Need help please, new to 3d printing

[jamesma]

Need help please, new to 3d printing，I have had an Ender 3 pro for a couple weeks now, everything has been going great for the most part. ive just noticed one issue ive had on at least the last 3 prints for sure. As it is printing when it gets to 1.63mm in the Z axis, it prints that layer and then always drops down to 1.57mm and prints another layer. Seems to print fine after that, i havnt noticed it drop down again any other time while its running. I can hear it even just barely scraping the plastic as it goes back and forth. Been running 60mm for speed, .15mm layer thickness, 200C. Doesn’t seem like a level issue. Im not sure if this is something i accidentally did in cura maybe? Any suggestions would be appreciated!!

[CrazyIvan]

Welcome aboard.

I have no specific knowledge of Ender, but FDM printers are all pretty similar.

As it is printing when it gets to 1.63mm in the Z axis, it prints that layer and then always drops down to 1.57mm and prints another layer.

It would help to know how you know this. If this is by watching the control panel and it shows the Z decreasing by 0.06mm, then this seems to rule out mechanical problems.

I can hear it even just barely scraping the plastic as it goes back and forth.

Really? Why would that be? 1.5mm is a huge clearance, and even when Z=0 there should be a slight gap between the nozzle and the plate (usually described as the thickness of a piece of paper).

Printers are essentially dumb followers of the instructions given to them in the form of gcode. You mention Cura, so I presume you are doing your own slicing rather than relying on ready-made gcode. I can't think of any reason any printer would need to drop down half a layer, but check you are using the Cura presets for Ender 3 Pro.

Another thing you can do is examine the gcode file in a plain text editor or on-line gcode viewer (I prefer the former). You can look for Z movements and find the instruction which moves it by -0.06mm. If there isn't one, we're back to looking at mechanical problems.

[bryant]

it could be caused by a few different factors. Here are some potential solutions:

Z-axis Calibration: The problem you're experiencing might be due to inaccurate Z-axis calibration. During printing, if the Z-axis is not calibrated correctly, it could cause the print head to print at the wrong Z height. You might try recalibrating the Z-axis to ensure the print head is printing at the correct height.

Slicer Settings: You mentioned using Cura software, and it's possible that some parameters are not set correctly in the slicer settings. Check the Z-axis offset settings in Cura to make sure there are no incorrect height offsets. You can try adjusting the Z-axis offset to see if it resolves the issue.

Print Speed: You mentioned using a speed of 60mm/s, which is relatively fast. Printing at high speeds can lead to imprecise positioning of the print head on the Z-axis. You might try reducing the print speed, such as lowering it to 40mm/s or even slower, to see if there's an improvement.

Layer Thickness Settings: You're using a layer thickness of 0.15mm, which is quite thin. Layer thickness settings have a significant impact on print quality, and too thin layers can lead to instability during printing. You might try increasing the layer thickness to 0.2mm or thicker to improve print stability.

Temperature Settings: You're using a temperature of 200C, which is suitable for most PLA filament, but if your filament has different temperature requirements, you may need to adjust it. Make sure the temperature you're using matches the recommendations from the filament manufacturer.

Mechanical Issues: Check the printer's mechanical components, such as belt tension and bearings, to ensure they are in good working order. Any mechanical issues could lead to inaccurate movement of the print head on the Z-axis.

Firmware Update: Check if there are any firmware updates available for your Ender 3 Pro. Sometimes, firmware updates can resolve printing issues.