PETG supports with PLA

Bambu Lab H2 Series Bambu Lab H2C
1

I’m having trouble with pieces coming off of the supports. I’m using PLA as an interface for a PETG model. It’s working too well. I believe part of the problem is a lack of surface area as the supported parts are kind of spherical.

I’m running three interface layers with 0 spacing at 60/150 mm/s. Aligned Rectilinear infill, so it’s not crossing. I have:

  • maxed out the temp for PLA
  • unchecked reduce infill retraction
  • painted a larger support area
  • have tried different interface patterns
  • have tried tree and normal

Anything I am missing?

2

Is the Z offset also 0mm?

did you test it on a flat surface to see if they bond enough?

Also drying helps a lot.

3

Yes,. Z is set to 0, and both filaments are bone dry. I haven’t tested on a flat surface.

4

I would first try testing it to see if they properly bond.

If not, then you need to find different PETG to support it. Or another support material.

So far I haven’t had serious problems with PETG-HF supporting PLA Basic and PLA Matte, and vice versa.

5

I would try adjusting both the PLA temperature and the print speed. A too high PLA temperature can make it soft enough for the PETG to deform it.
I have used this combination without any issues, but I kept my usual PLA temperature and speed settings.