MPCNC conduit rigidity -- 1/2" inside 3/4" with sleeves?

Mostly Printed CNC - MPCNC Advice
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I have some extra 1/2" EMT laying around…
I remember reading on the forum about someone who sleeved conduit inside another conduit, with some 3D printed sleeves and epoxy(JBweld), for extra rigidity.

I’m upsizing my MPCNC right now, and was planning on adding midspan supports, but also wanted to try and increase rigidity of the gantry without spending more $ on expensive conduit.

I remember reading on the forum that most recommend not going the concrete route, and that midspan supports work 4x better.

it doesn’t seem like it would take that long to sleeve and glue a conduit inside another… if the collars weren’t spaced too far apart, with enough adhesive, I would guess that it would make a noticeable difference…?

any thoughts before I go through the trouble? I was only going to do the gantry pipes

I was planning to go 36 x 48 outside dimensions, 3/4" emt, midspan supported, DW660, no plans for aluminum ever

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I would say that its unnecessary on the outer rails if you have midspan supports, and it would make things worse if you did it with the inner rails.

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I knew I had seen it somewhere and I finally found it. I dont think this is bad. It will be heavier but not that bad, and you will get better stiffness. For me it would be too much work, but if you are wanting cheap it would definitely meet that.

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Thanks, I couldnt find the link but knew I’d seen it. this seems like a very easy mod to do at just about any time, and doesn’t need much/any disassembly to install on a working MPCNC too. I’ll get the machine going again with midspan supports and add the sleeved 1/2 inch later if necessary, or when I find time to fix something that isn’t broken :wink: … probably depending on whether they open the marinas in the next few weeks or not, lol

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If you do something like this, do not do it to the gantry, it can cause more harm than good. Thats more weight that the stepper motors have to push around.

I have a 36" x 48" (outside dimensions) 24" x 36" (work area) MPCNC and I don’t have any issue with deflection (yet). In my excitement building my MPCNC I also printed mid-span supports, but I haven’t had the time (or the need) to install them yet.