Ender 3 Pro - Hole Problem

[dolby]

Hello

I have a Ender 3 Pro and i've created a model in Tinkercad. One Part of this model is a ring (see attachment). After printing this ring i found out, that the inner diameter of the hole is to small compared to the outer diameter of a ring. The outer diameter is good. I have calibrated the printer: stepper motors (X, Y, Z, extruder), bed leveling, checking belts and also the first layer. It has not changed much.

Usualy i slice with Cura. So i made a fresh Cura installation on an separate computer with only changing the neccecary things to print it and i also have done it with the Prusa Slicer.
I also tested it with 2 different Filaments.

The results are the following:

Slicer	Filament	Inner diameter to small
Cura with my settings	Extrudr NX2 black	0.54 mm
Cura with my setings	3DJake EcoPLA red	0.70 mm
Cura new installed	Extruds NX2 black	0.53 mm
Cura new installed	3DJake EcoPLA red	0.76 mm
Prusa new installed	Extrudr NX2 black	0.28 mm
Prusa new installed	3DJake EcoPLA red	0.31 mm

I know that measuring such small things is quite difficult, but it shows that the problem is smaller on the Prusha slicer, but still existing.

I dont wand to change the model and reducing the inner diameter, this will not help if i print a "ready made" model.

I was reading through the internet, but have not found anything that helped. Your help is very welcome.

[Ender5r]

Have you printed any XYZ calibration cubes, or the single wall hollow thickness cube? 1 of the things it helps with is tuning flow rate.

[dolby]

I've used the XYZ calibration cube and i measured the filament (10cm) to have the correct filament flow from the extruder.

[Ender5r]

Although they're related, extrusion rate & flow rate are 2 different things. Extrusion rate calibration ensures that, when you ask for 100mm of filament to be extruded, the extruder actually feeds 100mm. Flow rate can be used to adjust things like wall thickness. At least, that's the way I've found it to work.

[Geit]

I've used the XYZ calibration cube and i measured the filament (10cm) to have the correct filament flow from the extruder.

So you calibrated your printer to the current filament and the current slicer settings. Calibration cubes are to detect flaws in print quality on different axes, the surface quality and to some extend the cooling capability of overhangs (the letters).

The overall size of the result cube is a software+hardware+filament problem. This is not your fault, done/explained wrong everywhere and you are not the first.

The step values for X,Y and Z are "steps/mm" and not "steps/(actual slicer settings+filament quality)"

If you tell the hardware to move a specific distance, it should move exactly that distance. If it failed you change the steps for the motor. As you can see no printing is involved in the calibration process.

You need to measure the actual motion of the printer. Move it 50mm and check if it moved 50mm, just like you did with the filament and calculate the "now" and "should be" values just like you did with the cube. In the end the hardware moves 50mm, when you tell to move 50mm. That is proper calibration.

After that you tweak the slicer. It has options to compensate for filament expansion or shrinkage. There is even a hole compensation option in most slicers, but you should get the overall hardware right, before fixing something that may not even broken.

I explained the process and how it is done right here along side with a little print that helps you to mount the calipers to your printer.

https://www.thingiverse.com/thing:4599123

[dolby]

Thank you very much, it helped. I printed the single wall hollow thickness cube and saw that i had 10% to much filament.
I printed the measure tool from Geit and was able to calibrate it perfectly. Thank you very mutch for the fast and precice answers. Now, 3d printing is fun again , before it was part of very frustrating.

[Geit]

I am glad it worked for you and yeah 3D printing can be very frustrating with all its tiny problems gearing into each other.