Extruder temperature set point changes - Hardware, firmware and software help

RE: Extruder temperature set point changes

Giacomo — Thu, 01 Aug 2024 12:12:08 +0000

M140 S ; set bed temp

M104 T0 S210 ; set extruder temp for bed leveling

M109 T0 R210 ; wait for temp

M190 S ; wait for bed temp

This is the part of the G-Code where I set the temperature for the mesh bed leveling at 210°C.

Can you check if this is correct please?

Cheers

Giaco

RE:

Giacomo — Thu, 01 Aug 2024 11:54:26 +0000

Great!!! This is exactly what I was searching for! I have a MK3.5 with a Revo 6 Extruder and I print allways with PETG. This Temperature settings at 175°C for the mesh bed leveling is the cause of the cloggings that I have been having with the nozzle 0,25 mm since I updated the printer from MK3S to MK3.5. Before the Upgrade I never had a nozzle clogged. Now suddenly I had two majore clogs in 4 Days and the Revo 6 Nozzles are very difficult to clean. Absurd. I will set that temperature to at least 210°C.

Another option would be to enlarge the time laps in which the temperature changes between 175°C and 250°C(my normal print temperature). But I have no idea how to do that.

Thanks a lot and Best Regards

Giacomo

RE: Extruder temperature set point changes

JoanTabb — Sun, 18 Feb 2024 20:08:41 +0000

Cheers Matthew.

regards Joan

RE: Extruder temperature set point changes

Matthew Oliver — Sun, 18 Feb 2024 19:05:53 +0000

Sorry, I’m not being clear. Thanks for the detailed explanation! It’s helpful.

The issue isn’t the programmed temp changes that I can see in the Slicer setup. With my temp change concern when I saw the #’s changing I attributed it all to the same cause, when it’s not.

What happened was a PETg print resetting the nozzle temp to 175 part way through the printing. That’s what trashed my 10 hr run. I observed the same thing with a second file I’ve printed multiple times. I caught it as I was watching.

There’s no 175 in the slicer file, which I’ve confirmed.

maybe this is a one off event - I’ll watch my long print closely and see if it repeats.

thanks again!

RE: Extruder temperature set point changes

Matthew Oliver — Sun, 18 Feb 2024 18:14:43 +0000

I get there could be deliberate temp set point changes in the code, but they didn’t manifest before printing the same gcode.

In any event 175C for PETg would be a fail, which I suspect is why my print failed due to low flow. The clicking was the extruder gear attempting to advance the filament when it wasn’t melting quickly enough. Once I corrected the temp it’s been working fine.

The mystery is how a PETg print changed the nozzle temp to 175, when it never happened before. Tbc, I’ve printed this exact file 6 times already without this happening.

The printer still recognized it was a PETg print. Recommended nozzle range for this material is 225-250.

Same question - unexpected temp set point changes experience by anyone else?

RE: Extruder temperature set point changes

JoanTabb — Sun, 18 Feb 2024 08:19:18 +0000

The Prusa Mk4 Profiles in Prusa Slicer are designed to preheat the nozzle to a reduced temperature during start up. in order to reduce the chances of contaminating the build plate with spots of filament, during mesh bed levelling, the heatbed is fully heated at this time to stabilise it for mesh bed levelling, and prepare for the first layer of the print.

After mesh bed levelling the printer pauses and raises the nozzle temperature to the first layer temperature, before starting the first layer of the print.

at the end of the first layer, the printer then changes the nozzle and heatbed to the new temperatures for the remainder of the print

It would appear that what you are observing, is the correct, programmed sequence of events

the start temperature is set within Printer settings>Custom Gcode>Start Gcode In prusa slicer
and the first layer and other layer temperatures are set within Filament Settings>Filament>Temperature in Prusa slicer

so the only issue is why was the extruder clicking? and reduced filament flow. did you find anything unusual when you cleaned the extruder?

regards Joan

RE: Extruder temperature set point changes

Matthew Oliver — Sun, 18 Feb 2024 02:19:02 +0000

And part way through the print I notice both the nozzle and the heat bed temps are shifted. 230 -> 245 and 85 -> 95.

Extruder temperature set point changes

Matthew Oliver — Sun, 18 Feb 2024 00:52:21 +0000

Middle of a 10 hr print found the sidewalls only had about 40% of the material. The extruder gear was clicking so expected a jam. Cleaned everything up got new filament fed.

restarted a shorter print.

first thing I noticed, this Petg print that was set at a nozzle temp of 230C and I’ve printed 5 times so far with the printer at 230C, had reverted to 175C.

manually set the nozzle temp to 230C. Few minutes later I look at the nozzle is now set to 240C. It seems to stay at 230C now.

Latest firmware and version of slicer. And it was working fine yesterday.

Anyone else had nozzle temp change on its own?