Here is list of links which go to free sets of CNC plans. Although some of these plans can easily be found just by a quick Google search, others are much more difficult to locate.
It can take awhile to fully absorb the information on some of these sites, so it is best to view them multiple times before you actually decide on which plans you will use to build your CNC.
Please note that I haven’t personally built or used all of the CNC machines listed on this page, so I can’t, and won’t, guarantee that they will all work well. They are free though, so there’s nothing to lose just by taking a quick glance.
Also, if you are interested in making your own CNC, you should check out the CNC Machine Build Logs page. You will no doubt see some of the same CNC machines that are on this page there. What makes the CNCs featured here special though is that they have considerably more information available to those individuals who are interested in building their own. For that reason, they deserve their own page.
Here is a very well documented open source CNC design. The DIYLILCNC has its own dedicated site along with all the information you could possibly need to build your own.
CNC Plans and Kit
This site has nice set of plans for a CNC made from what looks like aluminum. You can either make the parts more or less from scratch, or you can buy one of the kits which has the parts ready made for you.
From one of the videos on the site, this machine appears to be capable of milling aluminum. Very cool!
Desktop Sized 3-Axis CNC
This link goes to a set a plans for a small CNC built from pipes. Although it is small in size, it is possibly the cheapest CNC you could hope to build. It is also perfect for simple experiments and first learning to use a CNC.
Here is another link which goes to a CNC that is similar to the one at the above link http://lirtex.com/index.php/cnc. This CNC isn’t exactly the same, and there aren’t any plans for it, but it’s similar enough that it might be useful to take a look at it and learn something from the pictures.
You’ve probably already seen this one before, but I figured I would add it anyway just to make the list complete. I wouldn’t really recommend building this design without doing some modifications to it first as there are a few things that could be improved. Overall though, you might find these plans to be useful. If nothing else, you might use it as a starting point for your own personal design.
Build Your CNC
This site has a CNC which is meant to be easily built using simple shop tools. I built this one myself once and was able to do so without much trouble. There are several videos which document each step of the building process.
UPDATE: The author of this site has added the G-code files (.NC) for one of his newer CNC designs. The exact link is http://buildyourcnc.com/cnckit2.aspx (5/31/09)
Joe’s CNC 2006
The CNC shown above is mine and is based off of the Joe’s CNC 2006 design.
This CNC is designed to be cut out with another CNC, so it might not be the first one you build, but you could make it your second.
UPDATE: The plans that I used to make this CNC seem to have either been moved or just taken down.
Here are a couple of other links too which might be useful for building Joe’s CNC.
This link goes to a set of plans for a really big CNC machine known as the MechMate. This CNC is for the CNCist with an especially large shop. Be prepared to get out your wallet for this one. Note: You must register to view the plans.
3-Axis CNC Plans
These plans have been around for awhile, so you’ve probably seen them before. They seem to have a great deal of detail, which is always nice. This is one of the better documented sets of plans out there.
Here is a site which features free CNC plans. There only seems to be two available at the time of this writing, but there might be more later. One set of plans is for Joe’s CNC 2006 which has already been covered on this page. The other one is the JGRO CNC design which has not been covered.
This link to CNC zone goes to a thread with several CNC designs. Some have already been covered on this page but there are a few new sets there. You will need to register to view them, but it’s free so there isn’t any reason not to.