Brandon Fowler, Author at Machinist Guides

G03 G-Code: Counterclockwise Circular Interpolation Explained

March 1, 2026 by Brandon Fowler

G03 tells your CNC machine to move in a counterclockwise circle. It follows a path along a set radius — like tracing the edge of a coin the other way — while cutting at a controlled speed.

Any time you need to cut a curved path going counterclockwise, G03 is the code you’ll use.

Key Takeaways

G03 moves the tool in a counterclockwise arc — use G02 for clockwise

Requires an endpoint (X/Y) and a radius (R) or center offsets (I/J) to define the arc
It’s a modal code — it stays on until you switch to G00, G01, or G02
G03 and G3 are the same thing — the zero is optional

For full circles, use I/J instead of R

G03 – At A Glance
Function	Counterclockwise circular interpolation
Format	G03 X__ Y__ R__ F__ or G03 X__ Y__ I__ J__ F__
Type	Modal (Group 1 – Motion)
Cancelled by	G00, G01, G02
Required params	Endpoint (X/Y) + R or I/J

What Does G03 Do?

G03 moves the cutting tool along a counterclockwise arc from one point to another. You give it an endpoint and a radius, and it figures out the curved path between the two.

illustration showing how a cnc machine moves from the start to end point when using counterclockwise circular interpolation

The machine doesn’t move in a perfect circle. It actually takes a series of very small straight steps that add up to look like a curve. This is called interpolation.

illustration showing how a CNC machine makes steps when using circular interpolation — Zoomed in circular interpolation

To use G03, you need three things:

An endpoint — where the arc stops (X and Y coordinates)

A radius — how big the arc is (R), or center offsets (I and J)
A feed rate — how fast the tool moves (F)

illustration showing the radius in a circular interpolation move

G03 is a modal code. That means it stays active until you turn it off with another movement code like G00, G01, or G02.

G03 Format

The most common format uses the R word to set the radius:

G03 X__ Y__ R__ F__

You can also use I and J instead of R. I and J define the center of the arc as an offset from your starting point:

G03 X__ Y__ I__ J__ F__

Start with the R format — it’s easier to understand. Use I and J when you need to cut a full circle or an arc larger than 180°.

G03 Code Example

O0200                          (Program number)
G90 G54 G17 G21                (Absolute mode, work offset, XY plane, metric)
G00 X25. Y0.                   (Rapid to arc start point)
M03 S1200                      (Spindle on CW at 1200 RPM)
G43 H01 Z5.                    (Tool length comp, move to clearance height)
G01 Z-5. F100.                 (Feed down to depth)
G03 X0. Y25. R25. F200.        (Counterclockwise arc: 90° cut, 25mm radius)
G00 Z50.                       (Rapid to safe height)
M05                            (Spindle off)
M30                            (End program)

The tool starts at X25, Y0. It cuts a counterclockwise arc to X0, Y25 — a 90° curve with a 25mm radius. The radius in the R word matches the distance from the start point to the center of the arc.

COMMON MISTAKE – Using G03 When You Need G02

If the arc cuts in the wrong direction, stop the machine immediately.

G02 goes clockwise, G03 goes counterclockwise — viewed from above, looking down at the XY plane.

A quick check: if your arc should curve to the left, it’s G03. If it curves to the right, it’s G02. Always verify in simulation before you run it.

G03 vs G02

G02 and G03 work the same way. The only difference is direction. G03 goes counterclockwise. G02 goes clockwise. Both are viewed from above, looking down at the XY plane.

illustration showing how a cnc machine moves from the start to end point when using clockwise circular interpolation

Which one you need depends on the shape of the part. Inside corners often use G03. Outside corners might use G02.

CAM software picks the right one for you automatically — but if you’re writing code by hand, think through the direction before you write it.

G3 vs G03 — Does the Zero Matter?

No. G3 and G03 do the exact same thing. The leading zero doesn’t change anything.

Textbooks and formal references tend to use G03 while many programmers will use G3 to save a keystroke. If your shop has a standard, follow it — otherwise use whichever you prefer.

When to Use G03

Use G03 any time you need to cut a counterclockwise arc or radius. Common situations:

Rounding an inside corner on a part
Cutting a full or partial circular profile
Blending a smooth radius between two straight cuts
Milling around a curved feature

In a real program, G03 usually comes after the tool is positioned, the length offset is applied (G43), and the tool has fed down to depth with G01.

Things to Check Before You Run G03

Units

Know whether you’re working in inches or millimeters. G20 sets inches, G21 sets millimeters.

A 25mm arc run in inches mode will move 25 inches — not what you want.

Absolute vs. Incremental Mode

How the controller interprets your coordinates depends on whether you’re in G90 (absolute) or G91 (incremental) mode.

Absolute (G90): coordinates are measured from the program zero.
Incremental (G91): coordinates are measured from the current position.

The images below show the difference between the absolute and incremental positioning modes. The numbers in parentheses are the locations given to the the machine to make the move.

graph paper example of absolute positioning with multiple points as examples

graph paper example of incremental positioning with multiple points as examples

Start and Stop Positions

Think through the full path the tool takes — not just the arc itself. Where is the tool starting? Where does it end up? Is there anything in between, like a clamp or vise jaw? It’s easy to forget about fixturing and end up crashing into it.

How to Cancel G03

There’s no specific cancel code for G03. Just switch to any other movement code:

The new code takes over on that line and G03 turns off.

Codes Used With G03

The codes below are used with the G03 code or commonly found very close to a G03 command in a CNC program:

G17/G18/G19 – Sets the cutting plane (XY, XZ, or YZ). Most mills default to G17 (XY).
M03 – Spindle on, clockwise
M08 – Flood coolant on
M09 – Coolant off
N – Program line number
R – Radius size
S – Set spindle speed
X – X axis location
Y – Y axis location

FAQS

What is the difference between G02 and G03?

G03 moves counterclockwise. G02 moves clockwise. Both use the same format — endpoint plus radius or I/J plus feed rate. The direction is the only difference.

Can I cut a full circle with G03?

Yes. Set your start and end point to the same location, then use I and J to define the center. You don’t need an X/Y endpoint when the arc starts and ends at the same spot.

When should I use I/J instead of R?

Use I/J for full circles and arcs over 180°. The R method can confuse some controls on large arcs. I/J is always explicit about where the center is.

G02 G-Code: Clockwise Circular Interpolation Explained

March 1, 2026 by Brandon Fowler

G02 tells your CNC machine to move in a clockwise circle. It follows a path along a set radius — like tracing the edge of a coin — while cutting at a controlled speed.

Any time you need to cut a curved path going clockwise, G02 is the code you’ll use.

Key Takeaways

G02 moves the tool in a clockwise arc — use G03 for counterclockwise

Requires an endpoint (X/Y) and a radius (R) or center offsets (I/J) to define the arc
It’s a modal code — it stays on until you switch to G00, G01, or G03
G02 and G2 are the same thing — the zero is optional

G02 – At A Glance
Function	Clockwise circular interpolation
Format	G02 X__ Y__ R__ F__ or G02 X__ Y__ I__ J__ F__
Type	Modal (Group 1 – Motion)
Cancelled by	G00, G01, G03
Required params	Endpoint (X/Y) + R or I/J

What Does G02 Do?

