How to program a CNC router

Last updated on November 15th, 2022 at 04:03 pm

A CNC machine is a set of computers, CNC machines, and other equipment. The most challenging aspect of a CNC machine is programming it. The process has been more straightforward by using computers and numeric codes. Understanding G-code can assist you in completing tasks more quickly. Wood machining sectors have turned to industrial-grade CNC routers. They are time savings, from stair construction to sign production.

They’re also common in other types of production. These include shaping foam and aluminum honeycomb for aerospace applications. CNC milling machines use rotating bits in various shapes to cut panels and create pockets or complex curved edges in relatively soft materials. Routers use rotating bits in multiple forms to cut panels and create bags with rugged curved edges in relatively soft materials.

CNC routers of all sizes use the same primary X-Y-Z axes to synchronize the tool’s motion to the task. The Y-axis is usually the longest, followed by the X-axis, shorter horizontal axes, and the Z-axis, the vertical axis. The long axis gets support from the racks and pinions that support the gantry. It is supported by linear rails and manipulated by ball screws.

The gantry’s shorter horizontal axis spans its width. Holding the spindle carriage on linear guides and moving it using ball screws. The vertical motion of the spindle is usually also controlled by a ball screw. It can utilize the fourth axis to move the workpiece with the other three axes.

Connecting to PC

A CNC machine can be connected to a standalone PC by CNC machinists. Because the method is simple, no special hardware is necessary to connect a CNC machine to a computer.

System Requirements

You’ll need an RS-232 cable with a 9-pin connector on one end and a 25-pin connector on the other, depending on the type of CNC machine. The cable is set up as a null-modem connection. There is no need for any additional gear.

Software Prerequisites

You’ll need some communication programs to get started. You already have the program you need to communicate if you have a CAM system. (Mastercam, Surfcam, GibbsCAM, etc.) A DNC, such as Predator DNC, is a communications program.

Machine Settings

The only other thing to remember is that the CNC control and the PC’s communications settings must match. The CNC machine control settings are crucial; they must match the PC software.

Using the G programming language

G code is a programming language for CNC machines. CNC programmers employ CNC programming, whereas CAM programmers use the other. CAM programs from CAD drawings can generate G-code, but the end product is still g-code. G-code is the standard programming language for CNC machine equipment used by CNC routers. The language is simple and specifies tool movements using Cartesian coordinates. These are obtained from the origin or point to point (relative) (absolute).

Other codes are available to describe spindle speed and tool selections, among other things. There is software to assist signage design, automatically calculates tool paths, and builds a router program. 3D software is standard for CNC turning and milling. It is not proper for routing operations that produce signage or cabinetry components.

Of course, shapes like honeycomb panels or wood carving can be manufactured using a CNC router, and a 3D CAD program is helpful for them. The software calculates all cut parts, dados, and other details for custom cabinetmaking. Optimizing the cut list to maximize material use before sending G-code instructions to the CNC router.

There are other options–Heidenhain, Mazak, Shopbot. Others have proprietary formats–your machine’s CNC controller most likely runs g-code. Some proprietary-format devices can also run g-code. CNC uses it as its lingua franca (working language). To make a part program on a CNC machine, you use a G-Code file to inform you how to make the part program.

G codes meaning

G00 Fast move

G01 Linear interpolation

G02 Circular Interpolation CW

G03 Circular interpolation CCW

G04 Dwell Dwell

G09 Exact stop check

G10 Data setting

G11 Data setting cancel

How to set your tool length

Place the touchpad on the table in a secure location. If possible, select an area that you can easily reuse in the future and that will not alter.

Remove the collet nut, tool, collet, and tool from a tool holder and leave the chuck with an empty tool holder.

Place this empty tool holder over the touchpad. Choose “Tools,” then “Empty” from the drop-down menu; You will use this to determine the reference point.

Change your measuring instruments to the one you’ll use first. You can accomplish this either manually or automatically. If you’re doing it manually, be sure the software recognizes the tool in the chuck.

Place the tool over the touchpad in the exact location as the empty tool. Leave anywhere from 0.1″ to 1″ of space between the instrument and the pad.

Click TOOL on the main page, then “Learn tool #x,” where X is the number of the tool currently in the chuck. If x isn’t the tool in the chuck, it wasn’t detected correctly, and it won’t prepare properly.

The tool will gradually lower until it reaches the pad, after which it will retract. The technique will get mastered.

Measure the rest of the tools until the software has a complete picture of their lengths.

When you replace the tool due to wear or a need for a different device, you must teach only the new tool and prepare it with the pad in the exact location. If the pad has moved or you don’t recall where it was, re-learn the empty spot first.

CNC Code basics

G-code is an alphanumeric pattern. The logic of a standard G-code command is as follows:

N.. G.. X.. Y.. Z.. F.. S.. T.. M.. with the denotations representing numbers

N is the program’s line number; it ensures that the program runs in a logical order.

G denotes a motion in the following Cartesian coordinates. There are several G commands (thus the term G-code), and they differ from machine to machine, so consult your controller manual. Nonetheless, G-codes comes in three categories:

G00 – used for non-cutting, fast movements.

G01- typically used to cut material and is utilized for linear movements at a programmed feed speed.

G02- used for circular motions at a high feed rate.

The X, Y, and Z coordinates are defined using the X, Y, and Z commands. The Z-axis is the “scariest” to program, so proceed cautiously. Crashing a machine spindle is always an expensive remedy. Simulation comes in handy in this situation.

F stands for federate, which refers to how quickly the machine should travel from one location to another. You can measure it in inches per minute or millimeters per minute.

S stands for spindle speed, which indicates how quickly the spindle should rotate in rpm.

T stands for tool selection; most CNC mills today have ten or more tools available for usage.

M is a collection of functions that you can use to turn things on and off, flood coolant, blow air, close machine doors, and more. Every machine has its own set of M instructions, so be sure to study your handbook thoroughly.

The letters I and J represent the Arcs. The arc’s X and Y coordinates and the X and Y distances from the arc start point to the arc center point are required.

For Example:

N24 G01 X10 Y20 Z5 F300 S3000 T1

Breaking it down;

Line 2 of the software states that the spindle will make a feed move (G01) from the starting position of (X0, Y0, Z0) to (X10, Y20, Z5).

Tool 1 (T1) is the chosen tool.

The spindle rpm is 3000, and the feed speed is 300 mm/min (F300) (S3000).

Free CNC router software

The following are some of the Free CNC software

• Carbide Create
• Fusion 360
• Solid works
• Easel
• FreeMill
• LinuxCNC
• Inkscape

Average CNC router programmer salary

CNC programming can be a beneficial skill to have. CNC Programmers earn an average of $54000 per year, according to GlassDoor. When compared to CNC Machine Operators, who earn $42,000 per year, and CNC Machinists, who earn $42,000 per year.

Being a skilled CNC Programmer can significantly increase your earnings based on such figures.