Print height is smaller than expected

[Ban_D 0]

 

 

Hey guyz !

 

Prints on my Ender 3 Pro are smaller in height (Z axis) than expected. X and Y size however are accurate.

 

I printed some calibration cubes to be sure.

Difference is about 4%, the height is around 19.15mm instead of 20mm.

 

I use Cura to slice STL files. I can increase height percentage at around 104% on Cura but for me it's only a workaround and I would prefer a more durable solution than increasing height each time I slice a file.

 

I double checked:

• E step : perfectly fine
• Z step : same
• Z binding : followed a tutorial on youtube, shouldn't be this, but I can't be sure
• Z axis bar is perfectly flat, no curve or whatever

 

What should I investigate on in order to solve this?

[GregValiant 1,141]

Open a gcode file with Notepad and check the MaxZ (noted a few lines down from the top of the page).

 

 

 

Edited April 13, 2021 by GregValiant

[Ban_D 0]

I have this : ";MAXZ:20"

 

I think it's normal isn't it?

[GregValiant 1,141]

That was the height of the top layer and it's what it should be.  It sounds like the machine is shorting the dimension.  There are a couple of things you can look at.

 

Make sure the coupler on the Z motor isn't touching the body of the motor.  There should be 6 or 7mm clearance.

Check that the set screws in the coupler are tight.

With the printer auto-homed - is the Z screw parallel to the aluminum upright?  If it isn't then that can cause Z binding when the Z is at 0 to some distance above 0.

 

If you don't find an issue with those three then:

The default Zsteps/mm is 400.  Your print tells the story (20/19.15) * 400 = 417.75.  So you can try setting the Zsteps/mm to 418.  Print another cube and measure it.

 

The X, Y, and Z steps on the Creality printers don't usually need adjustment once a printer has worn in.  That doesn't mean they never need adjustment.  On the other hand, the Esteps usually do need an adjustment and need to be revisited about once a month.

Edited April 15, 2021 by GregValiant