Deflection in precision rod rails

[Smiler]

:rofl:

Pretty bendy stuff but average joe probably wouldn't be bothered (or know to be)

Quite. I think it depends on the intended purpose of the machine too. For instance, I'm not going to be bothered about even .25mm deflection when I'm routing a house sign. On the otherhand, I would like good precision if I'm milling a mold for a modelling project. I'd like to see the results of the same experiment done with the ends properly clamped and bolted down to a firmer surface than MDF. I bet a clamped rail bolted down to a steel base would fare better.

Since I'm running 1m unsupported 20mm rails on my machine I may well do just that.