Before starting, you should have a computer that is worthy and capable of running Ubuntu 8.04 and EMC2. The computer that I’ve built for this is antiquated compared to today’s technology. It’s a Pentium III 667MHz with a 20 gig hard drive and 384MB RAM. Your cell phone probably has a higher computing power than this, but according to the EMC Latency Test the computer is perfect. If you aren’t into building computers just to find that they don’t work with EMC, Lumenlab.com sells a computer that is proven to work because it’s been hacked by them. If you buy theirs, you can skip this whole article.
It is a good idea to join some of these forums or places like them to get help in the event you experience a problem that I can’t explain: ubuntuforums.org, linuxcnc.org, cnczone.com, lumenlab.com, etc. If it isn’t explained here, chances are you’ll need to ask the question in a global forum and hope someone else knows a fix.
Follow these steps with your computer:
- On a working computer with a CD-R drive, download Ubuntu 8.04. I chose to use an ALT-INSTALL without EMC2 because I have better luck with them on these old computers. I will install EMC2 later. Ubuntu 8.04.4 LTS (Hardy Heron)
- Burn the image to a blank CD.
- Insert the Ubuntu 8.04 install CD into the target computer.
- Power up the computer, and be sure that the CD drive is the first boot device in your startup routine.
- Install Ubuntu on the computer by following the prompts. (Support on how to do this is beyond the scope of this article. If problems are encountered that are not described here, visit an Ubuntu forum and look for assistance.)
- Be sure that you partition your hard drive correctly, using the whole disk guided method should be sufficient.
- While partitioning, erase the hard drive!!! Not doing this has caused me many hours of head scratching when the installer hangs up at the very end.
- After erasing your hard drive, format it.
- After the installation is complete, remove the CD from the drive and restart your computer into Ubuntu.
- Set the repository by going to System->Software Sources
- In the Third-Party tab, uncheck the CD box.
- Next, update your system. Open the terminal and type “sudo apt-get update” without the quotes. Hit enter and follow any prompts. Then type in “sudo apt-get upgrade” without the quotes. Hit enter and follow the prompts. Your Ubuntu should be up to date.
- Go to linuxCNC.com and download the EMC2 install file for Hardy. Linux CNC.org – Installing EMC2Follow the instruction on their page to install EMC2.
- This program should open a terminal window and install. If it does not install or the window abruptly closes, open a terminal and type in “cd \Desktop” or whatever path you downloaded the file to then hit enter. Type “ls” and hit enter. Then type something like this “./install-emc2.sh” and hit enter. Just follow the prompts.
- If you have a broken package, go to System-> Administration-> Synaptic Package Manager. Click Edit-> Fix Broken Packages. You may have to update your system like in the third bullet of step 6 and then come back to install EMC2.
- Once EMC2 has installed, restart your computer. While it restarts, hit ESC as GRUB loads and be sure to select the RTAI kernel. EMC2 will not run in any other kernel.
- Once UIbuntu has started, go to Applications-> CNC-> Latency Test
- This is your first step towards being a CNC operator. This will determine your computer’s eligibility to run EMC2 and control your CNC router.
- While the Latency Test runs, it is recommended that you abuse your computer. Not physically as to actually damage your computer, but “softwarically.” Run the internet, edit some pictures, play some games, all at once. Wiggle the windows around. Maximize and minimize. Then watch the Jitter.
- Anything between 15 and 25uS should be good for CNC routines. Reading through the LinuxCNC.org site may help guide you to ways to tune your computer to perform better in the Latency department.
- Video, network, and sound cards can all interfere with the effectiveness of your computer.
In the end, this last screen shot is what you want to see. My computer’s latency is between 18 and 19uS. You can ignore the terminal. I was just checking to see how well my computer managed the little bit of memory that it has. Yay, it works.!
[Edit: 3-8-2011 - fixed broken link to Ubuntu resources.]