Makerbot Replicator Mini and z-offset

[MungoBBQ]

Hello, I am printing using the Makerbot Desktop, but want to feed it .makerbot files from Simplify3D to have more control. My first problem is that the z-offset needs to be set. in Makerbot Desktop I've got the z-offset set to -0,20mm and that seems to work great for printing from there.

In Simplify3D, I've attempted to set the same z-offset under the "G-Code" tab, in the "G-Code offsets" values, changing the Z-Axis to "-0,20mm" and even trying higher values (-0,40mm) but nothing seems to work - when I print the sliced file using Makerbot Desktop the first layer is still dropped in the air.

Am I changing the wrong number, or in the wrong place?

[JoeJ]

I thought that you set the Z-offset in the firmware, not in the software...

[MungoBBQ]

Well, no? The offset is set in the Makerbot Desktop but the setting does not seem to follow when I choose "print from file".

[M600]

The Z offset setting sit in the firmware as far as I know.

Regarding your issue, i'm currently in the same process with my Mini too (Trying to get printing without raft at 0.1mm). Fact is that I was having the same issue as you with the first layer being printed mid-air.

I discovered that when the Starting G-Code was done, the wipe movement wouldn't drop the nozzle back down and therefore screw the first layer so I added an additional command that would extrude a few millimeter and this would make the head drop down afterward.

Here is my Starting g-code so far (additional command and Z height tweaking):

Code: Select all

M104 S[extruder0_temperature] T0
M126 S[fan_speed_pwm]
G1 X-60 Y-50 Z1 F9000 ; move to wait position off table
G1 Z0.1 ; position nozzle
G1 E10 F300 ; purge nozzle
G1 X-45 Y-50 Z0.2 E3 ; slow wipe and 3mm extrusion to drop the nozzle

Reset the offset back to zero, update your starting code and retry.

So far, it came out perfect on mine.

Hope it will be usefull.

[MungoBBQ]

Thanks! I will try this out. I wonder how the raft is printed OK while the nozzle is too high in the air during first layer without raft.

[M600]

Be aware that my bed is glass so even if the nozzle touch the bed, it doesn't damage it.

With the crap stock bed, you might damage it. It would be wise to adjust the Z height on the G-code and start with an higher value that would work for you (highlighted in red):


G1 X-60 Y-50 Z1 F9000 ; move to wait position off table
G1 Z0.1 ; position nozzle
G1 E10 F300 ; purge nozzle
G1 X-45 Y-50 Z0.2 E3 ; slow wipe and 3mm extrusion to drop the nozzle

[MungoBBQ]

Yep. This worked like a charm, thank you so much for the help!