Started planning...couple questions

[~TM~]

Hey guys, I've been visiting this site for awhile and have started planning my own CNC. First off thanks to everyone who comments and shares their wisdom/knowledge with all of us just beginning this obsession. The wealth of knowledge is a little overwhelming but very appreciated.
Ok now down to business. I'm planning on constructing the bed with a usable area of about 24" x 36". I've been saving some 30mm linear bearings (open style) for the y-axis and a few 16mm bushings/bearings for the z. I wanted to use supported rail but don't want to spend $$$ for the manufacturers rails. I was thinking about some drill rod, or stainless steel shaft. It needs to be tight tolerances...any ideas/suggestions? Know any good websites to order from?
Also should i think about using thick wall tubing instead and make some supported rails myself, i don't have a milling machine or anything, I'm a furniture maker so it needs to be fairly painless for me.
Thanks for any comments, I'm excited to finally start seriously planning.

[BobF]

Look at Joes kit in the JoesCNC subforum.

[teamtexas]

You may want to check out www.buildyouridea.com. He made some supports for rails with a lost foam casting process. I followed his work to design my linear bearings, only wish I would have stuck with the supported shafts. My cnc router is almost done and I'm already planning a way to change the unsupported x axis.

[~TM~]

bobf,
I've definitely gone through joes build, it's been awhile but I think he still uses drill rod as the rail system and i think he orders it from Enco. Problem is that they don't sell much drill rod in metric, particularly 30mm. It is a good idea, I just need some leads on where to get some the size i need. I tried searching the internet for over 2 days with no luck. Metric is rough to find that large.

Texas,
I have also seen that build as well, great work on his part. That was my other idea, using tubing instead of rod, that way i could make a T-supported railing that was easier to attach, less expensive but offered more rigidity than an unsupported 36" rail.
Has anyone tried using found rod/tubing with THK, NB, etc high precision linear bearings? Will it work or will i be disappointed with a sloppy/too tight fit from the tolerances?
Thanks for the replies

[teamtexas]

You may try McmasterCarr for the metric rods, They are a little pricey but they seem to have everything.

[BobF]

Praire Dogn,
Look at post 92 in this thread for an alternative to round tails.
Alternative to round pipe.