Experience/Opinions re tubing choices

Mostly Printed CNC - MPCNC Advice
1

I’m in Australia where our hardware choices are bit more limited than they seem to be in the US. for instance, if you go to our ‘big box’ hardware store (Bunnings) and look for electrical conduit all you will find is PVC. Metal is available, but only from trade suppliers or the manufacturers (mostly in the larger cities). For metal pipe and tubing there are more options, but again mostly in the major centres (which I’m not near), and/or at much higher prices. What is costing about US$8-10 for conduit is about AUD$42-$45 for 25.4mm 1.2mm thick galvanised steel tubing from Bunnings. Stainless would have to ordered from elsewhere and would be AUD200-300 plus freight.

So I had a bit of browse around in Bunning looking for alternatives and found “25mm” chromed steel “wardrobe rails” and “curtain rods” - two different products from different manufacturers - ie metal tubes. the size is in quotes as I haven’t confirmed whether they are actually 25mm or really 1 inch ie 25.4mm. They also provide no info about the wall thickness, but I think they are less than 1.2mm probably .9-1.0mm.

So to the questions :slight_smile:

  1. Stiffness is largely determined by the diameter, and given that many of these machines have been built with 23.5mm conduit, I am assuming that the difference between 25mm and 25.4mm (if there is a difference) won't be important. Correct?
  2. Is the wall thickness whether .9, 1.0 or 1.2mm sufficient for the desired stiffness?
  3. Is it enough to deal with point pressure?
  4. I'm interested in the chrome as it should be better wearing and smoother than the galvanised finish. Is this valid?
  5. If so, enough benefits to warrant 20-30% higher cost eg around AUD7/meter vs AUD5?
Thanks :)

Chris

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Hi Chris. There have been quite a few threads about finding the correct tubing in Australia, unfortunately I didn’t pay much attention. You might want to search by your city or closest major city here in the forums. You are on the right track with your questions though.

1-Correct, whichever one you can find won’t by vastly different. Bring in some calipers those closet rods are rigid as heck and if they fit…win!

2-I believe 1.2 is about average for what we use, a little thicker is nice, but solid is overkill.

3-same as above.

4-I would guess it will come off at least wear in 3 little strips, so same with or without. 5-Nah.

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