XYZ Davinci 1.0a + repetier 0.92 z-offset problem

[dr-error]

Hi Doodle3D team,
I have some news on the XYZ Davinci 1.0a which was standing in your studio for the last half year or so ;) Today I have flashed it with repetier 0.92 firmware. After that it was easy to get Doodle3d going. Since Doodle uses the Ultimaker as default printer I found that the Ultimaker startcode is doing a proper job controlling the printer.
For now there is one issue though, the Z is slightly off when starting a print. I need some help getting the Z-offset inside the startcode. The bed starts proximally .5 mm to heigh.
I have very little G-code experience. Do you have any idea how to mod the startcode to get this offset right?
Thanks for your help!
Marco

[companje]

Hi Marco, great to hear you got the XYZ Davinci 1.0a to print from Doodle3D by updating the firmware of the printer to Repetier firmware!

It could be that a G92 Z5 after the G28 in your start g-code could help but I'm not sure. Just try it out and let us know if get's better, worse or the same.

You write it's 0.5 mm off. Is it really just half a mm or do you mean 0.5 cm?

[dr-error]

Thx, I'll try that. It's just half a mm, might be a bit more. The filament is dragged around by the head and the head forces the bed down. Is Z5 the correct for 5mm?

[companje]

In that case I think you should try G92 Z0.5 or G92 Z-0.5.

[dr-error]

This does not fix the issue. The LCD shows that the z-axis value has changed but the bed is at exact the same place on start. Must be some other mod to fix this.

[peteruithoven]

@dr-error When printing a file from SD card / by usb generated by for example Cura you don't see this offset?

[peteruithoven]

@companje Would be good to check the Z position of the first lines of the G-Code Doodle3D generates (after the start g-code).

[dr-error]

@peteruithoven Yes, the offset is there as well in other prints.

[peteruithoven]

Maybe I mis understand but shouldn't you re-level your bed then?

[dr-error]

That might do the trick. I'll try that but calibrating the bed of this printer is a real pain. To get it straight is very hard. When the height must be fixed the calibration becomes almost impossible. It would be easier if I can set an offset value somewhere.

[peteruithoven]

Also relevant: Doodle3D/doodle3d-client#238.

We could try figuring out here with out Ultimaker Original how the start gcode could be tweaked to set an offset.
We could also make this a separate setting and incorporate this in the g-code generation. I'm afraid we can't easily add another start gcode variable (like printingTemp) because after changing the printer type users have a custom start gcode config, which makes that the default (in conf_default) isn't used anymore.