Thread milling with single or multiple inserts?

[magneto259]

Is there a difference in programming using a single insert versus a multiple insert cutter? Thanks in advance!

[psychomill]

No, not really. The speed/feed is still based upon the same parameters (cutting diameter, thread pitch, material, etc). The benefit is the improved finish quality, potentially faster feeds and possibly longer tool life.

[magneto259]

Thanks for the reply. I wasn't sure if it would matter or not. Does the type of cutter make a big difference in the program? Such as a insert with multiple teeth to cut with versus a single edge cutter. I used the Vardex TM generator to make some code to give me an idea on what it should look like. But depending on wether you select continuous thread or axial it looks alot different. It depended on which style of cutter, depth and diameter wether you could select either option or not. I would prefer one continuous cut unless there is a reason not to do that. Any comments are appreciated. Thanks in advance!!!!

[psychomill]

Yes it makes a difference... but mainly for the initial depth at start and the number of turns you make before you exist. Long edge inserts (multiple teeth) allows you to start deeper in the hole (for instance) and maybe only have to make one revolution to complete a thread and exit.

Single edge (AKA single point) types means you literally have to match the number of programmed revolutions as according to the depth of thread you want. For example:

1/4-20 x .300 deep
20TPI = .05 pitch

So, in theory, to achieve this deep and full threads, you'd have to make 6 revolutions with a single point (at the bare minimum - just using easy numbers here...). With an insert with multiple teeth, you only have to make 1 revolution since the insert is at least that long.

I don't use the Vardex TM generator so I'd have to see it to get what's going on. But I think what I'm mentioning above is the differerence in the software output....

[newguy81]

Magneto, We switched from single insert threadmills when Vardex came out with the new design. Man it cut our cycle time down big time. I also use a big one made by Tool-Flo in Houston for a tapered oil country thread. 5-Flute 1000SFM @ .005 per tooth. Sounds like a buzz saw in there. Great tool life, beautiful finish, can't hardly believe it. On an old Mazak H-15B too!

[magneto259]

Thanks for the replys. Here is the code im talking about this is for a 1.25x11.5 npt thread that is 2" deep. It is climb milling in cast aluminum and its using a axial divide path with a single insert cutter that is about 1" long.

%
O10(TMINRH CLIMB INCH CYCLES =2)
(Tool cutting diameter = 1.378 inch - Mazatrol Controller. Use the ISO routine on your machine.)
(Taper=1/32.0 dAlfa=22.5 Second Loop Teeth=8)
G94
G90 G00 G57 X0 Y0
G43 H10 Z2. M3 S554
G91 X0 Y0 Z-2.8021
G91 G01 G41 D60 X0.1315 Y-0.7892 F0.53
G91 G03 X0.7892 Y0.7892 Z0.0195 I0 J0.7892 F0.53
G91 G03 X-0.2694 Y0.6513 Z0.0109 I-0.9209 J0.0004 F1.77
G91 G03 X-0.6513 Y0.2701 Z0.0108 I-0.6517 J-0.6511
G91 G03 X-0.6518 Y-0.2696 Z0.0109 I-0.0004 J-0.9216
G91 G03 X-0.2703 Y-0.6518 Z0.0109 I0.6516 J-0.6522
G91 G03 X0.2698 Y-0.6523 Z0.0108 I0.9223 J-0.0004
G91 G03 X0.6523 Y-0.2705 Z0.0109 I0.6527 J0.6521
G91 G03 X0.6527 Y0.2701 Z0.0109 I0.0004 J0.9229
G91 G03 X0.2707 Y0.6527 Z0.0108 I-0.6526 J0.6531
G91 G03 X-0.7892 Y0.7892 Z0.0195 I-0.7892 J0
G00 G40 X-0.1342 Y-0.7892 Z0
G91 X0 Y0 Z0.5702
G91 G01 G41 D60 X0.1532 Y-0.7892 F0.53
G91 G03 X0.7893 Y0.7892 Z0.0190 I0 J0.7892 F0.53
G91 G03 X-0.2758 Y0.6667 Z0.0109 I-0.9426 J0.0004 F1.77
G91 G03 X-0.6667 Y0.2764 Z0.0109 I-0.6671 J-0.6665
G91 G03 X-0.6671 Y-0.2760 Z0.0109 I-0.0004 J-0.9433
G91 G03 X-0.2767 Y-0.6671 Z0.0108 I0.6670 J-0.6676
G91 G03 X0.2762 Y-0.6676 Z0.0109 I0.9440 J-0.0004
G91 G03 X0.6676 Y-0.2769 Z0.0109 I0.6680 J0.6675
G91 G03 X0.6681 Y0.2764 Z0.0108 I0.0004 J0.9447
G91 G03 X0.2771 Y0.6681 Z0.0109 I-0.6679 J0.6685
G91 G03 X-0.7892 Y0.7892 Z0.0191 I-0.7892 J0
G00 G40 X-0.1560 Y-0.7892 Z0
G90 G00 Z8.0000
G49 M5
M99
%

Is there a code in G or mazatrol that will let me select a continuous or axial path?

[newguy81]

Just out of curiousity, why is the thread so long? API 5B calls for the thread to be 1.0625 + or - one thread.

[magneto259]

I just made it that long. We never run any that long. I did it for a example.

I've been doing some homework and i understand the code you gave me more
the I code is the increment along the x axis from the start point of the arc to the arc center.
The J code is the increment along the Y axis from the start point of the arc to the arc center.

[magneto259]

Here is a snippet out of the programming book I got from mazak. Does this look kosher.

http://img359.imageshack.us/my.php?i...doc4152kd6.png

http://img87.imageshack.us/my.php?image=sdoc4151er0.png

Thanks in advance!