Change filaments on the fly

Gotcha, so you are using the USB. You can control the motors with the LCD, but not while printing. You can only adjust the settings and pause or stop the print while it's printing.

 

I just discovered that pausing the print does disable the steppers, accidentally moved Y axis half way through print, oops. pushed it roughly back into position and resumed, good enough.

Any way to modify the firmware so that the steppers aren't disabled during a pause, or to make the printer re-home x and y before resuming if the motors were moved?

 

you can use my program to modify gcode to tell the printer exactly what layer or layers you want to pause.
When paused, you can move extruder away by hand, change the filament and hit resume. It will go back to where it left off continuing print with new filament.
http://umforum.ultimaker.com/index.php?/topic/4185-tweak-at-layer-number-windows-application/
See it in action

 

Peter, Tony's program is great.

FYI - here is some G code that can be inserted at a layer change that will pause, beep, display a message, move Z up 10mm and X and Y to the left side out of the way. You can then change the filament and select resume on the LCD. It will home X and Y (not Z) and continue printing. The fact that it moves up and out of the way is nice because you can leave it and it will not ooze all over the print while it is paused.

; Filament Change Code for SD card Printing​

G91 ; Change to relative coordinates​

G1 Z10.000 F7200.000; Raise Z and arbitrary 10mm to get extruder out of the way​

G90 ; Go back to absolute coordinates​

M300 S300 P1000 ; Beep Sound​

M117 Change Filament! ; print message to LCD​

G1 X10.00 Y100.00 ; Get extruder away from print​

M25 ; pause the sd printing​

G28 X0 Y0 ; home X and Y to make sure you did not move the carriage​

My son and I taught a 3D printing class at his school and one of the 12 year old boys on his own initiative wrote a python script to insert this code at a selected height or layer. I'll post the script when I find it.
The class had fun making for example name plates with a black background and white letters.

 

Incredible Tony, thats so good it should be included by default!

I can't wait to get this thing dialed in so i can have that kinda fun!
Thanks for the info guys.

 

i use matter slice with the supplied matter control program. i hit pause and click X+ one time so it locks the steppers in place then when im done switching filaments i click X- one time to return to original position and click resume. u can move the extruder anywhere you want just keep track of how many times you clicked each axis move and do the opposite movements to return it to the original position. purge the new color with the filament with the extrude button. i also forgot to add that the stepper motors will auto unlock after exactly 60 seconds. so if you cant do what you need to do in that time. click the X+ button again anytime within the initial 60 seconds and it will add another 60 seconds. repeat that as needed to give your self enough time. just remember to add that movement to your back tracking to get back to the paused location.

 

I agree with skeeee above. I have it timed so i hit pause before the lettering layer starts; hit Z retract of 10 mm and then Retract of 100mm. When ready to insert the next color, I hit Z retract 1 more time to give me 60 seconds to thread the new color in place. I usually hit Extrude 10 mm to make sure everything is flowing OK. And then lower the Z back down 20 mm and resume.

 

I don't think it is all that hard. I made that square cube with the quartz crystals on top.
I made the cube with red ABS, then when it was at the crystal layer, I hit pause, moved the pressure roller off the filament and yanked it out. I then inserted the Transparent white ABS until it hit bottom. I then hit resume. No problem and the model turned out nice.
Frank