Is 25mm x 3mm Stainless Overkill/Too Heavy

Mostly Printed CNC - MPCNC Advice
1

Hi all,

Usual newbie builder question, I have some 25 (o.d) x 3mm stainless 304 pipe I was hoping to use in the place of conduit, price is reasonable, plus I already have some and its insanely rigid, but as you can imagine it is pretty heavy.

Like most I’m chasing rigidity and assume more thicker, more better, but obviously there is there a point where weight will cause more problems than it will solve, i.e straining x/y steppers, stress printed parts, but I’m wondering if this is that point?

I’m not looking for a large machine, equal to the standard footprint or most probably smaller, for reference a 300mm section is approx 470g.

Or would it sensible to mix pipe thicknesses, sturdy perimeter, lighter x/y and lightest possible z?

Any advice appreciated, hopefully it will give me one less aspect to obsess over until the many hours of printing are over.

 

2

I would think for the perimeter anything would do, you could probably use solid rod if you wanted. But I’d try to minimize the weight that’s moving.

3

I think Dui is using solid rods for his perimeter rails.

4

None of that is or would be the issue, the heavier you are the lower your accelerations have to be.

As with most of us you are kinda overthinking it and worried about a problem you don’t have. As is at the sizes you are talking EMT conduit works perfectly, Stainless is even a bit of a waste, extra thick stainless is even more so and starts to hinder. It is designed as a complete system, balanced.

5

Fair enough, I guess deep down I kind of knew that might be the case , just optimistically hoping it might be suitable as I have almost 3/4 builds worth already just sitting there, plenty enough to do the perimeter and legs so I won’t waste money getting more and go with something thinner wall for x/y/z.

I get what you are saying, but I might stick with stainless , if not for rigidity and taking cost out of the equation, would the (generally) better surface finish, dimensional accuracy, corrosion resistance and (slightly) better hardness not be a bonus over conduit long term, I know I’m going to be passing this thing down to my grandkids, but hopefully you can see where I’m coming from?

1.5mm SS looks to be roughly equal per kg/mtr to our (UK) 25mm class 4 conduit which looks to be around 25-30% heavier than US 3/4" EMT

6

Heck yeah, I have a small stainless build for this very reason. I know deep down it isn’t helping anything but it IS better…