suggest to use

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Drill the tap drill hole and tap, a 1/8 NPT in general will not need to be peck tapped, it is a fairly small tap and even a HAAS should have the stones to drive it to depth. Just a regular cutting tap should be fine.

[JerryBenoit]

quote:

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• What type holder is used for rigid tap? Positive drive holder, normal collet chuck holder? Which is better?

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http://www.tapmatic.com/

 

 

Tapmatic has what they call a Synchroflex. We have found that most machines have an issue when reversing the spindle the Z axis will feed ahead or behind the lead of the tap. Especially if you are tapping a 3B pitch. You may want to look into this, if your machine has any age or if you run into pitch is going oversized on you.

[CNC-ERIC]

Hi, John,

 

I use Lyndex positive drive holder for 1-72 rolling tapping, through hole, 7mm deep, rpm 1440(feedrate 20), A9 lub. it was broken when finish 10 holes.

 

do you use positive drive? is it not "rigid" enough? I noticed that there is still a little movable space, not like in ER collet chuch that the tap was deadly holded.

 

Eric

[Guest]

quote:

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I use Lyndex positive drive holder for 1-72 rolling tapping, through hole, 7mm deep, rpm 1440(feedrate 20), A9 lub. it was broken when finish 10 holes.

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Personally, I think that is too fast for a tap that small.

 

Also, are you SURE your machine is set up for rigid tapping?

 

What kind of machine are you doing this on?

[CNC-ERIC]

Hi,John

our machine is HAAS VF-2,I am sure the machine set up for rigid tapping.

 

do you think the Lyndex Positive Drive maybe a factor?

 

I did not try to use a ER holder to hold the 1-72 rolling tap.

 

thanks

 

Eric

[Guest]

The Lyndex Holders are generally considered a good work holding option.

 

What size drill?

What material?

 

I really think the 7mm depth is going to be your biggest issue.

 

 

What moron Engineer called out that spec?

 

.072 major diameter at .107 deep that screw is as strong as it is going to get, you're going .280 deep. Crazy on a tap that size

[Programinator]

Sometimes you have to play with the hole sizes with a form tap. Try going .001 - .003 bigger with the drill size any you may get better results.

 

Also try putting a J1 in the tapping cycle and it will reverse at the same feed rate as it went in the hole at.

 

Just a couple of things to rule out what may be the problem.