Struggling with PID tuning on Duet 3 with custom CoreXY

[aria_james]

Hey everyone,

I’ve just finished building a custom CoreXY printer using a Duet 3 board, a Smart Effector, and a high-flow hotend. The setup runs great overall, but I’m running into some issues with temperature stability — especially during longer prints with higher flow rates. The hotend temperature tends to drift a bit, and I’d like to tighten it up.

I did the usual auto-tune, but I’m wondering if there are better ways to manually fine-tune or improve stability, especially for materials like ABS or Nylon that are a bit more sensitive. Has anyone dealt with this kind of issue on a similar setup?

Any advice or experience you can share would be really appreciated!

[gloomyandy]

@aria_james It would probably help if you could post a screenshot showing the sort of temperature variation you are seeing during a print.

[dc42]

@aria_james said in Struggling with PID tuning on Duet 3 with custom CoreXY:

The hotend temperature tends to drift a bit, and I’d like to tighten it up.

When you say it is drifting, is that when the printer is idle or when it is printing? As it's a high flow hot end it's common to see the temperature drop when it starts extruding at a high rate. You can configure heater feedforward to combat that.

[droftarts]

@aria_james

@dc42 said in Struggling with PID tuning on Duet 3 with custom CoreXY:

You can configure heater feedforward to combat that.

See https://docs.duet3d.com/User_manual/Connecting_hardware/Heaters_tuning#heater-feedforward

Ian