Printed model doesn't have the exact dimensions as designed (diameter of cylinder).

[drobble 0]

Hi folks,

I'm currently dealing with a little problem.

When I'm printing a model with a cylinder created in FreeCAD (v0.21.0), let's say with a diameter of 19mm, sliced in Cura 5.4.0 and then printed on my Ender-3 with 0.6mm nozzle, the cylinder turns out has a diameter larger than the 19mm designed. There is no scaling involved in the process between the design and the print.

I'm trying to figure out in which step the alteration happens.

Hopefully someone can point me where I have to make some modification in the process.

TIA

PS. I posted a similar entry on the Creality FB group but I think this forum is the better suited one since I think something happening during the slicing.

PPS. I'm using Cura 5.4 since the versions 5.5 - 5.7 (slicing) don't work in my case.

[Slashee_the_Cow 620]

Remember that the diameter will always be a multiple of your line width ± minimum wall line width, but it's best to not rely on the minimum line width and make it a multiple of your line width to keep flow consistent.

 

There's also the setting Experimental > Slicing Tolerance which controls how it rounds numbers when they don't match:

• Middle rounds up or down to the nearest number. Means your print will be roughly the same size as the model.
• Exclusive rounds down. The print will be at most as big as your model, which means it may cut off a wall or something if it can't make it fit.
• Inclusive rounds up. The print will be at least as big as your model, even if it means adding another 0.4mm wall when there's only 0.1mm which wouldn't be printed without that wall.

[drobble 0]

Could it also be that the nozzle diameter has an impact on the result of the print?

I made the observation when using a nozzle with 0.6mm diam.

Can the line width be less then than nozzle diameter?
 

Otherwise, I appreciated your comment about this subject.

Thanks.

[Slashee_the_Cow 620]

11 hours ago, drobble said:

Can the line width be less then than nozzle diameter?

The general guideline for line width is 60-150% of the nozzle diameter, so on a 0.6mm nozzle you could probably go down to 0.36mm (or up to 0.9mm if you wanted to).