Filament change at layer

[bigone5500 0]

I am trying to change filament at layer x and am using modify g code. I use pause at height and change it to layer number. I then set all other parameters as needed. My print head moves to the prescribed coords and then shortly after it resumes printing. Is it best to use the filament change script? What is the best way?

[bigone5500 0]

I just gave the filament change script a try and it didn't even pause.

[Thegladster 2]

Watch this video by CHEP-

 

[bigone5500 0]

1 hour ago, Thegladster said:

Watch this video by CHEP-

 

That's the exact video I watched. I have done exactly what he does and my printer does all but one thing...pause. It will retract the filament, lower the print a bit, then go to the coordinates I put in. Then about 2 seconds later it automatically resumes printing. I don't know what could cause that.

[Thegladster 2]

So in the video, he says that if you touch the control panel, in any way, move it left, or press the button down, it will start automatically. If you are trying to change filament, 3D print the wheel he uses and connect it to the stepper motor. If you try to move the extruder using the control panel, it won't work.

[bigone5500 0]

I am in the process of doing a test print, a 10x10x2 square. I have it set to pause at layer 5 and cool down to 100c. I will post back with my findings. I will also be extra cautious not to touch the control panel.

[bigone5500 0]

Ok...so I sat there and watched it. It did just as it had before. Maybe I will tell it to also do a filament change...???

[bigone5500 0]

Adding filament change script after pause at height did not work. The machine paused for 2 seconds and resumed automatically.

Edited May 3, 2020 by bigone5500

[tinkergnome 927]

19 hours ago, bigone5500 said:

My print head moves to the prescribed coords and then shortly after it resumes printing. Is it best to use the filament change script? What is the best way?

 

It highly depends on the (kind of) firmware the printer uses. "Pause at height" uses the command "M0" to do the actual pause and "Filament Change" inserts "M600".

If the printer does not support these commands it will ignore them (in the best case) or it will perform something completely different (in the worst case).

There's no standard for gcodes, but if the firmware type is known, one can at least make well-founded assumptions. Sometimes it even depends on the firmware version or how it is configured.

 

There are additional pause scripts for Repetier and RepRap firmware which are using different commands. There are printers with (in-build) menu-driven functions to assist filament change during pause, while others don't allow it, and so on.

 

Your chances of qualified answers are much higher, if you tell us the printer model and/or the installed firmware(-version).

If you use a printing host like Repetier or Octoprint another layer of complexity is added. So this would be interesting as well.

 

Good luck!

 

[bigone5500 0]

I'm using an Ender 5. I don't know how to get the firmware version though. I bought it roughly a year ago and haven't updated it.

Edited May 3, 2020 by bigone5500

[Thegladster 2]

Try changing 'Extrude Amount'. If it is low, one it finishes extruding, it starts moving.

Set 'Disarm Timeout' to 0.

[Lordpaul 1]

In Cura 4.7 Will Setting the 'Disarm Timeout' to 0 Lock the steppers until you're ready to continue? Or  Free them up?   They need to be locked long enough to change the filament.  I've used pause at height in earlier Cura but 'Disarm Timeout' setting was not available.

[GregValiant 1,351]

The Disarm Timeout can be set to 1800 seconds max (30 min - that's hard coded in the Plugin).  You could go into the Gcode and change it to 14400 (3hrs) which is the max that my printer will accept.  It's a matter for the firmware to decide.  On an Ender 3pro the disarm timeout cannot be shutoff.

The Marlin firmware on my Ender 3pro will accept either the M0 line or an M25 line to pause.  M25 requires that an M24 be sent to restart.  The M0 requires a button click on the LCD.  I usually don't use the "Extrusion after pause" but rather just hand force the filament through the hot end until the color changes, hang on to the end with tweezers, and click the button.

The trailer is a coaster holder for the wife.  8 Pause at Heights.  The transitions between layers were made in the inner infill so the transitions were dead nuts.

 

Edited September 1, 2020 by GregValiant

[Lordpaul 1]

Thanks Greg for all the useful info.  I've used the pause at height to make name plates and it worked well in the older Cura.  I have a highly modified Creality CR10 S4.  I'm still confused as to the Disarm label does it lock the steppers for the time set 0 to 1800 seconds entered?  Or  does it disengage the steppers?  I have a 3.5 day print job pending and I want to make sure the steppers hold at the pause so the print continues the layer where it left off. 

Thanks again!

[GregValiant 1,351]

It locks the steppers for the time you input (in seconds).

The Gcode is M18 (or M84) and sets the "Inactivity Timeout" of the steppers so what that line of the Pause at Height does is set a timer.  When the timer runs out the steppers disable and the axis lose their position.  If no time is specified the steppers disable immediately.  M17 disables the steppers as well.  The default stepper timeout for my Ender is 120 seconds.  The printer will go back to 120 seconds on any reset (power off or external reset via USB).  It's hard coded in the firmware so we are unable to permanently set the timeout to say 3600 seconds.

