Safe idle temperature for second nozzle printing PVA

[Falc.be]

The need is growing for a feature that can turn off the second nozzle in a dual setup when the nozzle is not required for a certain amount of time. and turn it on again in time

materials like PVA or scaffold can burn up after being idle to long in a nozzle and cause clogging

[benwfowler]

Hi,

There is already this feature. Well Kind of. If you add this:

{IF NEWTOOL=0}M104 S170 T1; turn temperature down when switching from extruder 1
{IF NEWTOOL=1}M109 S[extruder1_temperature] T1; turn temperature up when switching to extruder 1


to the tool change script section, it should cool it down to 170 when not in use. (this is if the PVA is in Extruder 1)

[Falc.be]

This would increase print times tenfold

I am very disappointed this feature has not been added in 4.0 especially since dual extrusion is becoming main stream

[maker2]

Turning the nozzle down (or off) with every tool change is not the same as only turning it down/off if it's not going to be used for a Long Time.

The slicer is uniquely placed to evaluate this and set up the G-code appropriately.

Trouble is, don't know how to say this in a simple way?

"If anticipated period of inactivity is greater than: INACTIVITY_THRESHOLD

Reduce temperature to: SLEEP_TEMPERATURE "

Yes this requires a bit of programming (scanning original G-code for intervals of inactivity, then inserting appropriate Temperature down / Temperature up commands) but it's exactly number crunching like this that computers are so good at!

ps and of course the command to bring the nozzle back up to temperature again is inserted in the G-code an amount of print-time before it is needed so that minimum waiting for nozzle temperature to stabilise. Might need a third parameter for that "TIME_TO_REACH_TEMPERATURE_FROM_SLEEP" since slicer doesn't have PID information.

[Ayres3D]

I think that this would be very useful. I had call for precisely this. I was printing something with quite high supports and thought I'd use the new facility to print dense supports with the second extruder (PVA). By the time the print reached the top of the support, the PVA had cooked and the nozzle was blocked.

I'm not sure whether it could be achieved to a degree with separate processes, and change the temperatures there, but even then it would only work if the tops of the support were at the same height - which is unlikely in most cases.

[newt80ns]

Adding another request for more advanced temperature controls. I've had to go back to Cura for my dual extrusion printer. S3D's tool change only handling method adds hours to each print, often requiring more time to be spent heating the tools vs extruding.

Here's an example of the temperature control I'm getting with Cura, you can see the new tool comes up to temp while the old tool is finishing that layer, as soon as the old is done I do a quick purge into a catch bin, then I'm off and printing with only a 2-3second delay for the tool change max. In that screenshot you can see Cura detects that tool 1 is only getting a brief use, so it doesn't even bother dropping the temp on tool 0.

[WTLgrinda]

Bumping this thread.

Just a suggestion but an easy way to implement this in would be to add an “idle temperature” to each hotend/tool. When the part is getting sliced, the software knows approximately the time between each operation and could start off nozzle heating before the actual tool change. This would save a lot of time that is wasted heating up the nozzle of newtool and waiting for it to stabilize.

[Falc.be]

Bump2. This missing feature has now cost me a un un- uncloggable nozzle

[Suckiden]

just wanted to get this thread running again. I totally agree with the previous statements that having a feature that can "smart" cool down the PVA (second) nozzle while not being active.

Would be nice if we can get a statement on this from the developers.

1. Yes we're working on it
2. We don't plan to add this feature in the near future

Otherwise I see no other option to get hands dirty and write a post-processing script for the g-Code

Another nice but I guess rather simple feature would be to be able to cool down the PVA nozzle after last use. Currently I manually search the g-Code for the last tool change and add the temperature shut down command. Or is there already a feature I don't know that allows to shut down nozzles after last use?

[michalsok]

+1 for me.
This would be a great feature. I would also suggest the solution quoted.
Thanks.

Bumping this thread.

Just a suggestion but an easy way to implement this in would be to add an “idle temperature” to each hotend/tool. When the part is getting sliced, the software knows approximately the time between each operation and could start off nozzle heating before the actual tool change. This would save a lot of time that is wasted heating up the nozzle of newtool and waiting for it to stabilize.