Marlin: SINGLENOZZLE: EXTRUDERS versus HOTENDS

[MoonshineSG]

The pull request #3895 from thinkyhead/rc_singlenozzle_part_2 to modify extruders vs hotends to support single nozzle added a ton of changes. Previously I was able to create a custom M890 to allow me to change between Single to Dual nozzle as and when I needed. With the new changes, that is not possible (easily)
Am I the only one that would swap between single and dual nozzle often enough to be annoyed by the need to flash a new firmware every time ?

Can the switch between single/multiple be done using a M code ?

Send: M890 N1
Recv: //action:tool 0 cyclops
Recv:  9.00,0.00 9.00,0.00
Recv: ok

_action:tool allows Octoprint to display the current selection, and even change it when a GCODE file is loaded, base on the slicing profile used_

Send: M890 N2
Recv: //action:tool 0 chimera
Recv:  0.00,0.00 18.00,0.00
Recv: ok

Send: T1
Recv: //action:tool 1 chimera
Recv:  0.00,0.00 18.00,0.00
Recv: ok

[thinkyhead]

@MoonshineSG What about the recent changes is getting in your way? As long as SINGLENOZZLE is disabled, HOTENDS is the same as EXTRUDERS.

If you're able to rebase your custom Marlin onto RCBugFix at a point just prior to the recent SINGLENOZZLE changes, please make a branch out of that. Starting there I'm sure we can figure out a way to adapt your code and M890 to the recent changes.

[MoonshineSG]

With the changes I made after you posted the initial SINGLENOZZLE codes, I leave the SINGLENOZZLE enabled and using M890 N(1|2) i change the nozzle X offsets 9,9 or 18 (in my case) and add a single bool variable singlenozzle which then is used in Temperature::get_pid_output;

      bool nozzle_test = (e == active_extruder);
      uint8_t nozzle_extruder = e;
      int cterm_index = e;
[...]
        if (single_nozzle) {
            nozzle_test = true;
            nozzle_extruder = active_extruder;
            cterm_index = 0;
        }

With the new changes I see alot of checks #if ENABLED(SINGLENOZZLE) and I am sure that not all can be simply replaced with a bool variable check...

[MoonshineSG]

@thinkyhead does this helps ?
https://github.com/MoonshineSG/Marlin/commits/single_nozzle_M890

[thinkyhead]

the initial SINGLENOZZLE codes

Well of course that code was totally incomplete. So, the main difference that HOTENDS introduces is that temperature checks only apply to the one nozzle. But EXTRUDERS still applies to the E steppers. The conditions based on ENABLED(SINGLENOZZLE) are not that many. Almost all changes pertain to the use of HOTENDS where EXTRUDERS used to apply.

does this helps ?

It should! From that commit I can perhaps figure out how to adapt M890 to this new environment. I'll mess with it shortly…

[thinkyhead]

Ok, so… How are your steppers and extruders related? Or, what are the two setups that you're switching between, exactly?

With SINGLENOZZLE the main thing is that there is only a single nozzle, but multiple steppers are connected to that one nozzle. When you switch "extruders" you are still using the same heaters and thermistors, but a different (single) E stepper motor.

With multiple extruders (EXTRUDERS >= 2), there's more than one nozzle on the same carriage, each with its own (single) E stepper. Of course, this is entirely incompatible with the SINGLENOZZLE feature as we have implemented it (based on MarlinKimbra), because it needs to manage more than one heater/thermistor.

So what you need is a new feature, essentially, that allows you to switch your particular setup. It can mimic SINGLENOZZLE but it can't rely on SINGLENOZZLE.

[MoonshineSG]

There's nothing really special about my setup. Imagine a dual extruder prusa with e3d chimera hotend.
This setup is used when printing 2 materials (PLA/PVA mostly). This of course has 2 extruders, 2 heaters, 2 thermistors and 2 nozzles.

When I want to print dual colours I take out the heat breakers & 2 heater blocks and replace them with the 2 in 1 out E3D cyclops heater block. That has 2 extruders, 1 heater, 1 thermistor and one nozzle

Currently when I use cyclops I add an additional thermistor to the empty slot so Marlin doesn't throw a thermal error.

unless you have 2 separate printers, I am very sure this is common setup

M890 allow to change the offset between --v--v-- and ----v---- nozzles.