G02 moves the cutting tool along a clockwise arc from one point to another. You give it an endpoint and a radius, and it figures out the curved path between the two.

The machine doesn’t move in a perfect circle. It actually takes a series of very small straight steps that add up to look like a curve. This is called interpolation.

To use G02, you need three things:

An endpoint — where the arc stops (X and Y coordinates)

A radius — how big the arc is (R), or center offsets (I and J)
A feed rate — how fast the tool moves (F)

G02 is a modal code. That means it stays active until you turn it off with another movement code like G00, G01, or G03.machine stays in clockwise arc mode until you switch to G00, G01, or G03.

G02 Format

The most common format uses the R word to set the radius:

G02 X__ Y__ R__ F__

You can also use I and J instead of R. I and J define the center of the arc as an offset from your starting point:

G02 X__ Y__ I__ J__ F__

Start with the R format — it’s easier to understand. Use I and J when you need to cut a full circle or an arc larger than 180°.

G02 Code Example

O0100 (Program number)
G90 G54 G17 G21 (Absolute mode, work offset, XY plane, metric)
G00 X0. Y-25. (Rapid to arc start point)
M03 S1200 (Spindle on CW at 1200 RPM)
G43 H01 Z5. (Tool length comp, move to clearance height)
G01 Z-5. F100. (Feed down to depth)
G02 X25. Y0. R25. F200. (Clockwise arc: 90° cut, 25mm radius)
G00 Z50. (Rapid to safe height)
M05 (Spindle off)
M30 (End program)

The tool starts at X0, Y-25. It cuts a clockwise arc to X25, Y0 — a 90° curve with a 25mm radius. The radius in the R word matches the distance from the start point to the center of the arc.

COMMON MISTAKE – Using a Negative R Value

A negative R value tells the machine to take the long way around the arc — more than 180°. A positive R takes the short route. Mix them up and the tool goes the wrong way, or cuts into your part.

Check your arc in simulation before you run it to make sure you got it right.

G02 vs G03

G02 and G03 work the same way. The only difference is direction. G02 goes clockwise. G03 goes counterclockwise. Both are viewed from above, looking down at the XY plane.

Which one you need depends on the shape of the part. Outside corners often use G02. Inside corners might use G03. CAM software picks the right one for you automatically — but if you’re writing code by hand, think through the direction before you write it.

G2 vs G02 — Does the Zero Matter?

No. G2 and G02 do the exact same thing. The leading zero doesn’t change anything.

Textbooks and formal references tend to use G02 while many programmers will use G2 to save a keystroke. If your shop has a standard, follow it — otherwise use whichever you prefer.

When to Use G02

Use G02 any time you need to cut a clockwise arc or radius. Common situations:

Rounding an outside corner on a part
Cutting a full or partial circular profile
Blending a smooth radius between two straight cuts
Milling around a curved feature

In a real program, G02 usually comes after the tool is positioned, the length offset is applied (G43), and the tool has fed down to depth with G01.

Things to Check Before You Run G02

Units

Know whether you’re working in inches or millimeters. G20 sets inches, G21 sets millimeters.

A 25mm arc run in inches mode will move 25 inches — not what you want.

Absolute vs. Incremental Mode

How the controller interprets your coordinates depends on whether you’re in G90 (absolute) or G91 (incremental) mode.

Absolute (G90): coordinates are measured from the program zero.
Incremental (G91): coordinates are measured from the current position.

The images below show the difference between the absolute and incremental positioning modes. The numbers in parentheses are the locations given to the the machine to make the move.

Start and Stop Positions

How to Cancel G02

There’s no specific cancel code for G02. Just switch to any other movement code:

The new code takes over on that line and G02 turns off.

Codes Used With G02

You’ll rarely see G02 by itself. Here’s what usually goes with it:

G17/G18/G19 – Sets the cutting plane (XY, XZ, or YZ). Most mills default to G17 (XY).

FAQS

What is the difference between G02 and G03?

G02 moves clockwise. G03 moves counterclockwise. Both use the same format — endpoint plus radius or I/J plus feed rate. The direction is the only difference.

Can I cut a full circle with G02?

Yes. Set your start and end point to the same location, then use I and J to define the center. You don’t need an X/Y endpoint when the arc starts and ends at the same spot.

When should I use I/J instead of R?

Use I/J for full circles and arcs over 180°. The R method can confuse some controls on large arcs. I/J is always explicit about where the center is.

G01 G-Code: Linear Interpolation Explained with Examples

March 1, 2026 by Brandon Fowler

G01 is the command that tells your CNC machine to move in a straight line while actively cutting material. If G00 gets the tool where it needs to be, G01 is what actually does the machining.

Key Takeaways

G01 moves the tool in a straight line at a feed rate you control with the F command
It’s modal — once called, it stays active until you switch to G00, G02, or G03

You must have a feed rate (F) set before or on the same line as G01, or the machine will alarm out
G01 is for cutting. G00 is for positioning. Don’t mix them up.
G1 and G01 are identical — the leading zero is optional

G01 – At A Glance
Function	Straight-line movement at a controlled feed rate
Format	G01 X__ Y__ Z__
Type	Modal (Group 1)
Cancelled by	G00, G02, G03
Requires	F (feed rate) — must be set

What Does G01 Do?

G01 sets the machine’s movement mode to linear interpolation — a straight-line move from the current position to a target XYZ location.

The CNC axes move so the path is perfectly straight, not a sequence of individual axis movements.

an illustration that shows the X, Y and Z axes on a CNC machine

Speed is controlled by the F command (feed rate). You set a feed rate, call G01, give it a destination, and the machine handles the rest.

G01 is a modal command, which means it stays active until you replace it with another movement command — G00, G02, or G03. You don’t need to repeat G01 on every line.

Format for using a G01 code

The basic format is:

G01 X__ Y__ Z__ F__

You don’t need all three axes every time — include only the ones you’re moving. The F value only needs to appear once and stays in effect until you change it.

G01 X1.0 F20.0     (Move to X1.0 at 20 IPM — Y and Z don't move)
Y2.5               (Move to Y2.5 — still G01, still F20.0)
X3.0 Y4.0 Z-0.25   (Move all three axes simultaneously in a straight line)

G01 vs G1 — Is the Zero Required?

No. G01 and G1 are identical. Most CNC controls accept both.

In practice, experienced programmers often use the shorter G1 to save keystrokes. If your shop has a programming standard, follow it. If it’s your own code, use whichever format you prefer.

G01 vs G00

Both commands move the tool in a straight line. The difference is speed and intent.

G01 moves at your programmed feed rate. Use it when the tool is cutting material — the speed controls your chip load, surface finish, and tool life.

G00 moves at the machine’s maximum speed and ignores the feed rate entirely. Use it for positioning only — getting the tool to the right spot before you start cutting.

