Printing with PETG - support material

Folks - I am trying to print with PETG on MakerGear M3. The issue I encounter at this point is the following:

- I have dual head printer and use PLA as my support material as this allows me to easily purge the support after piece is printed in PETG.
- The problem is that I had bad layer adhesion at the point where PLA support touches PETG. In other words, it looks like PETG does not stick to PLA and I get bad surfaces at those joint layers.
- I tried turning fan off at that transition layer but it lead to bad stringing. I also print at 150 mm/s which I like and not sure if increasing the speed further would help



Much appreciate any suggestions and alternative solutions to be able to print with PETG when I have to use support for overhangs

I only have the M2 so I just use very low infill when I have to use support when printing with Petg as it is not suited for support as you know. I set my XY speed in S2D to 200 rather than the default 300mmS for non printing motion. This is where a lot of stringing happens. I also never print much faster than 50mmS if the part is not a large simple shape. Slower = less strings.

If using S3d, you may want to set your support to print 1 layer of 100% dense support this will give the PETG a smooth surface to land on and make sure your upper vertical separation is not set more than one.
Good luck!!

I never use a fan when printing with PETG

Recently I have starting using Makergear brand ABS in place or PETG if the part will not be outside or exposed to sunlight.

and you're printing too fast :-)

Quote:

---

Originally Posted by airscapes

I only have the M2 so I just use very low infill when I have to use support when printing with Petg as it is not suited for support as you know. I set my XY speed in S2D to 200 rather than the default 300mmS for non printing motion. This is where a lot of stringing happens. I also never print much faster than 50mmS if the part is not a large simple shape. Slower = less strings.

If using S3d, you may want to set your support to print 1 layer of 100% dense support this will give the PETG a smooth surface to land on and make sure your upper vertical separation is not set more than one.
Good luck!!

I never use a fan when printing with PETG

Recently I have starting using Makergear brand ABS in place or PETG if the part will not be outside or exposed to sunlight.

---

Airscapes - much appreciate your feedback. I've dropped the speed to 50mm/s and reduced the fans to 25% which lead to much better results. I've set dense support layer to 4 with 100% infill which made huge difference. Thanks again for your advice.

one thing to bear in mind is that printer manufacturers still quote 'top speeds' that are just not practical for printing.
Plus different metarials need different print speeds.
Pet-g doesn't like to be printed much beyond 50mm/s.
Pla will print as fast as your machine can manage.