I can’t get my Wanhao Duplicator i3 Plus bed temp to stabilize and it seems to be causing issues with my prints.
The machine has been updated with a Micro Swiss all metal hot end, an all metal direct filament drive, a rear mounted 3D printed cooling fan mount with 3D printed duct, and a Wham Bam PEX flexible metal magnetic bed.
For months and months it printed absolutely perfectly with the PEX bed. Lately I either get very good print adhesion except pulled up corners. Corners, like on a box, are now consistently pulling up and away from the bed. The layers above the base few, seem to be shrinking inwards and pulling the corners up. It isn’t an issue along the sides away from the corners,
If I set the bed temp to 70 I get generally good bed adhesion but I still get shrinkage in the layers above the first layer (something about layer 10 I guess) resulting in the side walls being pulled in and the corners of the print pulling up and away from the bed. It looks like crap and depending on the model it results in a print that doesn’t function as designed.
The print adhesion for the majority of the flat surface is perfect, just the corners seem to pull up. I do not use tape or glue or any other surface prep because that was the entire reason I purchased the Wham Bam PEX surface - non of that is needed. And up until this problem raised its ugly head a few months ago, the curling up corners wasn’t an issue.
This seems to be a relatively new problem for this printer which used to print divinely. The problem showed up in late November/early December.
When printing, the bed temp can fluctuate from +/- 5 degrees on a good day and sometimes as much as +/- 10 degrees or even more some times. I honestly do not know if this is a new problem or one that’s been happening for months and I just didn’t notice.
I suspect the problem, or a least part of the problem, is the inconsistent bed heat temp and/cooling fan speeds.
I’ve done a bed temp and hot end PID autotune several times and that doesn’t seem to help.
My first layers look perfect. The squish is great, the fill is perfect, the print always gets off to a perfect start. The problem seems to occur once a couple of layers are printed and the cooling fan kicks in
Might I be on track or could it be something else?
What might be causing the bed temp fluctuations? A bad thermistor? A bad bed heater? Something else? How should I diagnose this issue?