Real Program Example

O0101                           (Program number)
G90 G54                         (Absolute mode, work offset 1)
G00 X0.0 Y0.0                   (Rapid to start position)
G43 H01 Z0.5 M03 S1200          (Tool length comp, spindle on at 1200 RPM)
G01 Z-0.125 F10.0               (Feed to depth at 10 IPM — now cutting)
X4.0                            (Cut along X axis)
Y3.0                            (Cut along Y axis)
X0.0                            (Return along X)
Y0.0                            (Return along Y — square perimeter complete)
G00 Z1.0                        (Rapid clear)
M05                             (Spindle off)
M30                             (Program end)

G01 is called once and stays modal through the entire cutting section. The feed rate is set on that first line and carries through every cut that follows.

What to Watch Out For

Units — Inches vs Millimeters

Make sure your program has the right units code set. G20 is inches, G21 is millimeters. Moving 10 millimeters instead of 10 inches is a crash waiting to happen.

Absolute vs Incremental Mode

G01 works in whatever positioning mode is currently active. G90 (absolute) means all coordinates reference your work zero. G91 (incremental) means coordinates are relative to where you are right now. Know which one you’re in before writing moves.

The images below show the difference between the absolute and incremental positioning modes. The numbers in parentheses are the locations given to the the machine to make the move.

Know Your Path

G01 moves in a perfectly straight line from point A to point B. Before calling it, think about the path — not just the destination.

Clamps, vises, and fixture bolts live between start and end points. A move that looks correct on paper can still crash if something’s in the way.

COMMON MISTAKE – Forgetting Your Feed Rate

Calling G01 without a feed rate set on the same line or earlier in the program. On most controls this triggers an alarm. Always verify F is set before your first G01 cut.

How to Cancel G01

G01 doesn’t have a dedicated cancel command — you switch to another Group 1 movement code:

Using any of these codes will turn G01 off and switch to the new movement mode.

Other Relevant codes

The codes below are used with the G01 code or commonly found very close to a G01 command in a CNC program:

FAQS

What’s the difference between G00 and G01?

G00 moves at the machine’s maximum rapid speed and ignores the feed rate — use it for positioning only.

G01 moves at the feed rate you specify with the F command — use it whenever the tool is cutting material.

Does G01 need a feed rate on every line?

No. G01 is modal and so is the F command — both stay active once set. You only need to specify a new feed rate when you want to change cutting speed.

Can G01 move multiple axes at the same time?

Yes. If you include X, Y, and Z values on the same G01 line, the machine coordinates all three axes to move in a straight diagonal path to the target position.

Is G1 the same as G01?

Yes, they’re identical. The leading zero is optional and most modern CNC controls accept both formats.

G00 Code: CNC Rapid Traverse Explained with Examples

March 1, 2026 by Brandon Fowler

G00 is the rapid traverse command in CNC G-code. It moves the machine at maximum speed — ignoring any programmed feed rate — along any combination of the X, Y, and Z axes.

It’s one of the first codes you’ll see in almost every CNC program.

Key Takeaways

G00 moves the machine at maximum speed — no cutting, no feed rate control

Use it to position the tool before a cut, after a tool change, or when moving to a safe height
Never use G00 while the cutter is in contact with the part
G00 is modal — it stays active until you switch to G01, G02, or G03

G0 and G00 are identical — the extra zero is optional

G00 – At A Glance
Function	Rapid Traverse (position at maximum speed)
Format	G00 X__ Y__ Z__
Type	Modal (Group 1 – Motion)
Cancelled by	G01, G02, G03
Feed rate	Ignored – machine runs at maximum rapid speed

WHAT DOES G00 DO?

G00 puts the machine into rapid traverse mode, sometimes referred to as rapid travel. When active, the CNC ignores any feed rate set with the F code and instead moves at the machine’s maximum speed. You can move any combination of the X, Y, and Z axes in a single G00 block.

Because G00 is a modal code, you don’t need to repeat it on every line. Once active, it stays on until you switch to another motion mode — G01 for linear cutting, G02 for clockwise arcs, or G03 for counterclockwise arcs.

CODE EXAMPLE — Rapid to Start Position

G90 G54 (Absolute positioning, Work offset 1)
G00 Z1.0 (Rapid Z to safe height)
G00 X1.5 Y2.0 (Rapid to XY start position)
G43 H01 Z0.1 (Tool length comp, move to clearance plane)
G01 Z-0.5 F10.0 (Linear feed into the part — cutting begins)

G00 is only used while the cutter is clear of the part. G01 takes over the moment cutting starts, where feed rate control actually matters.

G0 VS G00 — IS THE EXTRA ZERO REQUIRED?

No. G0 and G00 are read identically by the CNC controller. The leading zero is a formatting preference, not a functional difference.

Textbooks and formal reference materials tend to use G00 while many programmers will use G0 to save a keystroke. If your shop has a standard, follow it — otherwise use whichever you prefer.

WHEN TO USE G00

G00 shows up constantly throughout a CNC program. Use it any time you need to move the tool quickly and there’s no cutting happening including:

Positioning to the start of a cut after a tool change
Pulling Z up to a safe clearance height between features

Moving to the tool change position (often combined with M05 and M09)
Repositioning to a new XY location between holes in a drilling pattern

COMMON MISTAKE – Cutting with G00

Never use G00 while the tool is in contact with the part.

Rapid traverse gives you no control over cutting conditions — the machine will move at full speed regardless of material, chip load, or tool diameter. The result is usually a broken tool, a scrapped part, or a machine crash.

Always switch to G01 (or G02/G03) before any cutting motion.

G00 FORMAT

Specify the destination coordinates for any axes you want to move:

G00 X__ Y__ Z__

You don’t need to include all three axes. These are all valid G00 commands:

G00 Z1.0  (move Z only)
G00 X3.0 Y4.5   (move X and Y simultaneously)
G00 X1.0 Y2.0 Z3.0  (move all three axes)

Because G00 is a modal code, you don’t need to repeat it on every line. If G00 is already active, the next line with coordinates will also execute as a rapid move.

IMPORTANT CONSIDERATIONS WHEN USING G00

Units — Inches or Millimeters

Make sure G20 (inches) or G21 (mm) is set before your G00 command. Moving 10 inches instead of 10 millimeters is a significant difference — and the machine won’t warn you.

Absolute vs. Incremental Mode

How the controller interprets your coordinates depends on whether you’re in G90 (absolute) or G91 (incremental) mode.

Absolute (G90): coordinates are measured from the program zero. G00 X3.0 Y2.0 always moves to the same fixed location.
Incremental (G91): coordinates are measured from the current position. G00 X3.0 Y2.0 moves 3 inches in X and 2 inches in Y from wherever the tool is now.

The images below show the difference between the absolute and incremental positioning modes. The numbers in parentheses are the locations given to the the machine to make the move.

Most production programs run in G90. Check your setup block to confirm which mode is active before editing any G00 lines.

Know Your Path — Check for Obstacles

Before running a G00 move, think through the full path from start to finish. Where is the tool now, where is it going, and is there anything in between such as clamps, fixtures, the part, or the machine table itself.

G00 moves fast. There’s no time to react if something is in the way.

Machine Movement Behavior

Not all CNC machines behave the same way during rapid moves. Most will move all three axes simultaneously, which produces a straight-line path. Some machines move axes one at a time or at different speeds, producing a “dog-leg” path where the tool doesn’t travel in a straight line.

