Black pipe from Home Depot

Looking to upgrade from burly to primo. With my burly I used conduit but now I want to use stainless steel. I got a quote for the pipes and it was $200 for two 10ft pieces. I was wondering if anyone has used black pipe from Home Depot as an alternative. The ones used for gas lines.

Try Speedy metals also the recommended alternative to the stainless is DOM (drawn over mandible) steel you can also get both from grainger

Pipe and tubing are measured differently. Pipe/conduit size is driven by the inside diameter. Tubing is measured using the outside diameter. So you need to either use 3/4" conduit or 1" tubing of some sort…stainless steel, DOM, etc. For example, 3/4" black pipe is 26.9mm OD and 1" black pipe is 33.4mm OD. You need an outside diameter 25.4mm for the 3D printed parts to fit.

And the price of $200 for 20ft of 1" SS seems high to me.

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Drop the stainless part of the tubing quote.

I asked about dom he said it was more expensive. There is a grainger near me I’ll have to see if they have it in stock

Thanks that’s answers that question and I felt like the price was high

I just ordered and received 4 pieces of 3’ 8" 1" OD polished stainless from Metals Depot for $106.75 including shipping and taxes. They ship anywhere in the US from their omline website. $200 is way to expensive. You need to stay with lengths under 6’ to get reasonable shipping.

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Not sure where you are but I payed just under $5/ft cdn for my ss tubes. If you can avoid shipping by buying local you should be able to save a fair bit. Many metal suppliers also have drops bins with lengths under 4ft where they sell by weight. If you are patient you can get really lucky that way too.

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I would love to use the black pipe from home depot as it appears much stiffer but the problem is the outside diameter is 20.93mm or 0.824in … so we would need a new set of drawing.

Design decisions are full of tradeoffs. At a glance black pipe might seem to be better, but that perceived extra stiffness comes with extra weight. That weight must be moved around by the steppers, so you will need to slow the acceleration and probably max speed to compensate. And that weight must be supported, so there may be sag in longer pipe runs. Also it is unclear that the tubing is the weak point in terms of stiffness since significant portion of the machine are made of plastic. Ryan made the decision to support three sizes of tubing. If you want another size you will need to reauthor the parts. If you are competent with a CAD package, this is not hard, but time consuming. Several people on the forum have indicated their plan was to reauthor the part for another size tubing. The only success reported back to the forum was for 1" conduit (which has an O.D. of approx. 1.16").

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Good points Robert. The reason why I want a stiffer frame is to get a bit bigger working area and avoid having to print the feet and corners, as shown in this picture: 2021-04-19_18-16 (they sell steel fittings so that you could screw them to the pipes and then screw them to the table and Home Depot thread for free any custom length of these pipes)

That’s a lot of modification, almost every part would need to be changed. And not just for the size but also because you have those x y pipes in the same z plane. That would cause interference between the x and y gantry bars. If you overcame that I feel it would still have a huge negative impact on your ability to tram the machine and on the cores ability to withstand horizontal forces.

I strongly recommend building the machine stock first, then decide if it needs to be changed for your uses. I have seen mpcnc as big as 24" X 36"… if you want bigger than that build a lowrider :wink:

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There’s some folksy saying for this. But you’re avoiding printing a few easy parts at the expense of having to do a full redesign. You won’t be saving time or money, and where will you attach the belts?

These are solvable problems. And if you came here to invent a new machine, more power to you. But IMO, this idea isn’t generally “worth” pursuing.

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