Epoxy me this!

So i had an idea, Im going to be using SS tubing for my build. I was wondering tho if i filled the tube with epoxy to make it stiffer if that would work? What is your guys take on the idea

Not enough to make up for the added moving mass.

I would only do it on the outside frame. I’m also printing those parts out of abs at 100% infill

If you search the forum, you will find a number of topics on filling the tubing with various substances. Like:

And I’m sure there are many more. They are worth reading, but generally they are long on theory and short on any real-world testing. And I wouldn’t bet against Ryan’s assessments about added mass. The one filling idea that seemed to me to potentially have merit is Dan’s foam filled tubing, and only for dampening, not to add rigidity.

I’m also printing those parts out of abs at 100% infill

ABS is less stiff than PLA. I don’t know if printing it at 100% infill rather than the 45%+ Ryan suggests makes up for using a less rigid material. I’m sure the ABS pieces will work, I’m just not sure you getting anything in return. Note that carbon fiber ABS is somewhat more rigid than PLA, so that might be something to consider if you haven’t already printed the parts. Note that if you are only looking at stiffening the outside rails, corner supports and mid-span supports may be a better investment, though you might just run your machine for a period of time to see if you have any problems to solve.


For what it’s worth, I did test the expanding foam.

While it did decrease load deflection, I didn’t end up doing it on the machine, because it interfered with running wire harnesses through them. It seems to be mostly the gantry rails that would have benefitted most, and those are the ones where I needed to run wires.