COMMON MISTAKE — Dog-Leg Movement: Don’t Assume a Straight Line

If your machine runs X, Y, and Z at different rapid speeds, a move that looks diagonal on paper can actually travel in a stepped path — potentially colliding with a clamp or part feature that a straight-line move would have cleared.

When in doubt, break the move into separate single-axis rapids or test at reduced rapid override before running full speed.

illustration of dog leg movement on a CNC machine

HOW TO CANCEL G00

There’s no dedicated cancel command for G00. To exit rapid traverse, switch to another motion code in Group 1 such as:

Using any of these codes will turn G00 rapid movement off and switch to the new movement mode.

G00 VS G01 — WHAT’S THE DIFFERENCE?

G01 also moves in a straight line, but at the feed rate set by the F code. G01 is the code used for cutting in a straight line. G00 is for rapid movement.

The rule is simple: if the tool is touching the part, use G01. If it’s not, G00 is faster.

OTHER RELEVANT CODES

The codes below are used with the G00 code or commonly found very close to a G00 command in the CNC program:

FAQS

What is the difference between G00 and G01?

G00 moves the machine at maximum rapid speed with no feed rate control — it’s for positioning, not cutting. G01 moves in a straight line at the feed rate you specify with the F code. Use G01, G02, or G03 whenever the tool is in contact with the part.

Can I use G00 to cut material?

No. G00 ignores the feed rate and moves at the machine’s maximum speed. Using it while cutting gives you no control over chip load, surface finish, or tool load — and will almost certainly break the tool or damage the part.

Does G00 move in a straight line?

It depends on the machine. Most modern CNC machines move all axes simultaneously during a rapid, which produces a straight-line path.

However, there are still many older CNC machines in use and some machines move axes independently or at different speeds, creating a “dog-leg” path. Check your machine’s documentation or test at reduced rapid override if you’re unsure.

What cancels G00?

Any other motion code in Group 1 will cancel G00 — typically G01 (linear feed), G02 (clockwise arc), or G03 (counterclockwise arc). There’s no dedicated cancel command like there is for canned cycles.

Is the Resparked Customizer Worth the Price? An In-Depth Review

March 1, 2026September 3, 2025 by Brandon Fowler

Engraving can be a relaxing and rewarding craft.

With the right engraving tool in your hands, you can finish creative tasks with ease.

And it’s a terrific way to personalize something generic with a fun crafty hobby.

Engraving tools come in a wide variety of styles, sizes, and capabilities. It’s important to find the ideal one at is ideal for your project.

The Customizer by Resparked is an engraving pen that is more than capable of meeting most people’s needs. That’s why it’s a popular choice among home crafters and those who like to try out new tools for art.

The Customizer’s durability, power, compactness, and exceptional value for money make it an excellent professional etching tool suitable for all materials, including glass, wood, and metals.

Best cordless engraving pen

Resparked Customizer

culiau customizer in box with engraving bits

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About the Resparked Customizer

For beginners, the Resparked Customizer Engraving Pen is excellent. Because the tool is so light, engraving is as simple as using a pen.

box/packaging for the culiau customizer — It comes in a surprisingly nice box. Makes a nice first impression

It’s easier to move around the Customizer than say a corded Dremel engraver.

Don’t get me wrong, it will still take practice to get a nice, finished product, but the Customizer is easier to use than some of the other bulkier engraving pens on the market.

culiau customizer compared to sharpie, pen and pencil — Size comparison of the Customizer

The Customizer is roughly the size of a regular marker. The textured grip and light weight make controlling the engraver while in use a snap.

You can sketch with it just like a normal pen or pencil.

The flexibility of this tool makes the job as simple as drawing on paper. It works well on wood, including hardwoods, glass, and metals such as steel, silver, and others.

The Customizer comes with a rechargeable battery and a USB charging wire. The run time is about 2 hours. And trust me 2 hours is more than enough time. Unless you are super experienced, your hand it going to get tired well before the 2 hours runs out.

charging port and cable of culiau customizer — Charging port and cable

Also included is a large selection of engraving bits. They come in a variety of shapes and sizes which means you won’t need to pick up any extras for the Customizer right away.

Unless you plan to use it almost daily, there is a good chance you won’t need to get any more bits ever because the assortment that comes with the Customizer is well rounded.

The engraving pen includes an LED display indicator, which shows you the battery level and speed of the tool.

One of the biggest indicators of the quality of the Customizer is the feel of the tool. This is a well built tool that feels good in the hand.

It is ergonomic, lightweight, and small. Because of this it is exceptionally comfortable to use and handle. The Customizer truly is a pocket-sized engraving machine.

The quality comes with a price though and the Customizer does cost more than some of the other engraving pens on the market. However, many of those cheaper engraving pens aren’t built as well. Often they just don’t feel good in your hand.

If you plan to use it a lot, I recommend going the Customizer from Resparked and avoiding all the generic copycats.

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How to use the Resparked Customizer

1. Safety first!

Above all, make sure you think safety first with any power tool. Proper eye protection. Consider gloves and a dust mask as well depending on the materials you plan to work with.

2. Use proper lighting

Nobody’s idea of a good time is engraving in the dark – and it’s not safe or productive.

Make sure your workplace has adequate light and that it is placed above or in front of you so that your head and shoulders don’t create a shadow on the work.

Proper lighting will make it much easier to see the fine details that you are creating on your workpiece.

3. Work on a clean surface

Before you begin, be certain that the surface you will be working on has been well cleaned.

Some materials can be cleaned with soap and water, others require special cleaning chemicals. Start with soap and water, it will work for most materials.

4. Use a template

Consider making a paper template to guide you. This helps in the beginning when you may lack the courage to do it all freehand.

Print out your design to trace or outline

It’s a good reference.

5. Practice

Just try.

If you want to learn it, then use it!

Practice different words and symbols on a piece of scrap material if you have it. Your first few designs will probably be rough. .

Another key point is to make sure you practice with the type of material you plan to work with. In other words, if you want to engrave on sea shells then find some to practice on.

Frequently asked questions

What kind of material can the Customizer work with?

an engraved piece of glass — An engraved piece of glass

The Resparked Customizer is capable of working with a wide range of materials including:

Wood
Plastic
Metal
Glass
Leather
Stone
Shells
Clay

Does the Customizer use standard Dremel style bits?

Unfortunately, the Customizer does not take Dremel bits straight out of the box. For an added cost, you can purchase an adaptor that will allow you to use them however.

How is customer support?

In my opinion good customer support says more about the product than just about any other feature.

Resparked has excellent customer support through email. [email protected] is their address and in my experience they are quick to answer any questions you might have, even if you just need tips for using your new tool.

Best Engraving Pens for Every Budget & Material

Best Engraving Pens for Every Budget and Material

March 1, 2026September 3, 2025 by Brandon Fowler

Engraving pens come in a wide range shapes, sizes and capabilities. You want to find the one that is just right for you project.

As you read our guide to the best engraving pens, make sure to keep your planned project in mind to determine what tool will work best for you.

Some applications such as jewelry engraving will benefit from a smaller tool for more precise strokes. Other materials such as metal or glass will engrave better with a more powerful tool such as one of the engravers by Dremel below.

