Rostock does not go to build plate before starting the build

[Hansen]

Hi all,

I finished my Rostock build a few days ago, and for some reason the printer no longer goes to the build plate before starting the print, so it basically air prints .

To get around it, I've added the custom GCode before the prints start:

G0 Z0 F3500

which lowers the hot end to the center of the platform. However, this is not good, because the nozzle leaves some oozing filament right in the center where the print is being build.

Any idea how to make the printer go to the platform the right way? Maybe a better GCode, which goes directly to where the print starts in the XY direction?

Thanks
Hansen

[FDM_Process]

Sounds like you might need to re-calibrate your z fields.

I'm not completely sure I understand your problem though.. when I hit print the arms go to the top and stay there until the hotend and bed are up to temperature... which is what your printing should be doing.
You don't want your hot end to be heating up on the build plate.

[Hansen]

Sorry for my poor explanation. It does go to the top to heat up, but when temperature is reached it doesn't go to the platform before it starts printing... It's like a line of Gcode from Slic3r is missing, and I can't figure out, what I turned off

[FDM_Process]

Thanks for clearing that up.

Did you set the maximum and minimum heights on the controller? I would run through the steps involving setting the Z-Height on page 217 again. I had to run through this part twice during my build.

[Hansen]

Actually, I have calibrated the Z height several times, because I've been fiddling around with determining how close I should be to the platform...

Anyway... I decided to try to remove my custom GCode to lower the hot end to the platform, and... now it works - i.e. without my custom command (??). I have no idea what has happened, but right now I can concentrate on the other issues that I'm trying to figure out (stringing, max. print speed without sacrificing quality etc.)

Thanks for your input!

[singh336]

Sorry to bump, but I have the same problem , it only happened to once.. any reason for this ? After it printed in the air for a bit it came down to smash into the glass bed. It was really bad.

[Brian]

Every so often this happens to me. Something is getting screwed up in the firmware. Power cycling the machine seems to fix it. It could also be the repetier host software and resetting the machine causes the host to reset and start working. Next time it happens to me I plan on closing repetier and restarting it to see which one is at fault.

[singh336]

good to know, glad it wasn't just me and it is a known issue.