Inner diameter of printed parts


I’m printing the parts to mount a 25,4mm MPCNC.

On my 3D printer, the inner diameter of printed parts, have typically 0,4mm smaller inner diamethers… The 25,4mm, have 25mm only.
This is a problem to mount?

Thanks any help!

Make sure your parts are labeled ‘J’ for the 25.4 parts

I’m assuming you’re printing the legs right now, since the rest should have space for the tube + bearings.
The Best way to know is to get a 1" tube and see how well it fits in it.

That said, I think my feet printed a little small, but I was able to force them onto the leg tubes, made for an extremely rigid fitting. the x/y holders on the legs were 25.4 and the tubing nested in them perfectly.

Hi Bradley, thanks!

Really, the part printed is the “J” (is the leg) and 25.4mm inner diameter (i measured the STL file, and have exactly 25,4mm).
This part really fit forced on the tube (because the contract on print inner diameters).

My printer was off when I printed my parts and had the same problem fitting them. Trust me, you don’t want to use those. Figure out why your printer is printing them smaller than they should be. Then print them. You’ll save yourself a lot of frustration.


On my printed parts, the outer diameter, is OK (correct measure), but inner diameter, is a 0,2mm smaller in any wall (total of 0,4mm small any diameter)… To solve this, i need use the X Y compensation on slice software, but to me, this function produce more problens, not solutions…

The inner diameters are really on 3D printers FDM, a problem. See this post about this problem:

Here other discussion about the problem:

How to solve this, any idea? On my projects i make the holes 0,4mm bigger, and fit perfect.

What slicing software are you using? I use Slic3r but I’ve read that it can be problematic with circles (this may be old info). Try another slicing software like Kisslicer perhaps and compare. Let us know.

The software was the Simplify3D.

The big question is: this inner diameter is a problem? (in the part no have tolerance, the draw have exactly 25,4mm, but the foot have the adjust to put the conduite inside. My fear is other critical parts. If the inside diameter is or not a problem.

I have designed the parts with this in mind.

They also have a tolerance built in so they are mostly interference fit, they have to be. The foot is a different part from all the rest it has the very early tolerances and is extremely tight, but should not matter because it is completely split, all materials should flex to accommodate. You should do a corner assembly or something else, the foot is not a good part to start with. If your screws and bolts fit snugly you should be fine.

Thanks vicious1!

This is a answer i need to go ahead. Thanks a lot for the project!

I send more news later! :slight_smile: