kodachrome
Posts: 10
Joined: Tue May 05, 2015 6:34 am

Shared Nozzles - different temps - how??

I'm going around in circles on this one, this is the 3rd forum as the 3rd part of this messed up trifecta of problems (S3D, Filaswitch script, Duet Wifi).

Basically, have Rostock Max (with Duet firmware) with Prometheus multi filament system (shared single nozzle with splitter). Want to print different filament at diff temps (support and say PLA). In theory all the parts of this system support this.. but its not working as intended.


Duet supports this, but is getting messed up as S3D is sending the "other" extruder nozzle temps as separate extruder nozzles. This means the last temp set (eg 210c for Extruder 2) overrides the current active temp (eg 190c for Extruder 1), making it a complete mess when using prime tower scripts and generally mulitple extruders. Everything gets jumbled up and the wrong temps are becoming active on the single extruder as it tries to print.

See here:
https://forum.duet3d.com/topic/5055/tem ... laments/12


Is this a (crippling) limitation of S3D's multiple extruder support or am I setting it up wrong?
airscapes
Posts: 377
Joined: Tue Mar 06, 2018 10:35 am
Location: Philadelphia PA Area

Re: Shared Nozzles - different temps - how??

If you go to the temp tab you should see both extruders on the left along with the bed heater.. click on the one you want and alter the temperature on the left side .. if you want to change temps at a specific layer you can add a set point with the layer and temp. I don't have a duel but that looks to be the way it works.
kodachrome
Posts: 10
Joined: Tue May 05, 2015 6:34 am

Re: Shared Nozzles - different temps - how??

Well yes that kinda is how it should work! In that tab you can add a new Temperature Controller and each one must have a unique Temp Identifier (or else S3D complains).. I think this bit it is the problem as they are actually not separate identifiers as there is only one temp probe and one extruder hotend. It should allow each "Extruder" to have different temps but only measured via the one controller and only send the temp change command with the Tool Change.

Whats happening is: When you add new Temp Controllers (with unique IDs) S3D slices these to Gcode as if they existed independently which means the Duet (and in theory all firmwares) simply apply these erroneous new temps to the last/current Temp Controller, over writing the correct (current) value.

Eg:
Ext0 is set to 220c
Ext1 is set to 199c

What appears to be happening:
When it starts printing it sends M104 S220 T0 (which is correct) but then also tries to setup the next extruder and sends M104 S199 T1 (which is incorrect). Doing this overwrites T0 temps to 199c, screwing up the print if you needed different temps!
kodachrome
Posts: 10
Joined: Tue May 05, 2015 6:34 am

Re: Shared Nozzles - different temps - how??

So anyone have any theories or thoughts? I can't be the only one with a shared nozzle setup??
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DarthRevan
Posts: 479
Joined: Wed Feb 18, 2015 8:29 am

Re: Shared Nozzles - different temps - how??

I'd use a toolchange script. The following is an edited excerpt from the tip of the day for the scripts tab:
Tool Change G-Code:

This tab will insert G-Code on tool change commands. These commands can help do a ton of things for multiple extruder prints, especially if using the IF command functionality. For instance, if you wanted to change the temperature of your extruders (T0, and T1) for each tool change switch:

;begin tool script
T[new_tool]
G28 X0 Y0; homes X-Y axis
{IF NEWTOOL=0}M109 S220 T0; Set T0 to 220 and wait for it to reach temperature before proceeding.
{IF NEWTOOL=1}M109 S190 T0; set T0 to 190 and wait for it to reach temperature before proceeding.
;end tool script
So this would send temperature updates to the T0 heater based on which tool is being selected for extrusion. I don't completely know the syntax for what your firmware expects to be used in order to heat the shared heater, so I'm assuming here that it wants temperature commands sent to T0 but still uses T0 and T1 tool change commands to switch the active extruder motor.
kodachrome
Posts: 10
Joined: Tue May 05, 2015 6:34 am

Re: Shared Nozzles - different temps - how??

That is a good idea, though would have to be incorporated in some manner in the existing Dual Filament Script Im using with the Promethea System (Filaswitch). Ill ask the author!

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