Pipe

Hi

I got my 1 inch od pipe source and it’s just slightly larger. A little less than .04 inches. My print is at inch. I know it will be tight but any ideas on how to correct that? Was thinking of maybe sanding it slightly with a bevel or perhaps freezing the pipe

Get the correct steel.

Sanding that much down will leave an uneven surface, and will take far more time than you think.

Freezing it might put it into spec… Until it warms up. If you’re planning on building/using the machine in a walk-in freezer maybe, but it seems like a bad ideal all-around. For one thing, the bearings aren’t really rated for really low temperatures, and the plastic will very likely get brittle.

So the solution is to get the correct 1" OD steel

Wall thickness doesn’t matter, so long as you get tube not pipe. Tube is measure by outside diameter, so 1" OD diameter with 0.065" wall (Pretty typical and common) will be the same as 0.100 or 0.125" wall.for what we need (Though the nut traps for the Z axis might get difficult to fit.)

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0.04 inch is about 1mm. That is a lot.

As a point of reference, there are two designs for 25 mm and 25.4 mm. The difference is bad enough that stuffing 25.4 mm tube in a 25 mm design is not acceptable.

So trying to fit 26.4 mm tube in a 25.4 mm design is a bad starting place. Sanding off that much metal (and doing so evenly) is not going to be worth it, compared to getting proper tubes.

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The temperature coefficient of steel is let’s say 15e-6 per degree C, so that’s 0.15 percent size change for 100 degrees C temperature change.

If you want a 4 percent size change, you need to cool by 2600 degrees C.

It will be very hard to cool more than a few hundred degrees C. :wink:

Plus what @SupraGuy said.

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Which is the correct steel. I went to Home Depot and measured it and it’s 1 in od. The conduit they had wasn’t anywhere close. I will see if i can take pics tomorrow maybe my print settings are incorrect

This is from a little more than a year ago:

I have looked at “one inch” pipe at HD and wished it would work, but it really needs to be 25.4 mm. I’m sorry.

Any idea on where I would find something? I have only printed 4 pieces so if anyone has scaled it for that od I could reprint. @vicious1 any ideas? I wish I would I have brought some calipers cause it fit with the threading at the store and nothing in the quote en quote conduit was even close

The “3/4 inch” conduit is the only stuff that works at home depot. It fits the C version.

Otherwise, find a steel supplier locally that has 1" tubing (tubing is measured by OD because it is structural. Pipe and conduit are measured by ID because their job is to hold stuff inside). 1" tubing fits the J version.

Those statements do not agree.

Pipe is always measured by internal diameter. Tube is measured by external.

1" pipe will always be too large. The conduit that Ryan designs for is 3/4" (19.05mm) internal diameter, and that ends up being 23.5mm OD, though it is certainly conceivable that some 3/4" conduit might end up being wrong, while still being 3/4" conduit, as it happens it’s consistent enough to remain usable.

Look for somewhere that sells structural steel, and ask for 1" tube. You will get steel tube that is 25.4mm, which will work.

This conduit?
https://www.homedepot.com/p/3-4-in-x-10-ft-Electric-Metallic-Tube-EMT-Conduit-853429/100400406?MERCH=REC--pip_alternatives--100400409--100400406--N&

I think I found a pipe supplier locally but this would be a lot cheaper. Does the strength get weakened?

I hope you mean tubing :slight_smile:

Yes. I’m not sure how HD decides which manufacturer goes where, but this is a commodity part and they are all pretty consistent.

This conduit is not as rigid at 1.00" steel tubing. But it is a lot cheaper. I can tell you that it still works really well. If you are planning on milling harder materials (like aluminum+) or plan on making it larger, then you will want the tubing.

The two common kinds of steel tubing are stainless and DOM. Pay attention to the wall thickness too.

https://docs.v1engineering.com/mpcnc/PParts/#printed-parts-sizes

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