No matter what you are working with, we have laid out the best tools on the market and an extensive list of items at the bottom of the article for you to consider when looking for your right fit tool.

Name	Awards	Where to Buy
Culiau Customizer	Best Overall Cordless Engraving Pen	Check Price
Tidalpool Easy Etcher	Best Budget Cordless Engraving Pen	Check Price
Tacklife PCG01B	Best Value Cordless Engraving Pen	Check Price
Dremel 290-01	Best Corded Engraving Pen	Check Price
IMT Scriber	Best Manual Engraving Pen	Check Price

Best Overall Cordless Engraving Pen

Resparked Customizer

Pros

Easy to handle and use
Customer service
Plenty of included bits

Cons

Not the cheapest option

The Resparked Customizer Engraving Pen is excellent choice for novices. Because the tool is so light, engraving is as simple as using a pen.

Don’t get me wrong, it will still take practice to get a nice, finished product but the Customizer is easier to use than some of the other bulkier engraving pens on the market.

The Customizer is roughly the size of a regular marker. The grip and light weight make controlling the engraver while in use a snap.

You can sketch with it just like a normal pen or pencil.

One of the biggest indicators of the quality is the feel of the tool. This is a well-built tool that feels good in the hand.

The flexibility of the Customizer makes the job as simple as drawing on paper. It works well on wood, including hardwoods, glass, and metals like steel, silver, and others.

It is ergonomic, lightweight, and small. Because of this it is exceptionally comfortable to use and handle. The Customizer truly is a pocket-sized engraving machine.

The quality comes with a price though and the Customizer does cost more than many of the other engraving pens on the market. The cheaper engraving pens aren’t built as well, but if you only plan to use it for the occasional project then it might not be a big deal.

If you plan to use it a lot, I recommend going with an engraving pen that is a step above such as the Customizer from Resparked and skipping all the generic cheapy ones.

Check Current Price

Best Budget Cordless Engraving Pen

Tidalpool Easy Etcher

Pros

Lightweight
Easy to control
Included stencils

Cons

Underpowered

The Easy Etcher is an excellent engraving pen for beginners. The tool is so lightweight that engraving with it is as close to using an actual pen as you will get. The Easy Etcher is actually about the size of a standard marker.

The rubberized grip also helps keep the engraver under control while using it. While the 12,000 RPM speed may seem under powered when compared to other engraving pens, it actually helps keep the tool stable during use.

Runtimes will vary depending on the type of material you are working with, but the Easy Etcher runs on AAA batteries which means there is no waiting around for the tool to recharge. The batteries aren’t included but other extras are.

The Easy Etcher comes with 10 sets of stencils that make engraving text or designs on your material a piece of cake. It also comes with a nice starter selection of bits that allow you to create a variety of textures and finishes.

The Easy Etcher won’t be the be all, end all for engraving every material but it is a great tool to get you started without breaking the bank.

Check Current Price

Best Value Cordless Engraving Pen

TACKLIFE PCG01B

Pros

Good power

Cons

Charge time

While the TACKLIFE PCG018 is not as nimble as the Easy Etcher it does a good job of making up for it in the power department. With similar price points, it would be wise to determine whether power or maneuverability is more important to you.

The PCG018 has 3 speed settings of 5, 10 and 15,000 RPMs. This means it will work well for a variety of materials.

This TACKLIFE engraving pen is cordless and rechargeable. It charges over USB which has some benefits and drawbacks.

The charge time is fairly long at 2 hours but with a runtime of 90 minutes it lasts long enough to complete most jobs.

Additionally, the tool comes with 31 different accessories for engraving, sanding and finishing along with a case to contain them all. Two collets to accommodate different bit sizes of 3/32” and 1/8” is also a nice addition.

The TACKLIFE PCG018 is a solid choice when it comes to cordless engraving pens.

Check Current Price

Best Corded Engraving Pen

Dremel 290-01

Pros

Adjustable depth setting
Warranty

Cons

Cost

The Dremel 290-01 is different than most of the other engravers on this list. Instead of being a rotary engraver, it has a vibrating tip that moves in and out. Basically, it operates like a mini jackhammer.

Corded engraving pens like this Dremel have some advantages and disadvantages.

Being corded means that you are tethered to your power outlet and it can be slightly cumbersome to work with the power cord snagging on objects in your work area. The 290-01 is pretty lightweight though which makes maneuvering it around your workpiece a little easier.

A nice benefit of using a corded engraver is that you won’t ever run out of power. This is helpful for harder materials that may take multiple passes to get the amount of engraving you desire.

The power of the 290-01 is controlled with a dial that allows five depth settings. This works well to adjust for different material types such as wood or rock. All that power comes with the side effect that the tool is quite loud when running. You should expect it to be noisy. It is a power tool after all but take note that the other tools on this list are quieter.

There are a couple minor downfalls for the 290-01. The biggest one is that the bit can be difficult to install. The set screw that locks it is tiny and it can be challenging to work with.

Also, the provided stencil comes in handy but is somewhat lacking. Many other engravers come with a wider variety of stencils so keep in mind that you may want to purchase some extra stencils if you plan on engraving a lot.

On the plus side, just like this engraving pen’s cordless counterpart, the Dremel 290-01 comes with a two-year warranty which is well above what most competing engravers come with.

Overall, the Dremel 290-01 is a solid engraving pen. A couple minor inconveniences are balanced nicely by the higher, non-stop power that comes from being always plugged in.

Check Current Price

Best Manual Engraving Pens

IMT Scriber

Pros

No power required

Cons

Doesn’t engrave as deep

If all you need is something basic and reliable for engraving then the manual scriber from IMT may be your best bet.

It requires no batteries or power cord. The tool is extremely lightweight and its tungsten carbide tip will engrave a large variety of materials including steel, ceramics and glass. If you are working with plastics though, a powered tool would be a better choice.

The IMT scriber will actually perform an operation that is more akin to scratching your material than actually engraving it. For many use cases, this is more than enough. Just keep this in mind when choosing your engraving pen.

It also comes with extra tips in case one snaps. They are somewhat brittle because they are so hard. They aren’t fragile but can break if you aren’t dropped or handled roughly. Luckily, the scriber comes with a protective cap that will help shield the point from damage.

The IMT scriber is definitely more low tech than some of the other engraving pen options available but if all you need is a simple engraver then it may be a great choice at a cheap price.

Check Current Price

Things to consider when buying an engraving pen

Safety

Remember that these tools can be dangerous, especially to your eyes. Be careful handling them and use eye protection to protect you from things such as flying chips or broken bits.

Corded vs cordless engraving pens

Corded engraving pens generally have more power than their cordless counterparts. The downside is that the cord can get in the way and make the tool more difficult to maneuver. The easiest engraving pens to use are those that are lightweight and battery operated.

Cord length

If you choose to use a corded engraving pen to have more power, keep in mind that the length of the power cord is very important. If the cord is short, then make sure that you have an extension cord handy because some of the power cords can be very short.

Speed

RPMs do not equal power. Being able to adjust your RPMs over a wider range is more beneficial than simply having a higher RPM overall. Different materials will require different RPMs. In general, materials such as glass or metal which are harder will benefit from a higher RPM and softer materials will engrave better at lower RPMs.

