CoreXY printing very slowly

Etaardvark

I've just converted my Sapphire Pro to a Duet 2 Wifi board, and i've got all of the wiring working correctly.

However i've started printing test objects to start tuning the printer and i'm seeing very slow print speeds (approx 6-8 mm / s speed).

I've tried slicing the object with both Cura and Prusa Slicer with a default speed of 45mm /s, but in both cases it appears to be a firmware limit. I've checked and both slicer profiles are configured to generate RepRap firmware G-code - at first I though it was generating Marlin Firmware.

What is odd as well is when printing, it looks to 'pause' between lines of G-Code (e.g. it moves to the start of the brim, then pauses for maybe half a second, before starting to print).

I've spent a few hours looking at this, and haven't seen anything obvious in the config that would limit it.

Board: Duet 2 WiFi (2WiFi)
Firmware: RepRapFirmware for Duet 2 WiFi/Ethernet 3.2.2 (2021-02-11)
Duet WiFi Server Version: 1.23

I've attached my config.g / config-override.g files, any suggestions appreciated - its probably something obvious i've missed.

config-override.g
config.g

hamel

Just my glancing observations...

Your steps per mm and extruder acceleration values look a bit off. A pause during retract could be too slow of a retract either due to slicer retract speed being too low, or due to your very low acceleration values for the extruder drive. Is this happening where retracts are happening, or at line segments? For the overall print speed, is this happening on all layers, or just the first few? Cura has slower speeds for initial layers as a setting. When you jog the printer, does it do rapid moves at a standard rate?

Etaardvark

The extruder steps per mm i calibrated before i started trying to print, as i've just switched to a E3d Titan geared extruder.
The Sapphire Pro is a bit odd, as the Z axis is very slow compared to the other axis.

The pauses seem to be occurring between lines of G-Code - for example, it extrudes the perimeter, then pauses, and starts the infill, gets to the end of the line then pauses, and starts again.

Didn't seem to make any difference past the first layer, when it should have speeded up.

I'll try disabling retraction and see what difference that makes

Phaedrux

Can you post a sample gcode file from each slicer?

Also post your homing files.

hamel

Sure sounds like retraction is causing the pauses. I would try without retraction, and if that fixes it, you'll need to adjust the config.g. I was talking about the relationship of your steps per mm to your acceleration values, not pointed at your steps per mm. To move 1mm, it would take a ton of steps, reaching a higher speed, and to do that in the same amount of time it would take higher acceleration values. It would be dependant on retraction speed, retraction distance, and your drive settings for that drive.

Others here are much more versed in RRF that I am, but I have seen that issue caused by retraction settings in the past.

Phaedrux

M566 X900.00 Y900.00 Z60.00 E120.00            ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z180.00 E1200.00        ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z20.00 E250.00            ; set accelerations (mm/s^2)

Well your Z and E speeds are very slow, so things like layer change, retraction, pressure advance will slow down at those points.

Try these values instead.

M566 X900.00 Y900.00 Z60 E2000            ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z600 E6000        ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z200 E3000            ; set accelerations (mm/s^2)

Etaardvark

@Phaedrux said in CoreXY printing very slowly:

X500.00 Y500.00 Z200 E3000

That in combination with an errant M201 in the startup G-Code seems to have fixed it.

Probably the classic issue of taking the values from a saved Marlin config and transposing them.

Thanks for the help