Simple GCode Reference / Commands?

[WarrenW]

Hi,

I am looking for a web site that shows the gcode commands for all of the basic actions. I just need to write gcode to do the following:

- Go to the starting X/Y position
- Set the plunge rate
- Set the feed rate
- Move the Z to a certain depth
- Then move at X/Y points (set of lines shaping an object)

Thats all I need to do. Do I have to specify the units (inches/mm) in the gcode?

Thanks,

Warren

[wms]

http://www.linuxcnc.org/handbook/gcode/g-code.html

[ger21]

- Go to the starting X/Y position

G0 Xx.xx Yx.xx (rapid move)

- Set the plunge rate

Fx.xx

- Move the Z to a certain depth

G1 Z-x.xx

- Set the feed rate

Fx.xx

- Then move at X/Y points (set of lines shaping an object)

G1 Xx.xx Yx.xx (straight move)

or

G2 Xx.xx Yx.xx Ix.xx Jx.xx (clockwise arc)

or

G3 Xx.x Yx.xx Ix.xx Jx.xx (ccw arc)

x.xx represents a coordinate. Notice that I changed the order. The plunge rate IS the feedrate, during the plunging move. Just set the feedrate for the current move prior to making it, or on the same line as the move.

[stupidog]

Try this link, it's pretty handy - http://www.cncezpro.com/gcodes.cfm.

[JamesJmcGEE]

Is there a g-code you can enter at the first part of the file to set the overall feedrate limt? I'm using mach 3 and have no spindle monitor/control but dont want to feed no more than 6.0 for the whole project. Im currently typing "g1 (x/y/z)?.? f6.0" on every line and that is getting old quick at my typing rate of 6 words a minute

[g-codeguy]

Feedrate is modal on most machines. You should only need to type it in once. Just cut 30 seconds per line off your typing.

[Al_The_Man]

Do I have to specify the units (inches/mm) in the gcode?

Thanks,

Warren

G20 is Inch input, G21 is Metric, some systems use G70/G71.
Al.

[davide.castro]

Hello,
I'm looking a parameter or G code (fanuc OM c )to do that: if the program a have 3 points that made a line and if I start the program the machine almost stop in the points and i dont wont that.
Davide.

[JamesJmcGEE]

Feedrate is modal on most machines. You should only need to type it in once. Just cut 30 seconds per line off your typing.

ok.... I'm not very up on that could you explain a little more?
Im thinking that means leave my first line and then the rest I dont need to write it anymore as in:
G1 z-.05 f6.0 (slow)
g1 x 2.5 (slow)
g1 y 2.5 (slow)
g0 z.25 (then rapid move)
g0 x0. (rapid move)
g0 y0. (rapid move)
g1 z-.075 (slow again)
g1 x 2.5 (slow again)
g1 y 2.5 (slow again)

Is that correct?
Thanks!
J

[g-codeguy]

James: Yes & No.

This is all that is needed.

G1 Z-.05 F6. (slow)
X 2.5 (slow)
Y 2.5 (slow)
G0 Z.25 (then rapid move)
X0Y0 (rapid move)
G1 Z-.075 (slow again)
X 2.5 (slow again)
Y 2.5 (slow again)

Yes. modal means the F6. stays in affect until you use an F with a different feedrate. In your example the one F6. is all that is necessary.

No, model means a G-code stays in affect until another complimentary G-code is used. G0, G1, G2, & G3 cancel each other out. If you made a 360 degree circle programming it in quadrants using G2, then all that would be necessary is the first G2. The other 3 blocks needn't have the G2. You can use it, but it isn't necessary. You would need a G1 or G0 to cancel the G2 after completing the circle. Programming straight lines only requires the first G1.

The X0 Y0 needn't be on separate blocks unless they need to be programmed that way to clear a clamp, or if Z0 wasn't the face of the part, and a section was high enough that Z.25 wouldn't clear it when moving to X0Y0.

Same thing for metric versus inches. This should be set by a parameter in the control. You don't need to program another unless changing from one to the other.

Same thing for IPM versus IPR. Parameter in machine controls the one used on start-up. Only need another G-code to change it if going from one to the other.

Same thing for G96/G97. One cancels the other. You can change from G97S1000M3 to a spindle speed of 500 in the same operation by simply programming S500. The G97M3 aren't needed. They are modal. Works the same way for G96.

Not to say that this is how it works on every machine. I am a long ways from having run every machine with every type of control. There could be some flaky ones that require a G1 or G0 on every block, etc. I've never seen one. Doesn't mean they don't exist.

[g-codeguy]

Hello,
I'm looking a parameter or G code (fanuc OM c )to do that: if the program a have 3 points that made a line and if I start the program the machine almost stop in the points and i dont wont that.
Davide.

Sorry, but I don't understand what you are wanting to know. Would you explain further? Be glad to help if I can.

[JamesJmcGEE]

James: Yes & No.

This is all that is needed.

G1 Z-.05 F6. (slow)
X 2.5 (slow)
Y 2.5 (slow)
G0 Z.25 (then rapid move)
X0Y0 (rapid move)
G1 Z-.075 (slow again)
X 2.5 (slow again)
Y 2.5 (slow again)

Yes. modal means the F6. stays in affect until you use an F with a different feedrate. In your example the one F6. is all that is necessary.

No, model means a G-code stays in affect until another complimentary G-code is used. G0, G1, G2, & G3 cancel each other out. If you made a 360 degree circle programming it in quadrants using G2, then all that would be necessary is the first G2. The other 3 blocks needn't have the G2. You can use it, but it isn't necessary. You would need a G1 or G0 to cancel the G2 after completing the circle. Programming straight lines only requires the first G1.

The X0 Y0 needn't be on separate blocks unless they need to be programmed that way to clear a clamp, or if Z0 wasn't the face of the part, and a section was high enough that Z.25 wouldn't clear it when moving to X0Y0.

Same thing for metric versus inches. This should be set by a parameter in the control. You don't need to program another unless changing from one to the other.

Same thing for IPM versus IPR. Parameter in machine controls the one used on start-up. Only need another G-code to change it if going from one to the other.

Same thing for G96/G97. One cancels the other. You can change from G97S1000M3 to a spindle speed of 500 in the same operation by simply programming S500. The G97M3 aren't needed. They are modal. Works the same way for G96.

Not to say that this is how it works on every machine. I am a long ways from having run every machine with every type of control. There could be some flaky ones that require a G1 or G0 on every block, etc. I've never seen one. Doesn't mean they don't exist.

Thanks a million! You saved me a whole lot of time and trouble!