[thinkyhead]

So the two configurations you need to be able to swap:

• Chimera: 2 stepper, 2 heater/thermistor/nozzle
• Cyclops: 2 stepper, 1 heater/thermistor/nozzle (i.e., "single nozzle")

Are you using the same set of 2 steppers, or 4 steppers total?

I'm not sure that we can (or want to) create a general feature to support changing setups in this manner (because then we need to support many other kinds of setups). But if you were able to do it with the incomplete SINGLENOZZLE feature, then I'm certain you could make this as a custom feature for yourself. Basically, by imitating that first set of SINGLENOZZLE changes, but giving your custom setting a different name.

[MoonshineSG]

Using the same set of 2 steppers (left-right). Basically I just change the heater block (with thermistors).

Ah... so I take latest marlin with the new ("complicated") SINGLE NOZZLE support (so I can stay up to date with code changes) and set it to 2 extruders, 2 hotends, plus my own existing changes but renamed to CHIMERA_CYCLOPS_AWSOME_SETUP ?

that might work...

what features from the complete SINGLENOZZLE would I be missing ?

[thinkyhead]

I'll see if I can illustrate what I mean, using your branch, reworking it so it doesn't collide with SINGLENOZZLE anyplace.

("complicated")

Well the idea of SINGLENOZZLE (which has been in MarlinKimbra and some other forks for well over a year) was to be able to simply set the single option, then your multi-extruder would work with no other rigamarole required. In other words, it was designed to be "simple."

[thinkyhead]

what features from the complete SINGLENOZZLE would I be missing?

It depends on how much of SINGLENOZZLE you decide to borrow. But basically, if you look at all the places in the current code where EXTRUDERS is still being used (rather than HOTENDS) you can see where the number of extruder steppers still applies. And every place where HOTENDS is used, you will see where only the number of hotends matters.

For your customization, you don't want the "feature" of SINGLENOZZLE where it always assumes you only have a single heater. You want to be able to turn that on and off with a flag.

Basically, if you do a global search on SINGLENOZZLE, EXTRUDERS, and HOTENDS you will find all the places where behavior _may_ need to be tuned. And you can decide in each instance whether a change (checking your single_nozzle flag, for example) is needed.

[MoonshineSG]

I did that... thats why I called it "complicated" :D But I guess I can give it another try.

For now I will go with the renamed simple version (probably find a better name than CHIMERA_CYCLOPS_AWSOME_SETUP ) on top of the latest RCBugFix

I'll shout for help if need be...

[thinkyhead]

Sounds good. I will be working in parallel on this also, because it intrigues me to see what is required.

[thinkyhead]

Integrating your changes into RCBugFix… https://github.com/thinkyhead/Marlin/tree/rc_singlenozzle_M890
…without any extra work to check on other places where single_nozzle might come into play.

[MoonshineSG]

:D You're fast. I was only half way there...

I'll port the changes to my repo and run some tests.

[thinkyhead]

I've just cleaned it up a bit. I will probably leave it where it's at for now…

[MoonshineSG]

No worries, I can take over from here. The idea of having a separate setting for this case was what saved me. I don't need to care about extruder/hotend code changes....
Thanks again.

[MoonshineSG]

I cleaned up my code, added some extra checks and seams like everything is ok. I managed to do an update to the latest RCBugFix version without conflicts, so that's good.

https://github.com/MoonshineSG/Marlin/commit/8843e978ed56bb4c4e067e6b905fe7e707b90c78

(I managed to mess my github and now by default it compares with RC instead of RCBugFix... No idea how to revert that... grrrr..... )

[thinkyhead]

mess my github and now by default it compares with RC instead of RCBugFix

That's how it has been for a long while. In fact, one of the main reasons I made the mfpr shell script.

[MoonshineSG]

I am pretty sure previously it was reporting "This branch is X commits ahead, Y commits behind MarlinFirmware:RCBugFix".

