DIY CNC Routers - my tips

[MadPickinSkills]

I just thought I'd give my $.02 about building a cnc router. Just a few tips. Depending on the level of accuracy and the amount of rigidity you want, you need to consider what components go into the machine. IMO, it's always best to use aluminum parts for it's construction, whether it be extruded "erector set" t-slot parts or square aluminum tubing. The aluminum parts are much more rigid than sheet metal, plywood, or mdf.
The linear motion systems should ALWAYS be supported linear shafts, not unsupported. Whether they are round shafts or THK style linear slides. It's been my experience that unsupported shafts will not be rigid enough unless they only have to travel a short distance.
Pulley systems are not the best way to go for movement. Ballscrews are not that expensive and are much more accurate.
I've been operating and programming CNC routers since 1995. I've been around many different styles.
The materials I've suggested may be more expensive that some of the others, but in the long run, you will be much happier with the finished product.

[royzturbo]

Hello, I'm new to this forum and I'm building my first CNC machine. So far I've acquired THK linear rails at 25 mm thickness with HSR bearings, Kuroda ground ballscrews, 10mm pitch for x and y and 5 mm for z. I am currently looking to acquire some extruded aluminum for the chassis. Is there an advantage to using T slot over square aluminum tube when it comes to rigidity. The total travel of my machine will be approximately 18 inches in either direction.