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Help getting filament shaped

Ok so now that I can successfully get the unit to push 4 colors to the extruder I need some help getting I’m the tips of the filament shaped to be able to retract or reload and not get stuck. if anyone has the unload settings in their direct drive setups would be great to see if you had to tweek the generated g code.

ender3 v2 microswiss direct drive

23 comments

23 Comments

Alfred Weippert

Dec 16, 2021

I've been able to get my Ender3 V2 with MicroSwiss direct drive to work with the following settings for tip formation and extraction.

; quickly retract the filament to shape it

G0 E-50 F10000

G0 E50 F2000

G0 E-50 F10000

G0 E-35 F50

What this does is extract the filament just into the plastic tube between the hotend and extruder at high speed then pushes it back down to the tip, repeats the high speed retraction then slowly retracts to cool out of the extruder gears.

I found the tubing from the extruder to the Y need to be at least 2.0mm IDO so as not to jam because the best shaped filament tip I've been able to get is 1.95mm in dia.

Bill

Dec 15, 2021

No... the positions are absolute... so it retracts fast to 50mm, then slowly an additional 30mm... (to the 80mm position) then it loads it all the way into the hot end (1mm from it's original position.) However, when you're saying it's not loading into the extruder... is your extruder starting up early enough? Is it spinning as the filament reaches it so that the 3D Chameleon and the extruder are pushing/pulling at the same time?

Michael Despault

Dec 15, 2021

Replying to

Thanks Bill, I overlooked the transitions between relative in absolute in the g-code. It makes much more sense to me now. I've also resolved the loading and unloading as well, though I still need to test it with an active hot-end. I removed the hot-end from the equation for testing while I refined my g-code, and was able to tune it so I could load and then unload one of the extruders 3 times in a row which is great progress. Next I'll continue working on the shaping and then it will only be a matter of making slight adjustments for the other 3 extruders

Michael Despault

Dec 15, 2021

I'm at this step right now as well. I'm pretty consistently able to load filament with any of the 4 gears, but the unloading is still problematic. Specifically, it tends to get stuck when the tip gets to the extruder (can't grip) and I'm guessing I need to shape the filament better.

I don't fully understand the generated g-code for unloading. ie:

G0 E-50 F2000 ; quickly retract the filament to shape it
G0 E-80 F600; slowly allow it to cool
 
G0 E1 F2000 ; blob elimination
 
G0 E-50 F2000 ; quickly retract the filament to shape it
G0 E-80 F600; slowly allow it to cool
 
G0 E1 F2000 ; blob elimination
G0 E-10 F2000 ; quickly retract the filament to shape it
G0 E1 F2000 ; quickly ram the filament to shape it
G0 E-10 F2000 ; quickly retract the filament to shape it
G0 E1 F2000 ; quickly ram the filament to shape it
 
G0 E-50 F2000 ; quickly retract the filament to shape it
G0 E-80 F100; slowly allow it to cool

My understanding of the above code is that it retracts the filament by 50mm quickly, then another 80mm slowly... then it pushes forward 1mm? to eliminate blobs? I don't yet understand why you would want to retract 50+80 and then only move it forward 1mm after it has cooled. It then does seem to repeat the same process but I guess the "G0 E1 F2000" throws me off since the filament would be only moving back such a small amount? I can fix the distances to be specific to my extruder/hot end distances (it's bowden tube, not direct drive) but what is the generator trying to accomplish so I can modify it?

Bill

Dec 08, 2021

It really doesn't matter where in the tube it retracts to as long as it's somewhere in a cool section. It's the total distance that really matters... and even that isn't so exacting... When it is retracted out of the extruder, we always run an extra 30mm back out to make sure it's fully expelled from it.

Bill

Dec 06, 2021

If you're using PrusaSlicer, I just use the built in settings for Ender 3... then reduce the retraction since you don't have a Bowden tube. Then our generated gcode gets added to the Tool Change gcode... set the printer configuration to 4 extruders and make sure you copy all the settings from Extruder 1 to the other 3 verbatim.

That should be all you need to worry about. The out of the box settings should be great.

Bill

Dec 15, 2021

Replying to

@brother_beams I never change those settings... our tool change gcode does everything that is needed without those being set. (If you do these, then you'll need to remove the same gcode from the Tool Change GCode.)

brother_beams

Dec 15, 2021

Replying to

@Bill ok so I need to get the single extruder mm settings out of the printer setup then my issue might go away

Bill

Dec 15, 2021

Replying to

@brother_beams So, the normal process I follow is to simply create a normal profile for my printer, then change it to have 4 extruders and copy all the settings from Extruder 1 to the other 3. I will then add the purge block, if necessary... but all the other settings, I leave alone. This way, you're starting with a known high quality profile. (As for PrusaSlicer's MMU settings, they're tailored more to their own MMU, whereas my GCode is more generic... it will pretty much work in any slicer that supports tool changes.) Now, with that said... I'm not saying to not use PrusaSlicer's MMU code... it might be fantastic and work perfectly, but we don't want to do double duty... so if their code can be used, then by all means... but you'll need to remove the corresponding code from mine. (Heck... it might be perfect for those users who already have a Prusa Mk3, for example... since I'm sure their testing on their hot end was way more extensive than mine... but other machines, I don't know.)

