g76 thread cycle

[warcnc]

What would the G76 lines look like for a 2-1/2"-8UN thread External and internal? Anybody looking for a programming job a motorsports environment?

[HuFlungDung]

What kind of controller? There are a couple of different formats in common usage, known as 'one line' or 'two line' formats. The exact variable syntax can also vary slightly in address (letter) name, and decimal or non-decimal formatting of some of the numbers in the command line.

[warcnc]

Originally Posted by HuFlungDung What kind of controller? There are a couple of different formats in common usage, known as 'one line' or 'two line' formats. The exact variable syntax can also vary slightly in address (letter) name, and decimal or non-decimal formatting of some of the numbers in the command line.

The typical lines would read

G97S700M3
G0X2.7Z.1M8
G76P010060
G76X....Z-.....P...Q...F.125

I'm just not sure what the best numbers for the min diameters are for external and internal threads. I want to make sure and get it right because I don't have a gage. The good thing is I'm making the nuts that go on the hubs.

[MarkT]

On Fanuc controls, the previous post is correct for 0t, 16t and 18t style controls.
For 10t,11t and15t a one line multiple repetive cycle variant is used;
X= minor diameter
Z=end point of chaseI
I = taper over length of thread
K=single depth of thread
D=depth of first pass
A=angle of thread
P=infeed type

G97S700M03;
G0 X ( rapid point in X larger than major diameter) Z (rapid in Z)M08 (coolant on);
G76 X (minor diameter) Z (end point of chase) I (taper if needed) K (height of thread)
D (depth of 1st pass) A (angle of thrd) P (infeed method)

You can also use the standard thread cutting canned cycle G92, you rapid to your start point as above, then in the next line state;

G92 X (depth of first pass) Z (end of chase) F (feed rate = pitch)
X (depth of 2nd pass)
X (depth of 3rd pass)
.......................repeat until minor diameter achieved

Advantage of this strategy is you have complete control over your pass depths. Disadvantage is it is a little more code to have to deal with.

Hope this helps.

MarkT.

[lostpinky]

I don't know if this thread is still active but what are the other parameters here?..Q,F...this was written by a previous employee and should cut a 3/4 NPT but the tool does not follow the same path each pass. This is for a Haas tl2

G76 X0.9601 Z-0.7935 I-0.031 K0.0541 D0.015 P1 A60 Q29000 F0.0714

[dcoupar]

Originally Posted by lostpinky I don't know if this thread is still active but what are the other parameters here?..Q,F...this was written by a previous employee and should cut a 3/4 NPT but the tool does not follow the same path each pass. This is for a Haas tl2 G76 X0.9601 Z-0.7935 I-0.031 K0.0541 D0.015 P1 A60 Q29000 F0.0714

It's a 5-1/2 year old post... I'm guessing he's solved the problem. The one thing I don't like about this forum is that half the time, there's no feedback from the original poster that the problem is solved, and which suggestion/advice solved it.

Q is the thread start angle, and F is the feed per revolution (in this case, 14 pitch, or 1/14)

[g-codeguy]

Originally Posted by dcoupar The one thing I don't like about this forum is that half the time, there's no feedback from the original poster that the problem is solved, and which suggestion/advice solved it.

x2

Bugs me too.