25.4mm OD Conduit?

Mostly Printed CNC - MPCNC Advice
1

Friend of mine is building the new Primo and went to buy conduit and it doesn’t fit at all. Is the 25.4 Primo not made to use conduit?

2

I mistakenly assumed that 1" conduit was actually 1" outer diameter.
Now i’m searching for steel tubing locally!

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3

No, the 23.5 mm set is made to fit three quarter inch electrical conduit I believe. The 25.4 mm printed parts fit one inch outer diameter stainless steel tube or DOM

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4

Running into the same issues finding a supplier. The quote 1" tubing at the box store is slightly bigger than 1". So I’m looking at going from something like $10.84 for 12 feet of tubing, to like $28+, for 3 feet.

Found something that might work at Tractor Supply for $12.99 / 36", but I haven’t been there yet to check it out. - national-hardware-4068bc-1-in-x-36-in-round-tube-plain-steel-red-16-gauge.

Looking at - Amazon item: B00NQWL71U , but it seems too good to be true - $62 for a 10 pack of 4 foot tubing, and Prime delivery. It’s made for displays, like clothes racks, so probably not as strong.?

Anyone find anything better?

5

Hi Mark. Welcome to the forum. I’m not an expert on tubing, but in following the forum for the last half a year, I’ve not seen an MPCNC built with the kind of tubing you are listing in your post. I believe this tubing is chromed and primarily used for things like railings. I would be concerned that 1) the OD is not accurate enough, 2) the OD is not consistent enough, and 3) the metal is not treated to get the stiffness necessary for good results using the MPCNC. Just guesswork on my part.

The three US choices I see on the forum are:

  1. 3/4" galvanized electrical conduit from a big box hardware store. This conduit uses the 23.5mm 3D printed parts. It is cheap, relatively stiff, but it often needs to be sanded to get the machine to run smoothly.
  2. 1" SS tubing (not pipe). Significantly more expensive. Resists rust. Stiffer than the conduit.
  3. 1" DOM tubing. The stiffest choice. Will rust if not treated with a paste wax.

I used conduit for my Burly build. I upgraded to SS for my Primo build.

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I think I recall someone buying the T/S tubing for their primo build. From reading the description it looks like it would work fine. I don’t think its actually “DOM” tubing but I have seen others in the forum use non DOM tubing with success.

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