Bill

Dec 02, 2021

So... the temperature I'm referring to is the temperature you're changing the colors at, not what you're printing at... they can be two different temps. And yep... if you're using Cura, it could also be not taking into account the retraction distance on color change... for some reason, they don't include that in the current position... so it could be off by 10 or 12mm depending on that setting. As for the purge tower Cura, if you're talking about the hole in the center of the purge tower, that is normal... they have a very odd logic in their system and they don't even support the purge middle for previous layers... so a lot of the time, it'll just dump the purge into the middle without it attaching to anything. Personally, I only use PrusaSlicer for it now, as they really understand the details of MMU styles machines much better. Ultimaker sticks with just two colors for Cura, and really don't support it beyond that.

brother_beams

Dec 02, 2021

Replying to

@Bill ok I will attempt this weekend the prusa slicer getting a little burnt out on it messing with it before work and after work need a small break lol. But today I am getting closer to getting the tips shaped 3mm on the ramming is too much has some come out the nozzle so I’ll try 2 but that will have to wait. Thanks for the great info. I will update you in what happens this weekend with it.

brother_beams

Dec 04, 2021

Replying to

@Bill first attempt at the prusa slicer and it completely messed up my hotend so I’m not sure if I’m even going to keep trying it now. new issue is completely tear apart the microswiss hotend then reassemble and probably redo offsets

brother_beams

Dec 06, 2021

Replying to

@Bill I’m waiting a some new tube for the hotend should be here this week. As for prusa slicer there are a bunch of settings I’m not sure what all needs set. I saw one for unloading filament in a different tab not sure if that needs set also along with the prusa slicers generated g code from the website or not. I did change the gcode to match what I had for cura and got it in the color change tab of the slicer but not sure if there are more settings in prusa slicer that need changed to go along with it.

Bill

Dec 01, 2021

Yep... so, the GGode generator doesn't know about the specific design of your machine... which means it's not backing it out far enough at the start... we need to tune that so that when it retracts, it only goes all the way to the Capricorn tube. Then we can do the bounce from there to the tip. So, at the start of our code, it's only going to E-20... which isn't into that Capricorn yet... so we need to move it farther, maybe something like E-50 (but you'll need to measure where the optimal distance is). Then we need to make sure the bounce goes all the way to the tip... if it's actually needed. It should go to the tip as it is... but you might need to speed it up so it doesn't have a chance to melt again in the hot end. I've had customers report that they don't need to do anything at all with that extruder... just simply retract it into the Capricorn... let it cool... then retract it out.

Bill

brother_beams

Dec 01, 2021

Replying to

@Bill I messed with the retract distance and I think it’s close picture is what it ended up as but it did get stuck trying to retract so it still needs tweaking but better than what I was getting and I don’t have any smaller tubing I measured all the stuff I had which the id is all around 2mm even the Capricorn is 2mm

next question is I don’t think it’s starting with the first color more like the 4th and the gcode is correct in cura on the machine tool settings so when it prints the brim on the tower it doesn’t print the whole thing anymore I don’t want to open the test print as a new project again because it’s getting old having to copy and paste the generated gcode to each tool every single time and I don’t know how to keep it in there (thought I did and this is what is now happening) It Should be complete but it finished the brim like this

Bill

Dec 01, 2021

Replying to

@brother_beams Ok... two issues... #1 long thin round strings indicate the temperature is too high... but looking at it... did it actually ram into the nozzle to eliminate it, or was that just backed out? #2 - When you home it, it should always go to the 1st (top outside edge) extruder. Is that not what it's doing? What does your tool change gcode look like? When you start the job, it will not try to unload the last filament, because it assumes it is loaded to 1" before the Y adapter for each color... it will then switch to whatever color the slicer indicates it is moving to... so if it's starting color is 4, then that is where it will go to. Perhaps you can email me your gcode (for the file you're trying to print) so I can examine it. (You can also look into it... the 4 extruders will be indicated in the code by T0 - T3... and the LCD of your printer will also tell you which color it is switching to.)

brother_beams

Dec 02, 2021

Replying to

@Bill I have the temp at 215 for this PLA+ because on my other ender with the microswiss a temp tower looked really good there so might not be getting rammed into the nozzle again so it going from e-50 to e1 might need to go to e3 and see what happens when it rams back in.

For my second issue it goes to position one but then will go to 4 to print first. For some reason when I reloaded that test print that we download from the website with the 4 color squares and tried to use the settings I had saved and all the tool change g code so none of that wouldn’t disappear it started printing color 4 first and not completing the bottom on the purge tower so what I could do is copy all my tool change g codes to word reload the print as a new project and wipe out all my settings I adjusted and then edit everything again which is what I’ve done way too many times and tried To save my settings but apparently when that’s done it doesn’t print the same anymore as a completely new project. maybe it won’t matter I never looked at the print preview in cura to see if the center of the purge tower is even printed on in the upper layers for color changes so I’ll check that first.

Bill

Dec 01, 2021

So... I can see the blue Capricorn tube... have tried to adjust it so that it uses that spot for the cooling? That would be the ideal position for it to constrict it and shape the tip. Basically, alternate between that point (for cooling) and the nozzle for string elimination. What do your tips look like? Also, what changes have you made to the gcode?

brother_beams

Dec 01, 2021

Replying to

@Bill so what you are saying is adjust the retract mm on the unload g code from the websites generator to get the filament into the Capricorn tube so instead of the -10mm that’s there might have to move it more to get out of the heatbreak into the tube. The gcode generator is standard at -10 then rams back in to 1.

i cut the tips to get it ready to try and print again so I will have to run another test print to snap a picture but I will adjust the retract length for the filament shaping first then try it out