I recently found these stainless steel tubes, from an old milk factory, so I thought I might as well make an MPCNC now that I have the rails, and a spare router. But since the tubes are 304 SS they only have half the carbon content of normal 301 SS. And I wondered whether someone has tried making an mpcnc with 304 SS, and seen if it is too wobbely(unrigid??) , before I print the parts.
You should be able to support both ends and give it a push to see how flexible it is. I’m willing to bet it’s as rigid as you’ll ever need. Depending on the span of course.
The Carbon content of the steel doesn’t materially effect its stiffness. What’s more, the Modulus of Elasticity (measure of stiffness) of 304 is actually slightly higher than 301 so it is a better choice for this application than 301 (even if it is
304 does ha a lower tensile strength (90ksi vs 120ksi), but that is a measure of how much force it can take before it fails and isn’t the relevant metric here.
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