# Too long time to wait for M109 to stabilize when changing extruders

I've got 2 extruders and 2 nozzles, they are working fine. I'm printing from Ultimaker Cura 4.1 generated files. I have problems with temperature stabilization when changing extruders.

What happens is this:

Prints from one of the extruders (E0 first). Then it goes to switching to E1, so it heats E1 and cools down E0 (to 175 °C, configurable in Ultimaker Cura). Very quickly temperatures are established, but Marlin seems to have problem seeing it (Possibly they are always +/- 1 degree above or under desired temp. I decreased Time Hysteresis, and increased temperature gaps but still facing the same problem. Sometimes changing from one nozzle to the other one takes 40 minutes!. After the temperature is finally stabilized it prints correctly. But another change from E1 to E0 will cause another next 20-40 minutes of waiting.

Does someone knows how to properly set or what should I set - since changing Hysteresis seems to not change anything (even if changed from 10 to 2) Maybe some different parameter is for me to use?

I've decreased residency time and still nothing. I've got 4 seconds now in the configuration.

I've tried PID tuning with M303, but no changes with this.

Configuration looks like this:

#define TEMP_RESIDENCY_TIME 4
#define TEMP_WINDOW 5
#define TEMP_HYSTERESIS 6


But still this waits for too long for M109 to stabilize.

Ultimaker Cura changing code looks like this:

G92 E0
T1
G92 E0
M105
M109 S190
M104 T0 S180
G1 F1200 E9.5
G1 F600 Z4.3
G0 F7200 X161.114 Y156.121
G0 X159.678 Y157.201
M104 S200


Probably changing all the M109 to M104 would correct this but this is nasty workaround.

Printer is modified Tevo Tarantula.

• Why do you need to stabilize the temperatures on each nozzle change? Aug 22 '19 at 18:10
• i dont need it. Cura just do this by default. If someone know how to disable this in cura - it would also solve my issue. Aug 26 '19 at 6:04
• How are you measuring the nozzle temperatures to know that the temperatures have stabilized? If not through the thermistors, then there are several avenues to explore.
– cmm
Sep 18 '19 at 17:53
• Yes, through normal reading on the display, so it's through thermistors. Sep 20 '19 at 9:47
• This is a delayed follow up. Sorry. The display shows both head temperatures? I've mostly run multi- head through Repetier Host with a printer that lacks a display. RH only displays the selected head temperature, although all heads are available in the log file.
– cmm
Oct 14 '19 at 1:49