[thinkyhead]

This branch is X commits ahead, Y commits behind MarlinFirmware:RCBugFix

When? Where? How? Why? The default branch is RC and when you do a compare (using the button on your Github page), it's supposed to compare to the _default_ branch. For me it has worked this way for a long, long time, taking an extra step to get it to compare to RCBugFix.

[MoonshineSG]

here... But I am an idiot!!! I renamed my own branch prusa_i3 so now it compares to the default branch in MarlinFirmware... Previously _my_ branch was called RCBugFix as well. Github is smart. I am not.

Sorry for the confusion. :D

[jbrazio]

@MoonshineSG Can we close this issue ?

[MoonshineSG]

yes. it's all good. Thanks.

[MoonshineSG]

@thinkyhead I was away for a while and now I looked at the changes and noticed "SWITCHING_EXTRUDER" and "MIXING_EXTRUDER" on top of "SINGLENOZZLE"...

Would this conflict or replace the functionality of my implementation of "SWAPPABLE_EXTRUDER" ?

[thinkyhead]

The new options try to compartmentalize their behavior, so they shouldn't get too much in the way. The main changes they apply are in the stepper_indirection.h file, since they each affect how steppers behave.

• SWITCHING_EXTRUDER drives a single stepper motor that reverses direction for T1.
• MIXING_EXTRUDER moves 2 or more steppers proportionally, with enable/direction applying to all.

This block in Conditionals_LCD.h is the part that you need to pay attention to:

/**
 * Extruders have some combination of stepper motors and hotends
 * so we separate these concepts into the defines:
 *
 *  EXTRUDERS    - Number of Selectable Tools
 *  HOTENDS      - Number of hotends, whether connected or separate
 *  E_STEPPERS   - Number of actual E stepper motors
 *  TOOL_E_INDEX - Index to use when getting/setting the tool state
 *  
 */
#if ENABLED(SINGLENOZZLE)             // One hotend, multi-extruder
  #define HOTENDS      1
  #define E_STEPPERS   EXTRUDERS
  #define E_MANUAL     EXTRUDERS
  #define TOOL_E_INDEX current_block->active_extruder
  #undef TEMP_SENSOR_1_AS_REDUNDANT
  #undef HOTEND_OFFSET_X
  #undef HOTEND_OFFSET_Y
#elif ENABLED(SWITCHING_EXTRUDER)     // One E stepper, unified E axis, two hotends
  #define HOTENDS      EXTRUDERS
  #define E_STEPPERS   1
  #define E_MANUAL     1
  #define TOOL_E_INDEX 0
  #ifndef HOTEND_OFFSET_Z
    #define HOTEND_OFFSET_Z { 0 }
  #endif
#elif ENABLED(MIXING_EXTRUDER)        // Multi-stepper, unified E axis, one hotend
  #define HOTENDS      1
  #define E_STEPPERS   MIXING_STEPPERS
  #define E_MANUAL     1
  #define TOOL_E_INDEX 0
#else                                 // One stepper, E axis, and hotend per tool
  #define HOTENDS      EXTRUDERS
  #define E_STEPPERS   EXTRUDERS
  #define E_MANUAL     EXTRUDERS
  #define TOOL_E_INDEX current_block->active_extruder
#endif

For your feature, just add #elif SWAPPABLE_EXTRUDER with the values that apply to your feature. Then peek at the places where the new E_STEPPERS and E_MANUAL values are utilized. You probably don't need to make very many changes, compared to previously.

[MoonshineSG]

I did have an attempt to introduce my own SWAPPABLE, but al the above cases the HOTENDS is defined at compile time, while mine would change at run time. So I'm going with the easy way of having 2 compiled firmwares and burn them as and when I change the hotend... Not ideal, but workable for now...

[thinkyhead]

the above cases the HOTENDS is defined at compile time

True, but this is actually not too hard to work around. You can add your own (yet another) macro, define it as #define ACTIVE_HOTENDS hotends_count for SWAPPABLE_EXTRUDER but as #define ACTIVE_HOTENDS HOTENDS for others, and then replace HOTENDS with ACTIVE_HOTENDS throughout the code, in just the places where your hotends_count variable should apply. And, boom, you now have a variable taking over HOTENDS just for your case.

[boelle]

@thinkyhead so we can close this one again??