Retraction in change of extruder

Sovol SV04 IDEX
1

I have a problem with the code generated by Cura for a double extruder impression. I want to use the right extruder with PVA to print the supports. Every time I need to clean the heatbreaker that it’s clogged.
After some study I discovered that when the machine finish a layer of supports and changes to the left filament, the extruder sends back a lot of filament and it clogs. I have a value of 0.8mm of retraction in Cura 5.3 but this retraction at the change of extruder isn’t afected.

I took a gcode and after study I discovered that everytime that the machine changes, it retracts 1.6mm. I checked that it isn’t the double of the retraction. Although I select “no retraction”, it retracts the 1.6mm before to cold a bit the hot end. This so long retraction clog the heatbreaker everytime that it finish a support layer and change to the print extruder.

Anybody know how to change this value in Cura? I checked the printer parameters, all the options,… and I need a “normal” retraction and not this 1.6 mm value, at least working with PVA that it’s very soft, elastic and very adherent.

2

Finally I found.
In the double extruder section there is an adjust called “retraction distance in change of extruder”. By default is 16mm and causes the clog. I wait that can help others

3

I use here 16mm and didnt clogs…

my clogs problem was solved with replace ptfe inside extruder (i put with more lenght inside) and changed the position of fan (fan that when we turn on the printer its start… creality 4041).

4

With 16mm it isn’t a problem with PLA. But using PVA or Nylon it’s really a nightmare.
After reduce it to 4mm no more clogs. I prefer to retract more than use a long value here.