Bits and accessories

It is a nice bonus for an engraving pen to come with a good selection of bits and accessories but not a necessity. There are many bit or accessory kits available that allow you to perform different types of engravings or finishing to your piece for a fairly cheap price.

Extra bits aren’t required to start but before too long you will definitely want to expand your bit collection if your engraving pen doesn’t come with many. Different bits will allow you to different styles of engraving.

Battery

If you go the cordless route, make sure you find a tool that charges quick and has a long runtime.

Cheaper tools tend to run off standard AA or AAA batteries which means they can run out of power quickly but also that more power can easily be on standby. Keep extra batteries nearby but consider the amount of power you will need for your project when choosing which engraving pen to go with. Harder materials require more power.

Warranty

Pay attention to the length of the warranty for your tool. Just like many other power tools, a good warranty is a solid indicator of the quality of the tool. This doesn’t mean that good tools don’t come with shorter warranties, just that it is something to be mindful of.

Stencils

Stencils can be very important for getting the correct design on your part. There are many different stencil kits available but it is definitely a bonus to have a couple to start with. Creating visually appealing designs freehand is going to take some practice so having a template to follow when getting started will be helpful.

Engraving vs cutting

Engraving pens are just that, engravers. They generally are not meant for cutting. If you are looking for a tool that is capable of doing more than simply scratching the surface of a part, then you will want to look into something with more power like the various Dremels or other higher power rotary tools.

For more information check out these related articles:

Guide to Becoming a CNC Operator

March 1, 2026September 9, 2024 by Brandon Fowler

Overview

Being a CNC operator is easily the simplest of all CNC jobs. A CNC operator is typically an entry level position and they are tasked with keeping the machines running and constantly making parts.

cnc operator pushing button on control panel

In most cases, someone else will program and setup the machine while an operator is asked to keep it between the lines. This often means checking parts in some fashion as they come off the machine and occasionally making small adjustments to keep everything within the allowable tolerances.

CNC operators are often referred to as button pushers. Quite honestly, operating a CNC isn’t the most highly skilled position. As a result, the pay isn’t that high, but most will find it still beats working retail and isn’t nearly as backbreaking as something you might find in one of the construction trades.

So, let’s jump right in to some of the most frequently asked questions about becoming a CNC operator.

What does a CNC operator do?

A CNC operator pushes buttons to keep the CNC machines running while performing basic inspection of the machined parts.

As an entry-level position, all of the skills necessary for a CNC operator to possess would be taught to a new employee. Any experience or knowledge that an applicant bring with them would be icing on the cake.

Operators will be expected to do simple math such as adding and subtracting. Additionally, they will use measuring gauges such as micrometers, calipers, a pocket comparator and often dial indicators.

mitutoyo digital caliper — A digital caliper

anytime tools 1-2" micrometer — Typical outside micrometer

Basic hand tools including screwdrivers, mallets and deburring tools will get everyday use as well. The real benefit of being a CNC operator is that it can be a great stepping stone to an extremely in demand profession once you have expanded your skillset and advanced to the level of CNC setup and/or programming.

Experience with blueprints, trigonometry or handheld measuring equipment such as micrometers and calipers would be very sought after for any company.

Typical CNC operator job description

MachinistGuides.com is seeking a quality-oriented CNC Machine Operator to join our dynamic team.

The CNC Machine Operator will work with other team members and report to the Shop Manager. This role is responsible for reading blueprints, checking finished parts, and operating CNC mills and/or lathes.

The CNC Machine Operator will:

Safely operate a CNC machine to create precision components
Read and interpret blueprints, diagrams, sketches, and verbal instruction
Maintain pace of production to meet scheduled demands
Safely load and unload CNC production equipment
Have the ability to lift 50+lbs and stand for several hours

Desired Skills:

CNC machine operator/manufacturing experience
Thorough knowledge of standard manufacturing concepts, practices, and procedures
Have a strong work ethic and a positive attitude
Attentive to detail and instruction

Compensation commensurate with experience. A list of benefits which may include paid time off, 401k, medical, dental, life insurance, and/or holidays.

CNC operator skills

basic dimensions of bolt hole circle on blueprint — Blueprint example

Blueprint reading
Simple math including addition and subtraction of decimals
Hand tools
Handheld measuring equipment use
Some light trigonometry

Check out our Beginner’s Guide to Blueprint Reading to gain a leg up on the competition.

Our guide to machinist lingo will help you talk the talk at your new job as well.

How much does a CNC operator make?

According to GlassDoor.com, the average pay for a CNC operator is $38,490 per year. With a typical 40-hour week that comes out to $18.50 an hour.

Keep in mind that pay will vary by region, but this should give you a good idea of where you will start. The nice thing about CNC and machining work is that there is often quite a bit of room for growth.

For reference, CNC programmers can often make $30+ an hour.

How long does it take to become a CNC operator?

Being a CNC operator is an entry level position and as a result, you can be a CNC operator on your first day on the job.

You might not the most productive employee on day one, but you will be tackling the normal everyday responsibilities of more experienced operators.

Is it difficult to learn how to be a CNC operator?

CNC operation is not a difficult job to learn. As an entry level position, the skills needed to be a great CNC operator can be learned in a pretty short amount of time.

Is being a CNC operator stressful?

Generally speaking, CNC operation is not a stressful job. Of course this will vary from company to company but because the position is entry level, there is very little responsibility on the operators part.

It will be possible to find some businesses that work with a very heavy “produce, produce, produce” mentality and in these cases, the job can get more stressful. This is more of a product of the management style than the actual position itself so make sure to do some research online to check out some reviews for any potential employers.

Is being a CNC operator boring?

cnc operator inspecting part in front of machine

This is a very subjective question, but I believe many would find the position boring. A CNC operator job will usually be fairly repetitive while not being overly difficult mentally or physically.

The good news is that if your are looking for something to keep things a little more interesting then there will often be opportunities for advancement if you are willing to learn and put in a little effort.

You should also know that boring is also a term for precision machining of a hole by a machine such as a CNC mill or lathe.

Do you need a degree to be a CNC operator?

Being a CNC operator does not require a college degree in any form. Local community colleges often offer certificate programs or crash course type coursework that will be looked upon very favorably for any new hire.

Many companies however will require a high school degree or equivalent. Larger companies are usually the ones who have this requirement. Smaller shops are generally more lenient.

What kinds of certifications and training are available to become a CNC operator?

Training, courses, classes, and certifications are available at colleges across the country with many community colleges leading the way.

Check out your local community college’s website to see if they offer training that may be beneficial. You will likely be surprised at the number of different options they offer.

Another valuable resource is your states manufacturing extension program. These organizations are usually aimed more at helping businesses with workforce development, but they often offer subsidized training that can give you a huge leg up in the job market.

YouTube is a great resource as well and there are thousands of high-quality videos out there to teach you all about every aspect of CNC work.

If you want a more structured approach, then check out our post on the best CNC and machining books. Many of these books are the same reference material that the college classes mentioned above will use.

What should you put on a resume to get a position as a CNC operator?

