I just sent this email over to elegoo official, so either way I'll update this post with their response for a community reference point:
"Hello, I'm having issues with my Elegoo Neptune Pro 4. I've tried following the official documentation and other resources to help fix my issue to no avail, so I am reaching out as a last ditch effort.
My issue mainly pertains to PLA prints consistently being ruined partway during printing after a few months of use and operation.
Specifically, my print will successfully complete the first few layers. Then, at some point, the print will somehow 'grab' or 'catch' the print base and drag it around the print bed, ruining the print and causing a large build up of filament at my hotend. This then requires cleaning.
From what I have seen, this can be caused by issues with the print bed not being clean or the temperature of the bed in relation to the fan speed. For example, having a low fan utilization at the beginning, then ramping up later in the print is supposed to help this issue. However any fixes I tried returned null results.
Some background info, I purchased the printer on preorder and received it in September 2023. I have kept up with maintenance. Namely, keeping stepper motor tracks cleaned and greased properly, belts tightened, the print bed is wiped down with 90% ISO alcohol between prints. I have replaced the hot-end when I first started experiencing print issues, and again during the troubleshooting process to further diagnose the problem. My Z offset seemingly is "correct". I followed the mfg instructions closely, and before this issue, my prints were coming out beautifully.
Print Settings: Using Elegoo brand PLA 1kg filament rolls. Default Elegoo Cura print settings applied for temperature, speed, fan speed, nozzle size, etc. Supports or No supports didn't make a difference during my troubleshooting. Brim printing mode is my default.
For the 4-5 months that I've had the Neptune Pro 4 has been absolutely amazing. Fantastic quality, consistent, very easy to use and maintain. The issues I'm experiencing are beyond annoying and I can't seem to figure it out myself.
Is this issue known? What are the recommended solutions?"
- Let me know if any of you have experienced something similar to this and how you addressed it!
EDIT: This is likely solved. There are many issues that can contribute to this issue but TLDR quadrouple check your z offsets. Read the thread for other good info.
Hard to know what's going on without pictures. Could be any number of things. My first thought is over-extrusion if the nozzle is catching your print and knocking it over. Or maybe you need Z hop between layers. I've only used Prusaslicer so can't say what to do to help in Cura. If you've completely replaced the hot end, you should be re-tuning your printer (PID tuning for correct temps, e-steps for correct extrusion amounts, etc). If it's adhesion problems where the print isn't sticking to the bed, applying some glue stick can help keep things secure.
Thanks for taking the time to reply, and with so many different options to try. It means a lot, I really enjoy printing so this has been bumming me out a lot. I'll try to get some reference photos up after work.
Printing really is fun! But there's so much to troubleshoot, it's a time sink to get things right. My 2nd printer is down from a dead fan, one of these days I need to solder the broken wire back on.
But once your printer is tuned, oh boy it's satisfying
Also, depending on the amount of contact area on the bed, you may want to try a brim. Taller items with a small contact patch can be prone to this.
Oh this for sure. Sharp corners? Brim. Tall print? Brim. Small contact area on the bed? You won't believe it, but brim.
Good call. I tried the all options, and brim definitely helps get good consistent prints. It didn't solve my problem outright but definitely helped when I was doing initial research.