⚠️IMPORTANT: Installing LinuxCNC will completely overwrite your current operating system as well as all data and programs on your computer. The hard drive will be reformatted. Save all g-code and other important files to an external drive before continuing with installation.

Installation on Computer with BIOS firmware – PDF
Installation on Computer with BIOS firmware – DOCX

Installation On computers with only UEFI support – PDF
Installation On computers with only UEFI support – DOCX

Reinstallation On computers with only UEFI support – PDF
Reinstallation On computers with only UEFI support – DOCX

Red Hat, Debian, and Ubuntu are popular Linux distributions, each with different focuses:

• Red Hat (RHEL): Enterprise-grade, subscription-based, known for stability and long-term support. Uses RPM packages.

• Debian: Community-driven, very stable and secure, preferred by advanced users. Uses DEB packages and is often a base for other distros.

• Ubuntu: Based on Debian, designed for ease of use. Popular for desktops and CNC applications like LinuxCNC. Uses DEB packages and apt.

In CNC applications, Ubuntu is commonly used due to its balance of user-friendliness and performance, especially with LinuxCNC which is why we currently use it.

From the CNC operator’s perspective, the underlying operating system is often secondary—as long as it runs your programs reliably and efficiently. In most cases, users interact with Windows primarily to launch software or manage files, and the Linux desktop functions in much the same way. If you’re familiar with Windows, you’ll find the transition to Linux intuitive. The basic actions—navigating, opening and closing programs, moving files and folders—are all similar, with only a few minor differences that are easy to learn.

What truly sets Linux apart is its performance advantage when running CNC software.

When selecting an operating system and control software for Sherline’s CNC systems, we didn’t choose the Linux-based EMC (Enhanced Machine Controller) just because it’s free—we chose it because it delivers superior performance for three key reasons:

1. Focused System Resources

Linux dedicates its full processing power to running the EMC software, without the background interruptions common in Windows. At the time of our evaluation, CNC programs running on Windows could pause unexpectedly during a machining operation due to the system performing internal tasks—leading to unwanted marks or flaws in the finished part.
Some Windows-based CNC systems worked around this by using a second computer to buffer data to the servo drivers, but this added unnecessary hardware complexity and hundreds of dollars in cost. Linux, on the other hand, avoided the issue entirely by providing a stable, dedicated environment for machine control.

2. Developed for Precision by Experts

EMC originated at the National Institute of Standards and Technology (NIST). When the software was released as open-source, it wasn’t user-friendly for most machinists. However, a group of dedicated engineers and skilled hobbyists continued to refine it. Sherline partnered with this community to create a user-ready version of EMC that offered performance and reliability unmatched by Windows-based systems at the time.

3. Advanced Cutter Compensation

When we chose EMC, one standout feature was its robust handling of cutter offsets (G41/G42). At that time, this level of accuracy and control wasn’t available in other software accessible to home machinists and hobbyists. While many modern programs have since improved, EMC continues to offer professional-grade features without the extra cost.

In short, Sherline chose Linux and EMC not for cost savings, but for performance, reliability, and better machining results—all of which directly benefit our customers.

The Sherline CNC system, along with EMC, operates using G-code, the industry-standard language for programming CNC machines. G-code is widely supported by most CAD/CAM software, making it easy to integrate into your workflow.

For simple parts, G-code can be written manually. For more complex shapes, you can design your part in a CAD program and export the file as G-code for use with EMC. If your CAD software doesn’t support direct G-code export, a separate CAM or post-processing program may be required to convert the design.

For more information on G-code and how it’s used with Sherline systems, refer to the CNCinst.htm file included on the Sherline Documentation CD.

The most up-to-date version of the instructions can be found at CNC 7 Instructions. Instructions for Debian systems purchased between January 1, 2005, and September 17, 2009, can be found at CNC 4 Instructions. For those using a system purchased before January 1, 2005, instructions for the 2.xx Redhat version can be found on the Sherline CNC Instructions page.

We have included a number of free utilities that will help you create G-code. They are located in the “Utilities” folder that can be found on your CD. They are all programs that run on your Windows® computer, and the G-code files you generate can be saved in .txt or .ngc format and transferred to your Linux computer to be run. They can also be found on the Sherline website at CNC Links and Resources.

If you’re new to CNC, we strongly recommend reading the Sherline CNC Instructions in full before attempting to machine any parts. These instructions provide a solid foundation for beginners and are especially helpful for those unfamiliar with CNC programming or G-code.

By the time you’ve completed the guide, you should be comfortable writing basic programs and have a clear understanding of more advanced code and operations—giving you the confidence to begin machining with accuracy and purpose.

LinuxCNC Help – Getting Started includes other links to G and M codes for LinuxCNC mill and lathe sample programs, special notes on the tooling page and CNC mill set-up procedure, and more.

Not necessarily. G-code generated by CAD/CAM software may require some manual fine-tuning before it runs properly in EMC—or any CNC control program—because post-processors are typically customized for specific machines, which can vary significantly.

While EMC follows industry-standard G-code conventions, it is up to CAD/CAM software developers to tailor their output to be compatible with EMC—not the other way around. Some manufacturers assign unique functions to unstandardized G-codes, which may conflict with how EMC interprets them. Additionally, Sherline’s simplified CNC system does not support all G-code functions, such as certain canned cycles, M-codes, or inputs like limit switches.

Because of this, it’s important to preview your G-code in EMC’s backplot tool before running the program. If the program stops and highlights unsupported or incorrect lines of code, you’ll need to edit and remove them manually using the built-in editor.

This is why having a basic understanding of G-code is still essential—even if you use a CAD/CAM program to generate it. As EMC (LinuxCNC) becomes more widely used, more software developers are beginning to offer dedicated post-processors for it. However, Sherline has no control over how these third-party companies design their software.

In the absence of a dedicated EMC post-processor, we recommend selecting a “Mazak” or “Hurco” post-processor as a close alternative for 3-axis projects.

Some customers mistakenly believe that a CNC machine can take an image of a part and automatically produce it. This is not possible with any CNC system.
To understand the steps involved in converting a design into a machinable format, please refer to our guide: “What Is Needed to Make Parts on a CNC Lathe?”

That said, there are specialized programs that can interpret an image—such as a photo—by analyzing its light and dark areas and converting them into height data (darker areas are interpreted as deeper cuts). These programs can generate a 3D G-code file that reproduces the image as a machined surface.

One such program is DeskART, which allows users to import BMP, GIF, JPEG, WMF, or TIFF files and convert them into a DXF surface mesh or directly into G-code. You can learn more and download a free 30-day trial at www.deskam.com. DeskAM also offers additional software tools for engraving and CNC design.

You can switch between inch and metric modes in EMC by using the G20 or G21 G-code commands:

• G20 sets the machine to interpret dimensions in inches.

• G21 switches the system to use millimeters.

When you use G21, the software automatically converts your inputs into the correct motion, even if your machine uses inch-based leadscrews. Likewise, G20 allows inch-based programming on a machine with metric leadscrews.

Even if you always program in inches or millimeters, it’s important to explicitly include the appropriate command at the beginning of each G-code file. This is because EMC retains the last-used unit setting, even after the system is shut down.

• On inch machines, always start your program with G20.

• On metric machines, always begin with G21.

This ensures the machine runs with the correct unit system and prevents errors caused by leftover settings from a previously run program.

When launching EMC, be sure to select the correct machine configuration from the desktop:

• For an inch-based machine, choose “CNC Sherline Benchtop Mill (Inch)”

• For a metric-based machine, select “CNC Sherline Benchtop Mill (mm)”

Each configuration file is calibrated for the specific leadscrew pitch of your machine—20 TPI for inch machines and 1 mm pitch for metric machines.
Because of this, you cannot run a metric machine using an inch configuration or vice versa, as the motion calculations will be incorrect.

Sherline has simplified the setup process to get you up and running quickly. Your CNC computer comes with the operating system, control software, driver, and power supply pre-installed—all housed within the computer case. All that’s left for you to do is connect a few cables.

To help guide you through the setup, a step-by-step printed “Quickstart” guide is included with your system. It features clear, full-color images showing exactly how to connect your Sherline CNC computer and stepper motors. (And don’t forget to plug in the parallel cable!)

