Z height with permanent printing plates

[alexbln01 2]

hello .... can you install a function where you can set the z height in the menu a bit higher? especially for permanent printing plates it would be interesting so you could use the automatic active bedivelierung again .... had such a function on sigma ... you have the bed automatically leveled and then you could put it a little higher in the menu, this was synonymous then saved as a new z worth ....

[yellowshark 153]

Hi, ok I think your solution is to use a Z-offset command. Printing uses absolute positioning and the z-offset command changes the physical position where the 0 absolute position is located. I think you are asking to bring your bed a bit closer to the nozzle when you say "a bit higher" ?

 

You need to put your G92 z-offset command into your Start G-code. You will find your Start G-code in the printer settings. Go to Menu item Settings, then select Printer, then select Manage Printers. A list of printers will be displayed in a dialogue box, select your printer from the list displayed and then select the "Machine Settings" tab on the right-hand side.

 

You will then get a dialogue box showing details of your printer and on the left hand side a box called Start g-code. This is where you enter your command. You need to do your positioning in relative mode, i.e. relative to the z axis position when this command is processed. So

 

G91              ;set relative positioning

G92 Z+0.050       ;set z-offset to move bed closer to nozzle by 50 microns

G90              ;return to absolute positioning

 

This assumes you want the move to be 50 microns

 

Oh, if the dialogue box already has g-code in the Start gcode box then best if you post it here, before doing anything. Especially if it has G90,G91 or G92 codes

 

IMPORTANT: This is very important. I think G92 Z0.050 moves the bed away from the nozzle and G92 Z+0.050 moves the bed towards the nozzle, but I am not certain. I have only used the G92 command withabsolute positioning and the Reprap paper on commands I am looking at, does not comment on negative vs. positive positioning when using relative positioned commands.

 

Hopefully someone on the Forum can give a definitive answer. 

 

Anyway I will advise you to test this. 

I assume your gap between the bed and nozzle is 0.1mm and so I chose 0.050mm as being midway. 

After the G90 command enter the command for an emergency stop -  M112

This works with most firmwares but not Sprinter; I do not know what firmware you have.

 

Before running the g-code, slide a piece paper between the bed and the nozzle, you should feel some slight friction.

Run the gcode and check again; you should feel an increased friction; if you feel nothing then the codes are the wrong away around - the bed has moved away from the nozzle.

 

And finally change the 0.050 measurement to what you want.

 

 

 

    

Edited January 22, 2018 by yellowshark