Hello Wizard,

thank you for your input, it makes perfect sense.

This is a personal project, except that the objective is skewed toward learning the making of a cnc rather than that of parts so, to a certain extent, I'm actually interested in "making mistakes" so that I can know first hand the problems of some solutions and the benefits of others beyond purely hearing it from people. One example is the aforementioned wear, which I've heard a lot about, but only in one or two post I've actually seen people talking about details, saying for example that 1/8 aluminum rails become unusable after about a year of light use. Given that this machine will be far from operating 24x7 then that may be perfectly fine. Of course I'm trying to avoid expensive or really stupid mistakes.

When you say a round rail, do you mean SBR or even a round rail with a pipe? and yes, economics is definitely a factor, especially given the context of expecting ongoing changes as I test different designs (this is my very first one) and I most definitely can't afford SBRs now.

thanks again for your insights.