Code reference
G17, G18, G19: Plane Selection in G-Code Explained
G17 selects the XY plane, G18 the XZ plane, and G19 the YZ plane. Here is what plane selection controls, why arcs depend on it, and when to switch.
Lawrence Arya··4 min
Code reference
G20 vs G21: Inch vs Metric in G-Code, Explained
G20 tells the control to read the program in inches and G21 in millimeters. Here is the difference, why the wrong one is dangerous, and how to keep them straight.
Lawrence Arya··4 min
Code reference
G28 Return to Home Position in G-Code, Explained
G28 sends the machine back to its reference (home) position, through an intermediate point you specify. Here is how it works and how to use it safely.
Lawrence Arya··4 min
Code reference
G41 vs G42: Cutter Compensation Left vs Right
G41 offsets the cutter to the left of the path and G42 to the right. Here is how cutter compensation works, the D register, and how to engage it without a crash.
Lawrence Arya··4 min
Code reference
G43 Tool Length Offset in G-Code, Explained
G43 applies a tool's stored length so its tip reaches the programmed Z, no matter how long the tool is. Here is how G43, the H register, and G49 work.
Lawrence Arya··5 min
Guides
G50 Max Spindle Speed on a Lathe (and the Crash)
On a lathe, G50 S sets the maximum spindle RPM. Leave it out with constant surface speed and the spindle can run away near the center. Here is why and the fix.
Lawrence Arya··4 min
Code reference
G54 Work Offsets Explained for CNC Beginners
G54 tells the machine where your part zero is. Here is what a work offset stores, how G54 to G59 differ, and how to set one without cutting in the wrong place.
Lawrence Arya··4 min
Code reference
G81 vs G83: Drilling Canned Cycles Explained
G81 is a simple drill cycle and G83 is a peck drill cycle for deep holes. Here is how canned cycles work, their R, Z, and Q words, and when to use each.
Lawrence Arya··5 min
Code reference
GRBL Alarm 1 vs Error 1: What Each Means and the Fix
GRBL has two different number-1 messages: error:1 is a malformed G-code word, ALARM:1 is a tripped hard limit with position lost. Here is how to fix each.
Lawrence Arya··5 min
Code reference
Heidenhain Conversational vs Fanuc G-Code Compared
Heidenhain Klartext is readable dialogue code like L X+50 FMAX; Fanuc speaks word-address blocks. Here is how the two map and which to learn when.
Lawrence Arya··4 min
Practice
Homag woodWOP to G-Code: What Converts and What Doesn't
woodWOP programs are parametric MPR files, not G-code, and no clean converter bridges them. Here is how the formats relate and the routes that actually work.
Lawrence Arya··4 min
Guides
How to Calculate Feed Rate for G01 (Beginner Guide)
The F value on a G01 line is feed rate, and you calculate it from spindle speed, feed per tooth, and the number of flutes. Here is the formula with a worked example.
Lawrence Arya··5 min