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Machines => CNC Machines => Topic started by: kopcicle on Dec 19, 2024, 04:56 PM

Title: Need help with G19 G02(3) (Y,Z, J,K) +x
Post by: kopcicle on Dec 19, 2024, 04:56 PM
I'm having a great deal of trouble with what should be a simple manual gcode. This is a simple move, or should be but I can't seem to get the syntax even remotely correct.

G19 G02(3) (Y,Z, J,K)

Preamble.

Circular segment - is an area of a "cut off" circle from the rest of the circle by a secant (chord).

On the picture:
L - arc length
h - height
c - chord
R - radius
a - angle

If you know the radius and the angle, you may use the following formulas to calculate the remaining segment values:
R=52
Height=3.1360
Chord length=35.5701 1/2 Chord length=17.78505
Arc length=36.3028 1/2 Arc length=18.1514

I'm using an angle of 40 degrees because I will have to start at X0,Y0, Z52 (R) and move clockwise from Top Dead Center (for lack of a better description) to the end point of the radius.

I'm assuming I can do this in incremental as well as absolute and the syntax would be nearly the same save for G98 (absolute) G91 (incremental) modes. Still the syntax escapes me.

Using G19 , from TDC the start point, Y0 Z0, the end point would be 1/2 the chord length,  17.78505 and the height, -3.1360, while assuming (yeah, yeah , I know) the offset is 52 for the radius.

But wait, that's not all. I have an X move I need to add. That is relatively simple math that finds a common denominator  between  1/2 the arc length,  18.1514 and the X path length between 1 and 1,8. I can do triangles but.

I haven't the faintest notion of the correct syntax. I've beat my head on this long enough. It's time to humbly ask.
Title: Re: Need help with G19 G02(3) (Y,Z, J,K) +x
Post by: kopcicle on Dec 20, 2024, 12:50 PM
CW Move
G01 Y0.000 Z0.000
G19 G02 Y17.785 Z-3.136 J0.000 K-52.000

CCW Move
G01 Y0.000 Z0.000
G19 G03 Y-17.785 Z-3.136 J0.000 K-52.000

or something like that.
still not quite right
I keep messing up the machine/firmware specific headers and feeds
Title: Re: Need help with G19 G02(3) (Y,Z, J,K) +x
Post by: TerryWerm on Dec 21, 2024, 10:15 AM
I would love to help if I could, but there are not many in here that know anything substantial about G-code and what I know about it would not fill a thimble. Hopefully somebody will have the knowledge you seek.
Title: Re: Need help with G19 G02(3) (Y,Z, J,K) +x
Post by: chips and more on Dec 21, 2024, 10:39 AM
What is G-Code  :smiley_flabbergasted:
Title: Re: Need help with G19 G02(3) (Y,Z, J,K) +x
Post by: TerryWerm on Dec 21, 2024, 12:28 PM
Quote from: chips and more on Dec 21, 2024, 10:39 AMWhat is G-Code  :smiley_flabbergasted:
It is what modern machinists type in at a keyboard instead of counting turns and marks of a handwheel to achieve a part of a certain shape. It is also an amazing system in that it allows a machinist to run a program, containing the aforementioned G-code, which, if it contains an error, does an amazing job of trashing cutters, bits, chucks, and other tooling with a total and absolute lack of discretion. Additionally, it is nearly the perfect system for turning perfectly good stock into scrap in large quantities, giving recycling companies something to do.
  :tickedoff:        

No sarcastic humor here... I don't even know what that is!   
    :smiley_crocodile:
Title: Re: Need help with G19 G02(3) (Y,Z, J,K) +x
Post by: 34_40 on Dec 22, 2024, 07:15 AM
:smiley_verdrietig: :smiley_winkkiss: :smiley_tong2: you may not know what it is...  :smiley_computerfight:   but, you do it well!  :smiley_sealed:
Title: Re: Need help with G19 G02(3) (Y,Z, J,K) +x
Post by: chips and more on Dec 29, 2024, 06:25 PM
Is g-code and g-spot the same thing?
Title: Re: Need help with G19 G02(3) (Y,Z, J,K) +x
Post by: TerryWerm on Dec 29, 2024, 11:04 PM
Oh boy. I KNOW what a G-spot is, and NO, it's not the same thing!!   :smiley_crocodile:
Title: Re: Need help with G19 G02(3) (Y,Z, J,K) +x
Post by: 4GSR on Dec 31, 2024, 09:24 AM
:smiley_XD:  :smiley_crocodile: