Sherline CNC systems that include a computer come with Linux and EMC already installed. This eliminates any potential installation headaches for the user. The 8760 driver box includes Linux and EMC on a CD for you to install on your own computer should you choose to do so. There are other operating systems like DOS and Windows® that are also used for CNC applications. Windows is probably the most prevalent operating system used in the world today, but it is not ideal for running CNC. Linux is in many ways operationally better suited for running CNC, but there are some drawbacks if you are going to attempt to install it yourself from the disk provided. Here are some things, both positive and negative for you to consider regarding Linux:
- (+) Unlike DOS or Windows®, Linux and the highly capable EMC control software Sherline uses is “open source” software and is provided at no charge. It is as capable as software costing many hundreds or even thousands of dollars. Even though we paid many thousands of dollars to developers to have it customized to our application, we charge nothing for it, which keeps our system cost low.
- (+) Once properly installed, the Linux interface looks and works much like Windows, so it is not difficult to use.
- (+) Because Windows uses multitasking to run several operations at a time, it can cause pauses in the stream of CNC data, which can lead to interruptions in the cut. In order to overcome this, some companies provide a post-processor (signal generator) that buffers the data, but this adds even more to the system cost. Early versions of Linux did not support multitasking, so they were very smooth running compared to Windows at that time. Now, with the Ubuntu version of Linux multitasking is supported. The way Linux handles data requires no buffering to offer smooth performance when running CNC. Operationally this makes it an excellent choice for CNC. Once running, it is also extremely stable and crash free. Newer versions of Windows seem to run fast enough that this may no longer be an issue, but when the decision was originally made to choose Linux over Windows the choice was an easy one.
- (–) Because it is not sold for profit, keeping it up to date is done by a group of talented and devoted users, but the system tends to lag somewhat behind the rapid development of new hardware. This can lead to problems where very new components or old components from small manufacturers are not supported. There is no guarantee Linux will install on your computer, particularly if it is either very new or has older components from a small company. Drivers are written for these components on a voluntary basis by the group of Linux users who support the operating system. New components may not yet be accommodated, and low-volume components do not generate sufficient demand for the group to write drivers for them. The new Ubuntu version of Linux that Sherline switched to in September, 2009 is just as easy to install than the older Debian version and supports a larger variety of hardware, but we still cannot guarantee the installation will be successful on your particular machine. This is why we offer a system complete with computer and software already installed for those who simply want to take it out of the box, plug it in and start working without worrying about installation or compatibility issues.
- To compare actually using Linux vs. using Windows, CLICK HERE. They are probably more similar than you think.
Technical Assistance and Other Options
Technical help on EMC at www.linuxcnc.org. Questions about the physical setup or running of the machine and basic questions about Linux and EMC2 can be answered by Sherline at (760) 727-5857 during business hours M-F, 8-5 (Pacific).
If you are unsure if you have the proper components and experience to try a Linux installation, your options are to purchase a full Sherline CNC system including a properly configured computer with Linux and EMC2 already installed or to buy a Windows-based system. Most likely you could still use the 8760 driver box even with other software. Keep in mind also that Linux may install easily on your computer. If it doesn’t, the cost for a new video card or component needed to make your system compatible with Linux may be very minor compared to the other options if you are willing to do a little research and experimentation. The cost of a new Windows-based system may be much higher because you will be paying for the operating system, the software and possibly a signal generator of some sort to buffer the signal.
Installing Linux yourself
A lot of people say, “I already have a computer, why do I need another one?” Because EMC runs on Linux, it will not work on your Windows computer. If you install Linux, it will completely overwrite Windows and you will lose all data on your computer. If you have a computer on hand that you are willing to dedicate to Linux and EMC, it is possible to buy just a CNC-ready machine, some stepper motors and an 8760 driver box and power supply that includes the Linux/EMC software on CD. However, Sherline offers NO GUARANTEE that Linux will install on your particular computer. If you are unsure of your ability to install Linux, we highly recommend that you consider purchasing the complete system including Sherline’s computer with the operating system and software already installed. We have invested a lot of time and effort to make sure we have the right combination of components that work with the software we supply, and purchasing the entire system allows you to get to work right away learning and using CNC without the additional hassle of software installation and component compatibility problems. The new Ubuntu version of Linux offered as of September, 2009 is just as easy to install and supports a greater range of hardware than the older Debian version used before that time. EMC is used essentially the same between the two versions, but the operating interface of Ubuntu Linux will be more familiar to Windows users. The primary advantage of EMC2 over the older EMC is that EMC2 now includes a lather program as well as a mill program. With all that said, the choice of “plug and play” or “do-it-yourself” is up to you.
For the Redhat version we used to recommend a minimum of 500 Mhz clock speed for the processor. The Debian version requires a little faster computer to keep up, so we now recommend at least an 800 Mhz clock speed if you use your own computer. The Ubuntu version will work at that speed as well. The computers Sherline uses are faster than this, so you need not worry about clock speed. At least 512 Mb of RAM will also be required for the newer versions.
Here are some additional links to sources to help you with Linux installation and use:
Sherline Computer Specifications for Linux Systems
Here are the components in the Linux computer we supply with our systems. If you are purchasing a computer you intend to install Linux on, use this as a guideline:
- Processor Speed: 1.2 GHz or faster
- RAM: 512 MB
- Hard Drive: 80 GB
- Internal drive: DVD-RW
- External drive: 1 GB USB Flash drive
- Current: Internal switches are set to 110VAC but can be reset for operation with 230 VAC
- Installed software: Ubuntu* Linux-based OS with EMC2 4-axis CNC software.
*Note: Prior to January, 2005, Redhat version 2.xx was installed. From January, 2005 to September, 2009, Debian version 4.xx was installed. Starting in October, 2009 Ubuntu version was installed. Our 6.0 version of Ubuntu with “Lucid” build installed starting February, 2010.