To get a job as a CNC operator make sure to mention any of the following items that may apply:

Math skills, especially anything related to trigonometry
Blueprint reading experience of any kind
Mention your attention to detail
Describe how reliable and dependable you are

Tips for finding a good position as a CNC operator

Research, research, research.

Actually it’s not that hard. A single research is probably enough. It is actually pretty easy to find a good job as a CNC operator.

Look for company reviews on sites such as Indeed or GlassDoor. Take it all with a grain of salt but in my experience, any company who has more than a few reviews will be pretty easy to determine the overall “vibe” of the business.

Look for a company that stresses quality over quantity and you will be headed in the right direction.

For more information check out these related articles:

Beginner’s Guide To Reading Machine Shop Numbers & Values

March 1, 2026September 9, 2024 by Brandon Fowler

Confused? If you’re reading this page then I’m pretty sure you are. Dealing with numbers, values and calculations when machining or 3d printing can be hard for those just starting.

The lingo and terminology used by many people both online or at a new job can be hard to understand. My hope is that after this quick lesson in dealing with machine shop numbers, you will not only be comfortable reading your numbers and measurements but also will know how to perform some simple calculations using them.

Let’s begin

First we need to understand what the numbers we are working with represent.

Whether they are a reading on a micrometer, a spec on a blueprint or a stack of gage blocks, the goal is the same.

We need to know how to read them and work with them.

Below is a graphic that shows the name (including machine shop lingo) for different values.

Pay attention to how far each number is from the decimal place when looking at the chart.

Please note that not everyone will be working down to millionths of an inch but I included them for reference. Many will only work down to the the values shown in this table.

Value	Machinist Lingo	Technical Math Term
0.001″	Thousandth or Thou	Thousandth of an Inch
0.0001″	Tenth	Ten Thousandth of an Inch

Keep in mind that all these numbers and terms apply to imperial units (inches).

How to say the value

Machine shops usually speak in terms of thousandths of an inch. Because of this when we describe the value to someone else we will read it a little different than you might expect.

As noted above, if we give the example of 7.489136″ a machinist would describe the value as 7 inch, 489 thousandths, 1 tenth, 36 millionths.

Read that last sentence over a couple times to really understand the terms your typical machine shop speaks in.

As a note, not all machine shops or hobbyists will deal in millionths of an inch and some might not even work with tenths but I have included them for reference.

Note: Thousandths of an inch is often abbreviated as “thou” especially when discussing values verbally.

Machine shop number reading examples

Below are some more examples to show how machinists communicate values:

Value	Machinist Lingo
1.325″	1 inch 325 thousandths
0.5001″	500 thousandths 1 tenth
0.021	21 thousandths
0.6532″	653 thousandths 2 tenths
9.792345″	9 inch 792 thousandths 3 tenths 45 millionths

Gage blocks

A common scenario for someone new in a machine shop is learning how to set up a stack of gage blocks.

I’m not going to show you how to pick the right gage blocks for your stack here. If you need those instructions then head over to Starrett’s website. They have great instructions that show you how to select your gage blocks and make a stack of a specific height.

The link also contains information related to the use and care of your gage blocks. Take care of your gage blocks people, those things are expensive.

How to setup calculations

Now I said I would show you how to work with these numbers, so let’s demonstrate how to do that.

The important part when dealing with numbers or values in a machine shop context is to line up the decimal point. Below you will see some examples of addition and subtraction of numbers:

Simple calculation examples

For practice, let’s list out how to say those answers!

Value	Machinist Lingo
1.610″	1 inch 610 thousandths
0.7206″	720 thousandths 6 tenths
0.6249″	624 thousandths 9 tenths

There aren’t any other special tricks here. Once you line up the decimal places everything else is just like you learned early in school. Also consider yourself lucky we have calculators.

That’s it. Now you should know how to speak in terms that a machinist would understand and use the values in simple calculations.

If you need more in depth training when it comes to machine shop math, check out the training linked below. It breaks all the hard subjects down into bite sized pieces to make them easy to understand.

Ready to master machining math?

Get the tips and tricks you need to master the math needed for CNC and manual machining. Includes easy-to-follow guidance to make learning the math you need to succeed a breeze!

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Complete Guide to Comments in G Code

September 9, 2024 by Brandon Fowler

a cnc machine running with g code overlaid

What are g code comments?

Comments in CNC g code are portions of the program that are ignored by the CNC controller and/or help the machine operator understand the program.

There are many different machine manufacturers and they can each have their own format for handling and identifying comments. In other words, what works on one machine may not work on another.

When in doubt try to find a manual or research your specific brand of CNC. We have outlined some of the most common CNC manufacturers and how they call out comments in the table below.

You can see that the two most common ways to identify a comment are by enclosing it in parentheses () or placing a semicolon symbol ; before the comment.

How to insert a comment into a g code program

The table below lists the symbol or character that is used to identify g code comments on a specific line of the program.

Take note that when parentheses () are used, everything between the open and closed parentheses will be ignored.

When the semicolon ; is used, all code after the semicolon on that line will be ignored and treated as a comment. Placing a semicolon inside a parentheses will not make the machine ignore the rest of the line, only what is inside the parentheses in this case will be ignored.

Remember, there are dozens or possibly hundreds of machine tool manufacturers and some may not adhere to these rules but this guidance will work for the majority of machines.

Machine Control Manufacturer	G Code Comment Character
Fanuc	Parentheses ()
Haas	Parentheses ()
Heidenhain	Semicolon ;
Hurco	Parentheses ()
Mitsubishi	Parentheses ()
Sinumerik (Siemens)	Semicolon ;
Yasnac	Parentheses ()

Ready to master CNC programming?

Try the free 30 minute intro course to see how simple and easy G code can be. Take the shortcut to becoming a G Code Master today!

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What should be included in a g code comment?

Comments can include anything that can help to operator or setup person to better understand how the program is operating.

Placing comments at key moments in the program can be a great way to help an operator. Letting them know if they need to perform an action or if the program is about to start a new operation (switching from roughing to finishing or starting to drill a set of holes) can be extremely helpful.

The best practice is to be brief but provide enough info. You don’t want to write a book and clutter up the program, but too little information can leave a person guessing or assuming what is happening in the program.

Creating good comments can help someone who isn’t highly trained in reading g code but they can also help you when you go to troubleshoot the program or try to edit or improve it later on down the road.

Where should you put comments in your CNC program?

In general, g code comments should be placed at the end of the program line to describe the current action. Some machines allow comments, specifically ones in parentheses (), to be added in the middle of the line.

I recommend avoiding this practice as much as possible. It can cause issues with some machines. Sticking with a semicolon or parentheses at the end of the line will help ensure your program is the most compatible with a wider assortment of machines.

As we noted above, it is also a good idea to include comments at the start of a new section of your program.

Tooling descriptions, offset information and descriptions of the operations being performed are all great info to include in the comments at the start of a new section.

A block of comments at the start of your program is a welcome addition that many CAM programs will automatically insert with information such as the program creators name, a date or revision of the program and miscellaneous other information.

When should you use comments in your g code?

Comments add to the size of the CNC program (not as much of an issue with newer machines) and also clutter up the code.

Use them sparingly and in the important places. You don’t need to comment ever move.

Comments work great at the start of program sections to help operators know what to expect or what is expected of them.