This same guide is also available digitally on the Sherline Documentation CD under the filename CNCquickstart5.htm. There, you’ll find detailed photos of the system, including the back panel of the computer, to ensure each connection is made correctly.

⚠️ Important: If you’re new to computers, please follow the instructions carefully. Forcing a cable into the wrong port could damage the system.

With the provided resources and plug-and-play setup, you’ll be ready to start machining in no time.

Yes, Sherline offers CNC systems designed specifically for customers who already own a mill. These systems include a retrofit kit for either a 10″, 12″, 14″ or 18″ mill, along with:

• Three stepper motors

• A computer preloaded with drivers and control software

In essence, it’s the complete CNC system minus the mill itself.

Part numbers for retrofit systems:

• 10″/12″ mill
  Inch version: P/N 8542
  Metric version: P/N 8543
• 14″ mill
  Inch version: P/N 8022
  Metric version: P/N 8023
• 18″ mill
  Inch version: P/N 8058
  Metric version: P/N 8059

Retrofit kits are also available for Sherline lathes, allowing you to upgrade your existing equipment to full CNC capability.

Transferring G-code files from a Windows® computer to your Sherline CNC system can be done using CDs, DVDs, or more commonly today, USB flash drives.

For systems running Sherline Linux version 4.38 or later, USB support is already included:

• Simply insert your USB flash drive into the USB port.

• A USB icon will appear on the desktop.

• Double-click the icon to access the drive’s contents.

• You can then drag and drop files into the system’s “G-code” folder—just like in Windows.

• There is no need to manually “mount” or “unmount” drives in Ubuntu Linux, as was required in older versions.

Setting Up USB Flash Drive Support on Older Linux Versions (Without Native USB Support)

If you’re using an older version of Linux that does not include USB support, you’ll need to manually configure it:

⚠️ Note: This process involves editing system files. Proceed with caution. Mistakes could require a full system reinstallation.

Steps to Enable USB Flash Support:

1. Boot to the Linux desktop.

2. Log in as root:

   • Click the K-icon (bottom-left, like Windows Start Menu)

   • Choose: Logout > End session only > OK

   • Log in with:

     • Username: root

     • Password: sherline

3. Open Terminal (icon looks like a small LCD monitor)

4. Type the following commands:

   • mkdir /media/flash → Press Enter

   • mc → Press Enter twice to open Midnight Commander

5. Navigate to /etc, then:

   • Highlight and press F4 to edit the modules file

   • Add: usb-storage

   • F10 to save and exit

6. Still in /etc, edit the fstab file:

   • Press F4 and add:

     /dev/sda1 /media/flash msdos,vfat noauto,users 0 0

   • F10 to save and exit

7. Press F10 to close Midnight Commander

8. Type exit to leave the Terminal

9. Logout from root and log back in as:

   • Username: sherline

   • Password: sherline

10. On the desktop, right-click and select:
    Create New > Device > Hard Disc Device

    • Name it Flash Media

    • Under “Device,” select /dev/sda1

    • Click OK

11. Right-click the new Flash Media icon, choose Properties, and under Permissions:

    • Set Group and Others to Can Read & Write

    • Check “Is executable”

    • Click OK

In newer BDI versions, USB devices can also be managed via icons in Properties > General.

Once configured, the Flash Media device will behave like a floppy drive, using Mount and Unmount commands.

A good place to start is the regular machining FAQ page on this site. It will answer many of your basic questions about the tools and cutting metal. There is also a very informative illustrated book on machining in miniature that features Sherline tools called Tabletop Machining by Joe Martin.

One important characteristic of stepper motors is that torque decreases as speed increases. This happens because the duration of each electrical pulse shortens at higher speeds, reducing the power delivered to the motor. For this reason, it’s wise to set your feed rates approximately 20% below the system’s maximum—especially when running programs with frequent, short movements or when operating on the Z-axis, which carries more load.

• On older EMC systems, the maximum feed rate is 22 in/min (560 mm/min). We recommend staying below 18 in/min (450 mm/min) for optimal performance.

