Tried printing the support interface layer with petg using the second nozzle like I’ve seen online but at the first extrusion after a z hop movement across the model it doesn’t stick and leaves a blob. I’ve tried what I think are some pretty hectic retraction settings with no improvement. Besides that the idea works great. After the initial mess up itll lay the petg down fine and boy oh boy is it nice to remove.
Cheers.
I had that same problem when I got my H2C. Bumping the PETG nozzle temp (IIRC to 255 or even 260°C) resolved it at the time.
Not a good idea with the 0.2mm nozzles though: heat creep!
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Same experience, very mixed bag results with PETG on aux extruder for support. And for prints.
But as matter of fact Bambu do not recommend PETG on this extruder.
Also I do had better results with higher temps, but still not stable enough. Sometimes stick, sometimes does not and create blobs.
And it does matter what kind of PETG brand and specs you are using. Polymaker basic PETG is complete disaster on the aux. And it is so so on the main.
Lately got the supper expensive Bambu support for PLA/PETG filament. And it seems to work better, but did not tried too much so far.
I’ve found if you increase the number of interfaces from 2 to like 4, it can recover from a sloppy “first petg on the pla” so long as it didn’t like drag the whole model down with it. My aux nozzle petg PA is 0.3■■. ludicrous high, hard to expect perfect placement
Looks like most of the problem is that its not extruding right away. It’ll go maybe 5 seconds before any petg starts coming out and then itll not adhere and then leaves a blob.
I am always using prime tower and set almost every possible setting + dialed the speed in some trials down to 10-20mm. One time tried without prime tower and it was not able to finish the print.
But with prime tower It start promising then in the middle of print does not stick and next layer become mess. So it was really hit or miss for me so far. I will try most probably with other brands and models PETG, and there is one specific type that is shown as compatible with AUX in the Bambu list. I think it was translucent, so maybe I will try with it.
But anyway it seems like big time killer as the prime tower bring the times up 10-30%, depending on the model. So I become more and more hesitant to use different material for support, for my current needs. And will try to improve on multi plate printing.
I would not be so hesitant to buy more from the expensive support material, as in addition it is support for bot PLA and PETG. So one roll for both materials, which is grate! But with primer tower it waste too much time and too much material + place. So this technology for me is not “there” yet. Of course it is usable and someone could find it helpful, but I do not like it for my usage. They need to figure out better way for priming and not waste time and material like this.