Clarification on "size"

Yea, that shouldn’t be an issue. Just don’t get snagged on the tubes! My mpcnc is conduit, and I’ve done aluminum on it. Slowly… Stainless should really stiffen it up. A lot of us route cables through the tubes, so you’ll need to make sure your wiring is long enough for the longer tubes.

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Thanks, Barry. I’d prefer to spend $8 on conduit to start with, but I’d likely kick myself later. I’m curious if there’s a size “breaking point” that gives a clearer answer like, “below this frame size, stainless doesn’t really offer any benefit, but above this size, go stainless if you can.”

Aluminum is an eventual goal, as I’m interested in making molds for silicone casting. These would be relatively small (cast part is 8x4x2"). I think I’ll try some plastics, first, though, for the molds.

I’m not sure the rigidity is the main reason SS builds are better. SS is also more accurately made and has a better longer lasting surface finish. Accuracy in the rails means more equal bearing tension and less overall slop.

The shorter and smaller you build it really really makes a difference no matter what the rails. Half any length is at least twice as rigid. In saying that less rigid just really means either slow it down or have more precise CAM, rigidity just equals ease of use.

I like the idea of a rigidity calc but I am not sure how to approach it, most of us really only fight with z axis length as the rest is usually more rigid. On top of that well executed CAM has much less strain on the system than poorly executed CAM.

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