[Lordpaul 1]

Greg, Thanks a bunch for the clarification! I just wanted to be sure of my understanding so I didn't ruin prints. 

Attached is my first successful 2 color test print.  I've had some failures with text plates that just paused for a second and kept printing. O Well got it now!

[GregValiant 1,351]

Nice.  I've found that the bonding between layers at the color change is pretty close to the regular bonding between layers.

 

You can open the ...Plugins/PostProcessingPlugin/Scripts/PauseAtHeight.py file in a text editor and make changes so you don't have to enter your values every time.  The section starts in about line 61 in the file.  Save the file and then re-start Cura.

Here is the relevant section that I altered (so I can go fishing for a couple of hours without being nervous about the print).

Make a back-up before you start altering anything.

 

 "disarm_timeout":
                {
                    "label": "Disarm timeout",
                    "description": "After this time steppers are going to disarm (meaning that they can easily lose their positions). Set this to 0 if you don't want to set any duration.",
                    "type": "int",
                    "value": "14400",
                    "minimum_value": "0",
                    "minimum_value_warning": "0",
                    "maximum_value_warning": "14400",
                    "unit": "s",
                    "default_value": "14400"
                },

I also made a change to the default value of "StandBy_Temperature".  Leaving the steppers with current to them for hours without moving probably isn't the best thing, but generally they aren't on for hours.  An M84 S120 in the "Ending Gcode" in the machine settings in Cura is a good idea.

[Lordpaul 1]

Greg,

Sorry to bother you again I updated to 4.7.1 and tried a Pause at height test print again.  It never paused at height just kept on printing.  So I opened my Gcode file and searched for "M0, Pause, Change-Color" and they came up as not found.  I re-sliced and searched again with the same results??  I can only conclude the Pause at height Script is not working.  Oh and I have not edited the script as you suggested.

 

I re-sliced with the change filament script and searched my Gcode for M600 and found the line --M600 E30.00 L50.00 X10.00 Y10.00 ; Generated by FilamentChange plugin.  It printed but with a Blob on the tail.

 

Attached are the 2 prints.  The first with the Pause at Height failure and the second with the Change Filament script.

 

Thanks again.

Paul

Edited September 12, 2020 by Lordpaul

[GregValiant 1,351]

I'm still using the 4.7 beta and I won't be moving on until the furor over 4.7.1 settles down.

I think you should leave an "issue" on the GitHub site regarding the new Pause at Height problem.  Not altering the Gcode file means it isn't working at all.

If you still have the 4.6.x version installed you could try copying PauseAtHeight.py from the scripts folder there, into the scripts folder in 4.7.1.  If there is an issue with the new 4.7.1 PauseAtHeight (I should think it would be the same) it may resolve itself.

 

Maybe one of the Cura team folks will drop by and address this.   Without 4.7.1 I'm flying in the dark.

[Lordpaul 1]

I tried the old script from both 4.6 and 4.5 and  got the same results.  Absolutely no pause code in the gcode file. Oh and I removed and reinstalled Cura still no pause.

 

Bug reported and they closed it an hour ago with out a fix??

https://github.com/Ultimaker/Cura/issues/8373

 

 

[GregValiant 1,351]

I don't know how he could decide that it's "not an issue anymore" after only 12 hours and with no explanation.

Have you tried using the Pause at Height with the earlier versions of Cura?

[Lordpaul 1]

Greg,

I've been working on this all Night and Day.  I  did try the old script from both 4.6 and 4.5 and  got the same results. So I uninstalled Cura deleted and folders or files left behind then reinstalled it still not working. I went to my laptop installed 4.5, Same results.  Went to an old PC with Cura 3.6 it worked!!  I went back to my main PC and reinstalled it over the top of the 4.7.1 install and WOW all is working now.  Don't know what fixed it but it works so thanks again for all your help.

 

Paul

[GregValiant 1,351]

Your welcome.

I hate it when something fixes itself for no apparent reason.  If the same problem recurs I'm just as clueless as the first time it happened.

[Lordpaul 1]

Hi Greg,

It seems there is another issue that I've discovered with the Post Processing Pause at Height Script.  I've had 3 failures in my last 4 practice attempts.  My printer has a Filament Brake Sensor.  And I've discovered when I go to change the filament at the pause it seemed to work for only a layer then it stops extruding but the head is still moving.  It turns out that when you pull out the filament it stops the bed from heating, which stops the extruder from heating also??? 

 

So I had a second Filament Sensor, I plugged it in and stuck a piece of filament in so it didn't trip when I swapped out the filament and that works, L0L. 

 

I thought this could help any users out there that maybe having Issues whit Post Processing Pause at Height feature.

 

Paul

[tcc1313 0]

@Lordpaul: I’m having the same issue with 4.7.1.  What did you do exactly to get the pause at height feature working again?