re: How to align roller stands?

Thanks for all the replies guys! In general I was leaning towards the version that has 3 rows on ball bearings, no rollers, for the skewed direction reasons mentioned. As for why that seems advantageous over a single roll of ball bearings, multiple spaced rows seems like it would hold up a board better than just a single row creating a narrow fulcrum.

A part of me had wanted to think “don’t overthink this” another part of me likes perfection and felt a compulsion to apply the same bed accuracy logic to roller stands too. Sounds like I should still do what I can to incorporate precision, but I’m not crazy to think that it’s too far fetched to achieve repeat perfection on that matter, and instead likely makes more sense to just do the best I can and leave it at that.

I think to date, the longest board I’ve needed for a project was maybe 10-12’ long, and that was a project that was more than acceptable to use non-milled lumber for. It’s my hope that the roller stands could afford me a bit more capability to handle longer boards, but also that ideally I never find myself planning a project that makes me think “crud, if only I had a 72” long joiner bed”