2nd Nozzle Ripping up build from 1st Nozzle

[Explorer71]

I have this problem with my Dual Nozzle M2. As I am laying down the first layer, the other nozzle catches on any projection and rips it up, ruining the piece. I've check to make sure both nozzles are at the same height cold. This would appear to be an unavoidable problem which will only get worse with my new RoVa3D printer with 5 nozzles. Has anyone else had this problem? I am using the GeckoTek build plate which works great. Is there anything I can do/set to minimize this problem? This would also be a problem with delicate supports getting caught and broken off.

Thanks

[Tim]

Has anyone else had this problem?

Yes; I designed an entirely new dual extruder method just to deal with it.

I assume you have this problem only when making dual prints, because it's easy enough to leave the unused extruder pushed up a few millimeters to stay out of the way.

Generally speaking, you should not have this problem if everything is on level, but it really depends on the print and on the filament. My biggest problem is with PETg (I don't use ABS but it would have the same problem), since it likes to warp with shrinkage, which can be undetectable with some prints and a real pain for others. Also on overhangs or anything that gets thin enough, the plastic wants to curl in the heat from the nozzle, which also causes the plastic to stick up a bit from the print where it can collide with the other head. Good path planning would be the best way to deal with it, but I haven't seen any slicer software that has any intelligence about where the inactive head is during a dual extrusion print.

I don't have much advice about dealing with the problem other than avoiding the kinds of print geometries that cause bad warping (long, tall, thin vertical walls, for example) or have severe overhangs. Watch carefully where things are placed---features on a print that are the same 30mm or so apart that the extruder heads are distant from each other can possibly be avoided by rotating the object.

[Jules]

There's a way around it. Read through the discussion at the link on how to set your gap under various temperatures for the original M2 duals: (Not the Rev. Es)

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