G 76 & can not

[hien100881]

Hi every body !
I from Viet Nam , I have the CNC Lathe Model OTB but I can not run G 76 , If you can please help me .

[positiverake]

Whats the problem? how are you writing it?

[hien100881]

Iam run the G76 for M20 x 1.5 L = 50
T101
S800M3
G0 X1. Z5.
G76 P011060 Q20 R20 ( OR Q200 R200 )
G76 X-1.9 Z-50. R0 P960 Q20 ( OR 200 ) F1.5
G0 Z30.
My machine run but cut 1 path to x-1.9 & if set G76 P021060 or P031060 is cut 2 or 3 path to X-1.9 too. Para No 726 = 200000 can not set
thank you

[positiverake]

Are you running in metric? looks like part of you program is, looks like your starting at X plus and going to X minus, this would cause it to do some strange stuff, any way this is for a M20 x 1.5 6g external thread in metric with a major diameter of 19.85 mm. with a thread relief.

X22.4Z3.
G76P010060Q254R254
G76X18.137Z-50.P8565Q2540F1.5

If you need it in inch, let me know, you can e-mail me pedub@netzero.net
hope this helps, let me know

[mtlmnchr]

Some of these controls allow for 2 different type G76 progs a single line and a double line. There is a setting for this. if you can't find the setting, try changing the program to a single line

G76 X-1.9 Z-50. I0 K960 D20 A60 F1.5

[hien100881]

Hi
Sorry , haven't the D key

[jackson]

Try using a decimal with your R in the first line of your G76
G0 X1. Z5.
G76 P011060 Q20 R.020 ( OR Q200 R200 )
G76 X-1.9 Z-50. R0 P960 Q20 ( OR 200 ) F1.5
G0 Z30.

[jackson]

i dont use metric so you will have to convert

[tobyaxis]

Originally Posted by jackson i dont use metric so you will have to convert

MM to Inch

.03937008 * MM = inch
25.4 * Inch = MM

[Hursty]

How many passes does this take (about 24? instead of 9).
I have the Depth as 0.974mm and the Ist pass of 0.35mm for the G76 cycle, this gives 8 passes. The depth of 0.35mm would of course be too large and the tool would probably break; I therefore precede the G76 cycle with the single pass G78 cycle with a depth of 0.2mm or if your control does not have the G78 simple programme this pass with G33/G32. In this way you will reduce the total number of passes and increase production.

[jackson]

Originally Posted by Hursty How many passes does this take (about 24? instead of 9). I have the Depth as 0.974mm and the Ist pass of 0.35mm for the G76 cycle, this gives 8 passes. The depth of 0.35mm would of course be too large and the tool would probably break; I therefore precede the G76 cycle with the single pass G78 cycle with a depth of 0.2mm or if your control does not have the G78 simple programme this pass with G33/G32. In this way you will reduce the total number of passes and increase production.

well on a G76 Q controlles your depths and you have 2 Q ajust them for your amount of passes

[Hursty]

Sure you can adjust Q or D on some controlls to get the number of passes. The formula is something like; number of passes = (depth/fist pass)squared. My point was that the value you get for the first pass can result in tool breakage. The single pre cycle will avoid this.