Second extruder pulling up first layer

[ch0g]

Hi all,

So I'm having a hard time with my DaVinci Duo...

When printing the first layer with my right extruder the left extruder is simply pulling up the print when it passes over the freshly laid plastic. I have spoken with support but the retraction vertical lift didn't seem to make any difference.

Is there some gcode or other setting I can use to hold the left extruder retracted/out of the way from the print bed?

Thanks

Brett

[BaudR8]

This means your extruders aren't level and that your left extruder is at a lower point than your right extruder, causing it to drag. I personally owuld recommend fixing this hardware issue by diassembling the carriage and extruder assembly and raising the left hot end up a smidgen, although not everyone is comfortable doing os.

[Fred B]

Once things are leveled properly try printing with the second extruder turned on at a lower temperature.

If the first layer is excessively over extruded a properly leveled machine can still drag some. If the second extruder is cold it may hit and knock the print off. If the tip is hot it has a better chance of sliding over the layer. I run the second extruder at 200C when I'm printing ABS.

If you want to turn off the second extruder after the first layer just add a new process at layer two with the extruder off.

[JoeJ]

Adding vertical lift is a good idea. That will make sure that the extruders are both positioned at an elevated height whenever they do rapid movements. However, it will still need to be at the normal printing height when you are actually extruding. So if your nozzles are misaligned, or there is dried plastic on one of them that causes it to hang down below the minimum point on the other nozzle, you're going to have problems.

So z-lift will definitely help reduce this problem for travel movements, but you may still need to properly level your nozzles if you are seeing the issue during normal printing as well.

[Rebekah_harper]

when levelling the bed, everything should be heated up to working temp. here you should see the difference in height.

[ch0g]

Thanks a lot guys. Keeping the secondary extruder hot (190c) has fixed the problem. It just melts a little of the first layer as it passes through it.

Retraction lift doesn't seen to work, the extruder appears to stay level right through the print so not sure on this?

Is Z-lift referring to retraction lift or is that somehow different?

And lastly, leaving the secondary extruder at 190c without extruding for several hours will that cause a jam/cook the filament?

Cheers

[JoeJ]

Retraction vertical lift is only added when you actually do a retraction. So if you want to lift on every move, you would need to also retract on every move (lifting doesn't work well if you don't retract first).

If you click on the Advanced tab, there are several options for retraction behavior on the right side. If you want to retract on every move, you would need to make sure that "only retract when crossing open spaces" is disabled and that "minimum travel for retraction" is also disabled.