• On newer LinuxCNC systems, the maximum feed rate is 32 in/min (810 mm/min). In this case, keeping it under 25 in/min (630 mm/min) is a good practice.

Some users have enhanced Z-axis performance and reduced leadscrew wear by adding a simple counterbalance system using a rope, pulley, and weight. For a photo and description, visit the CNC Projects section on our website.

Overall, Sherline’s stepper motor system is reliable and capable of running complex programs without losing steps, when configured and operated properly.

G-Code Programming Tips:

• Begin and end each program with a percent sign (%)

• Start your program with:

  G40 G49 G21 (or G20) G90


• This cancels any lingering tool radius compensation, tool length offsets, and sets the machine to metric (G21) or inch (G20) and absolute mode (G90).

• End your program by returning the tool to its starting position

• Be aware of which G-codes are supported by EMC/LinuxCNC—some canned cycles may not be available.

By following these guidelines, you’ll improve reliability, reduce mechanical strain, and ensure smoother, more consistent CNC operations.

No problem. This program would do the job. The reason we switched to incremental was we could use the copy-and-paste edit program for each revolution of the thread.

%
g90 g40 g49 g00 x1 y0 z0
x0
g91g02 x0 y0 z-0.100 i0 j0.5 f6
g91g02 x0 y0 z-0.100 i0 j0.5 f6
g91g02 x0 y0 z-0.100 i0 j0.5 f6
g91g02 x0 y0 z-0.100 i0 j0.5 f6
g91g02 x0 y0 z-0.100 i0 j0.5 f6
g91g02 x0 y0 z-0.100 i0 j0.5 f6
g90 g00 x0.5
z0
x1 y0 z0
%

This program would cut six threads at 10 TPI.

Karl Rohlin also produced a thread milling program that includes notes explaining what each line does. He added notes to the end that explain how to do a rough and finish pass.
CLICK HERE to see the program.

The maximum feed rate for a Sherline machine is 32 in/min. However, g-code can specify feed rates of 60 in/min or even up to 240 in/min. If your program includes feed rates higher than the machine’s limit, it will automatically run at its maximum allowable speed—32 in/min—regardless of the programmed value.

In this situation, your stepper motors are likely stalling during cuts and missing steps. Stepper motors do not provide position feedback to the computer; they operate on open-loop control. When the computer commands an axis to move, it assumes the move was completed as instructed. If the motor stalls, even momentarily, and misses steps due to an excessive feed rate, the computer remains unaware—resulting in positional errors.

For a full explanation, please visit our blog post: My CNC Machine Is Missing Steps

If an axis is moving in the wrong direction, it’s likely due to incorrect settings in your .ini configuration file.

For LinuxCNC users: [CLICK HERE]

For EMC2 users:
You’ll need to edit either mill_inch_mini.ini (for inch leadscrews) or mill_mm_mini.ini (for metric leadscrews). These files can be found at:

• home/sherline/emc2/configs/Sherline (for mills)

• home/sherline/emc2/configs/Sherline-Lathe (for lathes)

To locate and open the file:

1. From the top menu bar, go to Places > Home Folder.

2. Navigate to: emc2 > configs > Sherline or Sherline-Lathe.

3. Double-click the appropriate .ini file and choose “Display” to open it.

Look for the INPUT_SCALE and OUTPUT_SCALE parameters. If an axis is jogging in the wrong direction, reverse the sign of these values:

• Change +1600 to -1600 or vice versa.

This should correct the direction of movement.

If you’re using a version of EMC earlier than 4.37, you may encounter issues caused by increased CPU usage from repeatedly running the same short program. (You can monitor CPU usage in the small window near the bottom-right corner of your screen.) While rebooting the system will resolve the issue temporarily, it can be inefficient.

Ray Henry recommends disabling the Backplot feature when running short programs multiple times, as this helps reduce CPU load.

Another effective workaround is to combine multiple copies of the short program into a single, longer file. Insert an M0 command between each copy to pause the machine. When you’re ready to continue—such as after replacing a part—simply press the [Resume] button.

Note: This issue has been resolved in EMC version 4.37 and later.

Try our Help Sheets and Instructions page for troubleshooting miscellaneous CNC problems.