G Code 101: Circles and Arcs

[@jeffreycole9834]

This is one of the better descriptions for I and J in the G-Code that I have seen or read. It is not complicated, but how to describe the I and J apparently can be difficult for some to describe. I can actually now see two ways to indicate I and J, and for more complicated milling, I can now throw in the K values for milling. Thanks for the description that we can understand.

[@90FF1]

Total noob here. This video topped all the words I've read on the I and J thing. Thanks

[@00kalamity10]

This video made the topic so easy to understand. I've been using g-code on and off for uni for the past 2 years. Have always struggled to understand how to get circles as you want them. You guys just helped me to ace my exam. Thank you!

[@Bobscnc]

Glad we could help!

[@KechlimparisAthanasios]

Good work guys!!Very nice explanation of the G2, G3 functionality

[@hambaallah5586]

Wow... clearer than my CNC lecturer.... subbed

[@xpeace77]

A superb video - getting to the point in lightning speed. Thank you very much.

[@urquiza1487]

You can also use an r value with a g2 or g3 command to achieve an arc

[@tora5205]

Thankyou! Very clear breakdown, appreciate it

[@AmerikkkaGuitars]

Awesome explanation. Doing fret slots for multiscale guitar. Was confused about starting and end points, Also can generate curve with radius command. Will test but I think I'm heading in right direction. Also you can use camotics to import your gcode and will give a visual realtime representation of toolpaths and it's free.

[@connerstephen6438]

Thanks for making this!

[@klawyjanjan2596]

sooooo gooood i got it! thank you guys

[@matthewchapman2494]

Great video! Thank You! I learned something.

[@28colecj]

Great video!

What about a spline? What way should we follow?

[@charleslyons6203]

You made it easy to understand thanks

[@ProfessorVector]

Very nice just knowing X Y is the end point helped so much I see people cut circles in two steps 180 degrees each is this necessary or can a 360 cut be done with one G2/G3 ? This used to be so confusing because people want to start in the center of the circle and you also have to account for the bit size and subtract that out too. I have yet to see a formula using Xc Yc for center and Xbr Ybr (bit radius) ! Yes I'm a software engineer!

[@Bobscnc]

Some gcode senders will do the entire circle if the end point is the start point. Grbl will only do 1/2, then you can do the other half. Yes there is a bit of math for the bit diameter.

[@kevincrum6259]

is there such a way to do an arc with all three axis? or at the least arching on a plane say YZ while moving X?

[@Bobscnc]

You can add a Z component as well. The principle is the same, Just at the z and the k. The k is the distance to the center of the arc in the z direction. (XYZ) (ijk)

[@celebrity_rooster7488]

Thanks for the video guys. Where can I do a circular motion in the Z axis?

[@Bobscnc]

Just add the Z and the K (XYZ, IJK)

[@hussainbhavnagarwala2596]

How would you make a full circle, I tried using the same start point as end point but Nc viewer gives a weird output

[@oathz958]

You need to use the I to make a circle only

[@stemoore5842]

On my machine I.. J.. is expressed as absolute by default. Is there a way to change this with code? I have tried G91.1 and adding D before the IJ but neither work. It has an ECS1801 control.

[@bobwood4193]

What CNC model do you have?

[@stemoore5842]

@@bobwood4193 ECS 1801

[@vasimansari1919]

Very good

[@donsahgodfred9941]

Thanks

[@RafalGajdzik]

Last LINE SHOULD NO BE G2 X9 Y3 I3 J-3 ? (you missed "Y" )

[@Bobscnc]

Yes I did...good catch!

[@official_richielau]

This is great. Is there a way to form an arc that has a different that has a different x-radius from its y-radius like an ellipse?

[@Bobscnc]

Not with a simple gcode. You would need to plot these with small segments. This work would e better suited for CAM software.

[@official_richielau]

@@Bobscnc Your arc example draws half a circle. Is it possible to draw a quarter of that circle?

[@Bobscnc]

@@official_richielau sure, just make the XY the values for the end point.

[@roberthuerta449]

most helpful video, clear and simple, no pussyfooting

[@adilhassan7817]

I’m trying to curve a diagonal line to connect my initials, how would I go about doing that? Like how would I find the center point? I’m new to this G and M code. I want to connect the bottom corner of my M to the top corner of my H. My initials are AMH.

[@Bobscnc]

It might be easier to use CAD?CAM software to do this. Search for font to gcode.

[@isaacadude6781]

you made it easier

[@TheGabusan]

I wish u could use polar coordinates

[@baonguyen-fy3ju]

Thank you

[@talgtalga3767]

Great video... i have questiin about gcode in mach3 sorry this not topic here.. am sure you know more about it) your help needs please..i have wrote down gcode by myself on notepad txt format am using x axis as clamping system linear movment in mini injection machine ...i put some codes on it and downloaded in mach3 some x axis movments and i want to use some codes as loop can repeated hole cycle till i turn off reseted button...some guys use m97, m47 but in my case no luck)) any help please??? for example in my case...g90 g1 x50 f 350 G4 P10 X0 x-10 X0 x-11 X0 (these above cycle needs to repeated... any codes as loop???)) Hope some can also help this if knows .. i really appreciated

[@bobwood4193]

LinuxCNC has a good reference for sub routines. Grbl firmware will not handle sub routines.

[@talgtalga3767]

@@bobwood4193 am using mach3 but i dont how to run my codes as loop

[@bobwood4193]

@@talgtalga3767 Please take a look at the LinuxCNC pages or search for gcode sub routines.

[@eduphymath6581]

Tnx