Need Help!- Rigid Tap Questions

[CNC-ERIC]

• 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? Is lyndex Positive drive holder a rigid tap 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? and the rpm on Aluminum 6061 T6 and SS 306?
• 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? do you use peck tap for rolling tapping?
• What brand tap do you suggest?
• How to deal with 1/8-27NPT hole on Aluminum ? what type tap do you use? rpm? peck or not?

Thanks very much
Eric

[cam1]

Wow,alot of questions
-the tap choice is based in the material you are cutting, spiral fluted taps eject the swarf out of the hole, roll for taps (for aluminium) displace the material.
-rigid tapping is rigid, a collet holder will do.
-refer to the tap manufacturer for speeds, also depends on the machine tool you are using it on (machine runs spindle/axis in closed loop, and can fault on following error at lower rpm's)
-feedrate for rigid tapping must be exactly synchronized to spindle rpm (pitch X rpm=feedrate in IPM)
-don't use std pilot drill sizes for roll forming thread in AL, refer to tap manufacturer for suggested sizes.

that's the extent of my experience

regards

[Geof]

Originally Posted by CNC-ERIC •1 What type tap is suitable to CNC Rigid Tap on CNC? Rolling form tap, spiral fluted tap? •2 What type holder is used for rigid tap? Is lyndex Positive drive holder a rigid tap holder?, normal collet chuck holder? Which is better? •3 For small thread hole, such as,1-72 7 mm deep, 2-56 12 mm deep, what tap is the best choice? and the rpm on Aluminum 6061 T6 and SS 306? •4 I noticed that there is a little bit material pushed out when forming tap a through hole, how to deal with this? •5 When working on Aluminum and Stainless 306, what type tap do you use? And how is about the feedrate? •6 When rolling tap, do you use lub. Oil ? How do you handle the coolant in the drilled hole? do you use peck tap for rolling tapping? •7 What brand tap do you suggest? •8 How to deal with 1/8-27NPT hole on Aluminum ? what type tap do you use? rpm? peck or not? Thanks very much Eric

I will try to answer some of your questions (I put in numbers to help me keep things straight:

1, When you are using a cutting tap use spiral flute on a blind hole and spiral point on a through hole. I cannot comment on form taps because I do not use them. The reason that I do not use them is that years ago with manual machines I developed a prejudice against them. I let this influence me when I switched to CNC so now I have hundreds of programs that use cutting taps. Maybe it would be a good idea to switch so if someone will volunteer to edit all my programs I will switch. The moral of this story of don't let prejudice guide your choicesd.

2, I just use regular collet holders and all my machines have Rigid tapping.

3, I cannot comment on stainless; for aluminum I would use 1000 rpm and I have to admit the only reason I use 1000 rpm is that it simplifies the feed calculation.

4, This I do know about form taps; this push the material to one side. Put a slightly larger chamfer to allow for this. Whoops, I re-read the question...you are talking about the ridge at the bottom. I guess you will have to do a manual countersinking/deburring operation. Buy a little drill press so your operators can do this by the machine while the cycle is running.

5, Normal spiral flute or spiral point as mentioned above for aluminum, Stainless I do not tap.

6, Cannot answer.

7, We use Yamawa. I think that is the brand. Why? Because that is what the tool supplier about 1 km down the road stocks.

8, 1/8 NPT? Tap drill size 11/32. I would not peck tap. NPT taps are very strong for the thread size so you can probably drive them in full depth without any worry. My experience with NPT taps is that if you screw up you will either strip the thread or stall the machine, but you will not break the tap.