start.gcode for UM2 and Cura 14.07

[Nicolinux 288]

Hi,

I'd like to use OctoPrint and occasionally Simplify3D so I have to use the normal gcode flavor. Right now the startup procedure on the UM2 does not reflect the start.gcode in Cura 14.07 (or I don't understand gcode all too well):

;Sliced at: {day} {date} {time}

;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}

;Print time: {print_time}

;Filament used: {filament_amount}m {filament_weight}g

;Filament cost: {filament_cost}

;M190 S{print_bed_temperature} ;Uncomment to add your own bed temperature line

;M109 S{print_temperature} ;Uncomment to add your own temperature line

G21        ;metric values

G90        ;absolute positioning

M82        ;set extruder to absolute mode

M107       ;start with the fan off

G28 X0 Y0  ;move X/Y to min endstops

G28 Z0     ;move Z to min endstops

G1 Z15.0 F{travel_speed} ;move the platform down 15mm

G92 E0                  ;zero the extruded length

G1 F200 E3              ;extrude 3mm of feed stock

G92 E0                  ;zero the extruded length again

G1 F{travel_speed}

;Put printing message on LCD screen

M117 Printing...

"G28 Z0" does not look to me that it is what it really happens. The heated bed does not move up to Z0 (or else it would touch the nozzle). It moves up about 15mm beneath the nozzle and then filament is extruded a bit.

But maybe I don't get the meaning of "min endstop". Max endstop for the heated bed would be down where the microswitch resides and triggers - so min endstop must be at the top, beneath the nozzle.

Also filament extrusion occurs in two steps (different sounds and speeds), but here in the start.gcode there is only one filament extrusion statement.

So what would the start.gcode for the actual UM2 firmware (14.6.02 I think for Cura 14.07) look like?

Thanks

 

[Daid 306]

The comment that I put there is actually wrong.

G28 Z0 means "home Z", after that the UM Original had the nozzle on the bed, but on the UM2 the bed is at the bottom then.

The UM2 does not really have "start gcode", the procedure to start a print is coded and does a few things special.

But it comes down to:

G28

G1 F12000 X5 Y10

M190 S{bed_temperature}

M109 S{print_temperature}

G92 E-???

G1 F??? E0

G92 E-???

G1 F??? E0

 

Which is, home, put nozzle above bed, heat-up, reverse end-of-print retraction, slowly prime nozzle.

 

[Nicolinux 288]

Thanks Daid. I will take it and hopefully substitute sensible values for the missing bits.

 

[Nicolinux 288]

Now that I think of it, you also do some sneaky things with the hotend temperature. You don't heat it up right away but wait for the heated bed to reach a % of the target temperature I guess. Is this possible to be expressed in gcode?

 

[Daid 306]

Now that I think of it, you also do some sneaky things with the hotend temperature. You don't heat it up right away but wait for the heated bed to reach a % of the target temperature I guess. Is this possible to be expressed in gcode?

 

Not really, that's why in the example I gave I heat up the bed first and then the hotend.

 

[Dim3nsioneer 557]

Assuming TBed=60, Tnozzle=210;

What about:

M190 S45

M104 S210

M190 S60

M109 S210

 

[Daid 306]

could work, but could also stall for a while at the first M190 as it might wait for the bed to stabalize.

 

[Nicolinux 288]

Just as reference for others - here is another thread with related info:

 

• http://umforum.ultimaker.com/index.php?/topic/6885-kisslicer-1407/
  

 

[bob-hepple 59]

Daid

im struggling with s3d in your code does lines

G92 E-???

G1 F??? E0

G92 E-???

G1 F??? E0

 

prime the extruder

 

I read a thread and increased the std setting setting to 20mm but when the machine is just started 1st print this doesn't work unless I move material in the console on the machine (UM2)

 

im struggling with the setup the bed goes down as the the extruder drops it prime and then theres a mess and the print starts a mess

 

any help appreciated

 

bob

 

[Daid 306]

The ??? have to be replaced by actual values, which I do not know out of my head.