Ready to master CNC programming?

Try the free 30 minute intro course to see how simple and easy G code can be. Take the shortcut to becoming a G Code Master today!

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How to Learn CNC Programming [Best Resources]

September 9, 2024 by Brandon Fowler

What is CNC programming?

CNC programming is the process of creating and running a program consisting of G code in a CNC machine to move the machine and control its functions.

There are a large range of CNC machine types available, from industrial mills and lathes to home machines such as 3d printers, laser engravers and CNC routers.

All of these CNC machines use the same G code language to control the machine.

How difficult is it to learn CNC programming?

Learning basic CNC programming is fairly easy. It involves learning how the CNC machine will react to a series of codes. Most of the codes are easy to remember with a little practice (F for feedrate, S for spindle speed) and for any of the harder to remember codes, cheat sheet type references are usually not too far away.

Learning advanced CNC programming will take more time. Practice and repetition help, as does attending local training programs or completing an online training course.

When learning CNC programming expect to apply math skills, learn to read manufacturing blueprints and work with specialized computer programs.

Ready to master CNC programming?

Try the free 30 minute intro course to see how simple and easy G code can be. Take the shortcut to becoming a G Code Master today!

View Free G Code Course

What are the steps involved in CNC programming?

infographic that shows three steps to making a cnc program

Plan the program

The first step in CNC programming is planning out your program. In this step you will choose the machine and tools that will use to make your part. The operations to create the part (shape part, drill hole, mill slot, etc.) as well as the order of those steps will be determined.

Write the program

Now that you know what you will use to make the part (machine and tools) and how you will make the part (the order of operations), the program can be written.

When writing the program, you will create code either by hand or with the help of software to create the instructions for the machine to run.

In this step, documentation is usually created that lists any special requirements for running the program such as the tooling to be used, offset information, and fixturing information.

Setup the CNC machine

The role of the CNC programmer will sometimes end once the program is written and documented. However, in many machine shops programmers are also responsible for setting up and/or operating the machines too.

Setting the CNC machine up will involve loading the correct tools, setting offsets, loading the program and running a first piece to verify everything is running as planned.

Types of CNC programming

Manual programming

Manual programming is when the programmer creates the G code by hand. This involves controlling all of the machine’s functions and movements through the use of code.

Manual programming of CNC programs is usually only done with very simple programs.

Conversational programming

Conversational programming involves giving the machine specific parameters or dimensions that are required and the CNC machine generates the code for you based on the input.

Conversational programming is a middle point between manual programming and programming with CAD/CAM systems. Conversational programming simplifies the programming of features that may be difficult to program manually.

Conversational programming can allow quicker programming times when compared to CAD/CAM programming options. It also generally requires far less training than what is required to work with CAD/CAM packages.

Programming with CAD/CAM

two computer monitors with CAD-CAM software running — Example CAD/CAM software

The majority of CNC programming today is done with the use of various computer aided drafting (CAD) and computer aided manufacturing (CAM) software packages. These software programs allow the creation of long, complex CNC programs with much less work when compared to manual or conversational programming.

CAD/CAM programs are capable of programming things that wouldn’t be possible with manual or conversational programming. There are many different CAD/CAM software programs available with some of the most common being AutoCAD, Fusion 360, SolidWorks, Mastercam & EDGECAM.

How to start learning CNC programming

Local college/training

One of the best ways to start learning CNC machining is to look for local education resources such as colleges, community colleges, training programs and your state’s manufacturing extension partnership (MEP).

These resources often provide unequaled instruction and hands on use of equipment.

In some areas, companies have created their own training programs which they operate to help educate their local workforce.

Self-guided training

If you don’t have local training options available, there are a large number of resources that allow you to learn CNC machining and programming on your own schedule.

YouTube has a wealth of informative instructional videos and there is an abundance of information available on other online resources such as MachinistGuides.com.

We recommend reviewing our list of the Best CNC and Machining Books to find the best reference material available.

Learning on your own can be daunting, especially when you don’t know where to start. For this reason, we have put together A Roadmap to Learn CNC Programming to help guide you and make sure you focus on the important stuff first.

Online training

For those looking for a more structured approach, there are online CNC training resources and courses available such as GCodeTutor.

The biggest benefit of online training is that it allows you to work at your own pace. The best online training programs will have help resources available as well as quizzes and projects to test your knowledge.

Types of CNC machines

CNC machines used to be extremely expensive machines that only large companies were capable of purchasing.

In recent years, the cost of CNC machines has come down quite a bit. Large scale industrial machines are still available, but they are accompanied by a new generation of machines aimed at hobbyists and makers.

Home/hobbyist machines

CNC routers
CNC plasma cutters
CNC laser engravers
3d printers

Industrial level machines

a cnc mill with multiple fixtures and coolant lines — Industrial CNC

Mills
Lathes
Electrical discharge machines (EDM)

Frequently asked questions

Do you need a degree to get a job in CNC programming?

No degree is needed to become a CNC programmer, although previous training or certifications are looked at very favorably by employers.

Many employers are willing to provide on the job training to teach new employees the skills needed to perform the job.

How long does it take to learn CNC programming?

The basics of CNC programming can be learned in a short amount of time. Learning the basics will only take a few short months.

However, CNC programming is a wide field, and it will take much longer to have a solid understanding of everything that goes into CNC programming.

To become a highly skilled CNC programmer will likely take years. Training programs vary in length from 1-4 years on average. In addition, hands on experience will be needed to truly become a master of the craft. Certainly, anyone who applies themselves and works hard to learn will shorten that timeframe considerably especially when working in a good training program.

Is CNC programming a good career?

CNC programming is a great potential career. There is a high level of demand for skilled CNC workers across the globe. Many experienced CNC programmers and machinists are expected to retire in the coming years and a lower rate of younger workers entering the field has created a high demand for skilled CNC workers.

The demand for skilled CNC workers is so large that many in the CNC industry refer to it as “the skills gap”.

This skills gap has created a good opportunity for anyone seeking a well-paying job in the industry.

What is the salary for a CNC programmer?

According to GlassDoor.com, the average CNC programmer makes about $85,000 per year.

That comes out to about $40 an hour.

CNC programming is similar to other skilled trade jobs and can pay quite well without the need for a college degree. Getting training or certifications will help improve your chances of landing that well-paying position.

What skills does a CNC programmer need?

Because most CNC programming positions require the use of specialized CAD/CAM software, the best programmers have solid computer skills.

CNC programming positions often require math skills as well. Trigonometry, geometry and algebra are all commonly used when programming. Often the computer software will perform the necessary calculations but there are many times where calculations must be verified by hand.

Luckily, most of the math skills only use a limited number of formulas. To get a better idea of the type of math skills involved, check out our Beginner’s Guide to Machine Shop Math.

title image that shows a triangle drawn on a paper with pencil next to it

What other jobs take similar skills to CNC programming?

CNC and machine operators are the closest related job to CNC programming. Often, operators are the ones who will be running the CNC programs.

It is quite common for operators to gain some experience in their machine shop and work their way up to a position in CNC programming.

CNC and machine operator positions are typically much less demanding when it comes to computer and math skills and are a great starting point for anyone interested in learning CNC machining.