Raising the Extruder  

Eminent Member

When you want/need to inspect, clean, or change the extruder, is there a way make the printer do it?  I know it can be done manually, but I am guessing it can be done with a console command.  Which raises the question: how do I get to the console's main menu?

Thanks,  Bob

Posted : 23/08/2020 9:33 pm
Veteran Member Moderator

Connect Prontaprint then send 

G1 Z210    But if your Extruder is already partially raised, the above command will cause the X axis to rattle against the top of the Z axis... 

on the command line

May be better to send commands to heat the hot end, then home the hot end, then raise to X 125, Y0 Z210... 

Move the bed back, centre the Extruder on X axis, and raise extruder to top... 

this would be better as a custom Gcode...  that you can call anytime that you want it!

regards Joan


I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 23/08/2020 10:20 pm
Prominent Member

Here's what I've been using.  I was just manually  punching and dialing in a higher Z distance to inspect and brush off the nozzle but this is very simple and I have it saved as RAISE.gcode on both of the cards I use with the printer.

It's basically some of the start-up and shut-down code from one of the .gcode files with one X/Y/Z line added.  It gets things to a known state and warms the nozzle up to a temperature enough to melt any ooze hanging from the nozzle and any boogers that are sticking on or around the nozzle.  It then raises things and gets the heatbed out of the way so flakes of crud that are brushed off don't fall on the heatbed and get trapped between the heatbed and the build plate.

Yes, I'm sure much of this could be deleted or commented out.

It turns the motors off so the plate can be manually moved forward if needed to get the next print going.

M201 X1000 Y1000 Z200 E5000 ; sets maximum accelerations, mm/sec^2
M203 X200 Y200 Z12 E120 ; sets maximum feedrates, mm/sec
M204 P1250 R1250 T1250 ; sets acceleration (P, T) and retract acceleration (R), mm/sec^2
M205 X8.00 Y8.00 Z0.40 E4.50 ; sets the jerk limits, mm/sec
M205 S0 T0 ; sets the minimum extruding and travel feed rate, mm/sec
;; M862.3 P "MK3SMMU2S" ; printer model check
M862.1 P0.4 ; nozzle diameter check
;; M115 U3.9.0 ; tell printer latest fw version
G90 ; use absolute coordinates
M83 ; extruder relative mode
M104 S215 ; set extruder temp
;; M109 S215 ; wait for extruder temp
G28 W ; home all without mesh bed level
G1 X50.0 Y0.0 Z70.0
M84 ; disable motors

This post was modified 2 months ago 2 times by jsw
Posted : 23/08/2020 11:39 pm
Honorable Member

The trick to being sure that you G1 actually moves the z axis up is to go into relative mode, move a small amount and then go back to absolute.

The default end GCode for MK3s in PrusaSlicer shows some clever math (well too clever for me) to ensure that you not only go up but also you do not hit the top.

Posted : 24/08/2020 2:32 pm
Illustrious Member

If you just want to move the nozzle up quickly, press & hold the front knob. The printer will beep and you'll be able to adjust Z height. Not sure how using gcode can be any easier than that. 

As @towelrg notes, you want to go into relative mode (M83) before doing moves. This is very important to avoid moving the nozzle into your print. In relative mode, negative numbers move down, positive numbers move up.

The nifty gcode PrusaSlicer generates is print-specific (calculates move based on max Z position), so can't be used universally to avoid making rude noises.

Also be aware that the printer has no way of knowing where it is after a reset until it has been homed. Don't count on moving to absolute positions without homing. And homing moves the nozzle to XYZ=0, so can wreck a print on the bed and really screw up your leveling.

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 24/08/2020 3:42 pm
Eminent Member

bobstro: "If you just want to move the nozzle up quickly, press & hold the front knob. The printer will beep and you'll be able to adjust Z height"

PERFECT!  I appreciate all of the replies but before I get into gcode I need more schooling in Fusion 360 and PrusaSlicer and how to choose the right filament for a project and probably several other things.  Geez, I was looking for a really interesting hobby and I seem to find myself in a PhD program!

Thanks,  Bob

Posted : 25/08/2020 6:59 pm
mike.h26 liked
New Member


Great comment Bob - I feel the exact same way on this stuff.  I’m finally signed up for a class at the local community college to learn CAD!

Posted : 26/08/2020 3:11 am

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