u/hayden_t

I just got around to measuring my printer power and calculating the chamber heater wattage with a power meter:

bed 90deg stable 160w

then with chamber turned on 60deg, 40% power shown in web (stock) 460w total

then i just kept cranking up the max_power setting, restarting kilpper and testing again

by 1.0 (100%) it was still only about 490w total

that a difference of 300-320w, was expecting more of a change, but maybe thats it, still seems to hit the targets ok.

Heater chamber not heating at expected rate See the 'verify_heater' section in docs/Config_Reference.md for the parameters that control this check.

I just want to share the way you can 'falsely' trigger this error & immediate printer shutdown.

By default (im not sure it can be changed) the chamber heater does not put out heat (0% power) when the bed is not up to the target temperature.

This itself is ok, but QIDI didnt bother to tell klipper when it does this, so kilppers 'verify_heater' safety feature can trigger given the following events.

1. You set (or gcode) sets the bed & chamber temp, eg 90 & 60
2. The chamber will start heating once the bed reaches 90.
3. Before the chamber reaches its target you change the bed temp higher, eg 110
4. Klipper thinks the chamber should still be heating but QIDI has toggled the power to 0% while the bed increases.
5. Given a set time (i cant recall exactly how much) but eg 3mins the 'verify heater' alert will trip and shut down the printer as the chamber didnt heat as it expected.
6. You may have a print underway, as by default the print (and chamber heater) start once the bed is up to temp.

Well that is a big claim, and Im not saying it will fix all problems, as there can be many reasons for this, but I found several related problem with orca slicers default filament settings, that was causing the corners of my prints to warp up.

First I just want to highly recommend "Filaform bed adhesive spray" the stuff works wonders, and is much cleaner, easier to work with, stronger, and last longer than glue stick.

But thats not what this is about, as even with that i was still getting warp...

What it turned out to be were 3 settings in the filament "Cooling" menu:

* "No cooling for the first"

* "Min fan speed threshold"

* "Keep fan always on"

See ASA/ABS is very sensitive to cooling, and generally you don't need any parts cooling, but at high speed and or/and short layer time (small parts) it is still needed.

But having it on always, even at 10% at the start is a killer.

By default it is set with "No cooling for the first" = 3 layers which helps, but its too little, the print is still too flexible at only 3 layer high, so i recommend 10-15 layers first.

Also I set "Min fan speed threshold" to 0, (from 10) as you want it to not run at all if its a large enough part that is being printed. I set the layer time to 40s. (I have max set to 50% and 4s. These 2 can be tweaked, by looking at the "Fan Seed" display mode in the part preview once sliced you can see what the speed will be at certain layers and areas.

And finally the other killer is "Keep fan always on", this also is not needed and should be un-ticked, this allows 0% fan when not needed, creating the strongest warp free prints possible, while it still being able to ramp up for small detail, bridges & overhangs.

Here is an example

https://preview.redd.it/3zyaqfa4xzah1.png?width=864&format=png&auto=webp&s=b2b48d94fdd6746bb05fcdd777e1640b3b729bb2

https://preview.redd.it/81vorq96xzah1.png?width=778&format=png&auto=webp&s=be17a22b0c57800835dc043c21712879bf9d02d4

I suspected effects from heat soak during the initial layer printing, as the chamber heater warms everything compared with the build plate that doesn't really heat much beyond its immediate surface.

The chamber heater is changing during a critical stage of the build (first layer), after the mesh, while the bed is up to temp before the mesh. So alternatively instead of waiting for the chamber to heat and soak, I believe there is no reason not to just delay the chamber startup until after the first layer.

As chamber temp is insignificant compared to bed temp, and during the first few layers nothing is being effected by or needed the chamber heater as the bed is providing more than enough direct heat. The chamber heater really only comes into need as the build progresses higher and the effects of the bed become less and less. I found great results by doing this.

Firstly you need this in the start of your slicer "Layer change G-code"

{if layer_num == 1}
    M118 Starting chamber heater
    M141 S[chamber_temperature]
{endif}

Then comment out chamber start in "Machine start G-code"

;M141 S[chamber_temperature]

And in the printer gcode_macro.cfg PRINT_START macro (and restart klipper)

; M141 S{chambertemp}

If you are using a new heavy roll, eg 3+ kg, it can falsely trigger the filament tangle sensor.
If it fits other models let me know