New SV04 leveling issue. Center position higher than corners

This is my first 3d printer. After months of research. I decided on this printer mostly for the Idex features.

I’ve spend dozens of hours on the printer most of which on leveling and still can’t get it correct.

I can get the 4 corners all the same but the center bed is always too low.

I have tried to eliminate variables. Ran the z auto allign and bed measuring. Then i used metal right angle rulers to measure if the gantries are perpendicular and they sure look like it. Put ruler on bed with leveling knobs completely removed and no gapping and cant even slide paper between.

Then i got metal feeler guages instead of paper for bed leveling so i can attempt a definative depth. This helped alot. Even after all that and hours more over several days i cant get the corners to match the center. I know the center is effected by the corners but to get the center low enough the corners would almost need to dig in too deep. I’ve tried loosing corners to raise all depths then use Z depth adjust to adjust. Got closer but still can’t get even. Warming to 60C before atempting levels.

I can get corners the same but center is according to my feeler guage about 0.04-0.05mm low by adding thin strips and seeing when it touches enough. This is better than my 0.1 mm off a week ago. Basically its a full sheet of paper off. Not sure on tolerances but thinking that is too much.

Tried a few test prints with calibration combs. Left waste line good. Center triangle has issues. Bottom edge not sticking, diagonal ok and left side good. Tried lower depth slightly. Slightly better. Ive done this about 5 times and plastic filiment residue on plate. Tried gentrly cleansing it with warm water and napkins. Got enough off i couldnt feel the build up. I will try again and see if that was preventing adhesion. I had depth ago weeks ago to do combs but then got feelers and right angle and started over with leveling.

Im just not sure what im doing wrong or how to fix it. I think its all operator error but i go between being frustrated, sad and hopeful.

The problem you are describing describes my situation exactly. It is as though my print bed is slightly bowl-shaped. When duplicate printing, the left nozzle (1) will adhere well, but the second print (nozzle 2) on the middle section of the print bed, will often not adhere…
I fiddle with the leveling knobs on the right to get the first layer to stick and then after that all is good, but this is very ‘fiddly.’
I had hoped that the 16-zone bed calibration would somehow fix this, but it doesn’t seem to matter…
I, too, would love advice on this.

Ya i too had assumed the 16 zone mapping would prevent such silly things but it does not. Still seems to need the 5 point leveling to be accurate. Sort of felt missled when its literally called auto leveling. The only auto leveling is the Z axis but it again assumes you got it as close as humanely possible first. I knew 3d printers weren’t plug and play but didn’t think it would take me more than an hour to be up and running.

I will keep fiddling and try again since i cleaned the bed. If that doesnt do it i will fiddle more on reveling.

What irritates me is my brother inlaw who sort of got me into this because he got an ender 3 this summer has had few issues. I ask him about leveling and if he checks the center point. He didnt know that was a thing and has never done it. That has happened on several things he didnt know or do his research on but luckily it just works for him.

Maybe its harder leveling a bigger bed

Hi, I basically have the same issue (I think the title should read "Center position lower than corners?).
My corners are almost exactly at the same height, with a delta of 0.02mm.
Of course the bed sags in the middle, because it is not supported there. That applies to almost all printers. But the difference for me is actually 0.4mm from the corners to the middle, which is two whole layers for my print settings.
Dual color mode works perfectly, which means, that both extruders are exactly on the same Z.
But when I print something in copy mode and the left printer is at X=0;Y150, the right extruder is at X=150;Y150 and therefore 0.4mm too high. Even worse: when the left extruder is close to the middle, the right extrudert can scratch the bed during the first layer…
I already increased the initial layer height to 0.3mm, but that barely helps.

I had the crazy Idea to put some kind of spacer below the middle of the bed, so it can’t sag anymore. Any thoughts on this?

By the way, this is my bed visualized with an Octoprint plugin:

Yes i should rename the thread. Is it possible yo rename it?

Sovol does offer silicone spacers which they claim can help with stabilizing each corner with less spring changing over time. Im not wanting to spend any mors money than i have on a thing where im not sure if its the product or operator error.

Ya id live a center support. Frustrating that changing any 1 corner effects all but 1 of the corners across from it and middle.

I will kerp trying to lower the corners evenly to get a flat bed.