There seems to be a lot of interest in diy CNC machines on Hackaday, and the Make Blog that has really gotten my interest in these machines piqued. I would like the ability to work on metal with a higher degree of precision than my hand affords me. I think that some of the MDF CNC plans would likely be enough to get me started making pieces of aluminum to upgrade to a more sturdy machine. I am only looking for about 24" square working surface, so it would be pretty easy to keep put away. I have been looking at these plans from CNC zone, and think that this style of Gantry is probably workable for my needs. Like everything it will need to be modified for my needs, but it is a decent touch stone for working this process.
For some reason I really struggled to get this post written. It is not for the lack of choices, but rather lack of completed affordable choices. There are lots of build logs with photos and ideas, but few that are great start to finish how to build articles with BOM's and parts schematics. The ones that are complete with Build of Materials are in Kit form and range in the $1000+ range. It seems that cognitive leap from idea to implementation requires that you extend the effort in brain exercise or monetary form. I have the left over part of a Ikea birch counter top that was bought for my wife's craft corner that I believe is sufficiently rigid for the task of being a router table and is attractive to be a long term tool. The rest of the machine will have to be aluminum and MDF. In all, I don't want to be much more than $800 in this project so we will see where that budget takes us.
Some interesting sources for information that are helping guide me at this point.
This site looks like it will grow over time, at the time of writing the site is updated several times a week and has some good thoughts on design, and talks about options rather than focusing on a single design and build. I think it could be a great source ones the links get laid out properly (I get enough page cannot be found errors to make me think it is a work in progress)
This site sells router plans and seems like a good resource for people that are interested in building, but not engineering their solution.
Excellent source for drive system and step motors.
A CNC kit site that I like, they have great looking designs that are pricey.