’nother 3D Benchy with bow warp problem… I guess. I’m still somewhat of a 3D printing noob, so it might be something totally different.
Preface
I could print just fine for months before a botched firmware update completely bricked the printer. I chose to give the open source firmware project ‚OpenNept4une‘ a chance and installed that instead of Elegoo’s own firmware. This was harder than expected (remember: me = hobbyist / printing noob), so it took me all summer and good parts of fall 2025 until I was being able to print at all. Now I have to dial it in completely from zero, and some problems are harder to solve than others. The following one ate up most of my Saturday until I gave up.
Why here and not on support boards?
I posted the following in a 3D printing support board on facebook after failing to solve the problem myself (started in the morning, now it is well past 9 pm). I intend to ask around on other boards & platforms as well, where I then link to this posting instead of typing everything from scratch.
My hope is not only to get my own problem solved with help from others but to add the solution in an update for other people with the same problem.
My setup
Trying to give all the relevant information (screenshots from Orca slicer showing relevant settings), pls ask if something is missing.
Printer Hardware: Elegoo Neptune 4 Plus
Firmware: After a firmware update bricked the printer, I decided to get rid of Elegoo’s firmware (which got much and harsh critique) and installed the open source firmware package OpenNept4une (v0.1.5-558-g084a0e5c) on the printer itself.
Software: Fluidd (v1.34.3 with Klipper (v0.13.0-190-g5eb07966) & Mainsail (v2.14.0) and Orca (Version 2.2.0) as slicer
What happenes a.k.a. problem description
The Benchy’s bow (i. e. right side of the boat) warps upwards, and after a while the first layer below the bow increasingly fails to stick to the bed (I already use a gluestick to improve stickyness) until the benchy gets ripped of the bed.
See the following video for details (sorry that I couldn’t get the focus better).
The warping is only on the right side – the left side is (almost) completely flat. Also, you can see the first layer below the bow is warping upwards. I guess it gets drawn up by the following layers who’s warp pulls the layers below them off the bed.
The bow warp is better visible when flipping the Benchy upside down:
To show that only the bow warps: Here’s how it looks when the bow is off the table – the Benchy lies almost completely flat on the surface, indicating that the rear/stern/aft shows only minimal warping.
I (think I) have gotten bed levelling more or less right. I did a manual levelling with the bed screws, a complete auto-mesh bed levelling and took care of the Z offset. The 4 test squares I printed afterwards look more or less OK to me:
Slicer settings in detail
As most users attribute the ‚warped bow‘ problem to cooling, I turned the printhead fans off for the first 4 layers, then set them to 100%. The Neptune’s large fan is turned off (as it had always been for the previous months of sorrow-free printing joy).
Not sure what else might be relevant, so here’s a whole bunch of screenshot from various Orca settings. If there’s something missing, fire away and I provide more details.
Quality
Speed
- First layer speed is reduced from 50 to 20mm/s.
- Not sure ‚Number of slow layers = 0‚ is correct.
- I also reduced the First layer infill speed and the outer & inner wall speed settings.
- ‚Slow down for overhangs‚ is activated, I didn’t change any speed settings there.
Cooling
No cooling for the first 4 layers to get better adherence to the bed, then 100% fan speed to get the molten filament cooled asap to avoid warping (which apparently isn’t enough to prevent it).
Also, force cooling for overhangs = activated, as the Benchy’s bow is where the overhangs are most pronounced.
PLA Filament settings
Not sure there’s anything important here…
Any advice is welcome.
Especially but not only from those who use the same setup, i.e. a Neptue 4Plus with OpenNept4une, Fluidd and Orca.
However this might be a general problem, so fire away if you feel you know what’s going on.