Multi-material filament feeder/repurpose E1 stepper driver

Red Sand Robot

@jckray How much, roughly, did the NEMA 17 with the custom shaft? I have already begun printing the parts for your MMU system, so far so good!

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jckray

@red-sand-robot The MOQ was 10 units, It was several hundred dollars for the whole order. I'd be happy to sell you one, so you don't have to deal with all that. I'll get the motor listed in the parts section of our website, and post here when it is there.

jckray

@red-sand-robot The Nema 17 with 100mm shaft is available on our website now https://www.hydraresearch3d.com/parts/qmpid8sbp277kcd25a9wrngcqywaqr-j3j2n

fma

BTW, did you consider using PTFE tube with ID of 2.5mm, instead of 2mm? This should solve a lot of issue coming from bad tips.

I'm waiting for mine (seems to have been lost between UK and France )

jckray

@dc42

Okay, it's been a little while. I couldn't seem to get this to work properly. In particular, I could not figure out how to configure the E1 end stop for the dummy axis.

Also is there any chance that an extrude until filament sensor is triggered feature could be added?

I'm trying to have the filament sensor serve to purposes.

During unloading of the filament detect the end of the filament. During the ramming and unload from the nozzle I have noticed a little variance in the length. This is likely due to the filament "breaking" and leaving slightly different amounts of filament in the hot zone. If I can detect the end of the filament, I can the be sure that I have backed the filament out far enough to not interfere when the filament selector when it moves to the next filament, but not too far that it disengages with the drive gear.

I'm hoping I can make this work by disabling the filament runout external trigger at the beginning of my unload script so as not to get a false runout detected. Then I want to unload until the filament sensor is triggered so I know where the end of the filament is and then unload the last little bit to clear the filament from the filament selector.

Normal filament sensing. My idea here is to enable the filament runout external trigger and the end of each load script.

I know this may be a little confusing, hopeful I made myself clear.

dc42

@jckray said in Multi-material filament feeder/repurpose E1 stepper driver:

Okay, it's been a little while. I couldn't seem to get this to work properly. In particular, I could not figure out how to configure the E1 end stop for the dummy axis.

The first additional axis you create will use the E0 end stop input.

fma

@jckray, I'm also working on my filament multiplexer, and have similar issues...

@dc42, is E0 endstop assigned in all cases? Or only for dummy axis without associated driver? What if I define an axis on drive 6 (second drive of DueX); will it use its matching endstop (second on Duex5)?

fma

BTW, @jckray, I had an idea to use 2 switches acting as 1 endstop for loading/unloading, acting as an hysteresis. One upper switch is on the MMU (before the carriage in your case, or the passive splitter in my case), one lower switch is just above the extruder. They are wired as following:

loading sequence:

define endstop as NO
move until hit the endstop (using G1 U1000 F3000 S1): filament is now on the upper switch
redefine the endstop as NC
move again until hit endstop: filament is now on the lower switch
finish loading filament in the extruder (using both axis: G1 E150 U150 F180)

unloading sequence:

define endstop as NO
move until hit the endstop (using G1 E-1000 U-1000 F3000 S1): filament is now on the lower switch (out of extruder)
redefine the endstop as NC
move again until hit endstop: filament is now on the upper switch

Don't know if it helps in your case, but I will use this config.

dc42

@fma said in Multi-material filament feeder/repurpose E1 stepper driver:

@jckray, I'm also working on my filament multiplexer, and have similar issues...

@dc42, is E0 endstop assigned in all cases? Or only for dummy axis without associated driver? What if I define an axis on drive 6 (second drive of DueX); will it use its matching endstop (second on Duex5)?

Endstop inputs are allocated to axes in the order that you create them, whether you assign real drivers to those axes or not.

fma

It is not possible to re-allocate them?

dc42

@fma said in Multi-material filament feeder/repurpose E1 stepper driver:

It is not possible to re-allocate them?

Not currently, but it's planned for the future.

fma

Ok, thanks.