How badly does moisture effect PLA?

[insta]

I found a baggie of some demo filament labeled PLA+. I think it may have come with my esun PETG preorder. Maybe some "enhanced PLA" is what you're looking for? You could also just keep upping the temperature until it stops delaminating. You can also try larger layer heights, which have better Z strength (fewer layer to layer bonds). With a .35mm nozzle, you can probably get up to .3mm layer heights.

That stuff came from MG actually ... I have some too, and haven't used it, because I'm waiting for that special time I would try it for this, but mine is black and the parts must be yellow.

Jules: I'll try again with 1 perimeter and more infill. 1.2 extrusion multiplier gave a rough surface finish. The parts are already oriented such that the infill isn't long runs.

[Bratag]

Why exactly do they want PLA. If these are structural parts under some stress why wouldn't ABS or PET be the better choice? Or do they require the rigidity of PLA ?

[Jules]

What filament exactly are you printing with? (Brand and color.) Some of them do have some weird characteristics that you have to work around....is it eSun? (Got a picture of one of the delaminated ones showing how it broke up?)

Edited to add another thought:

If it's delaminating between the layers (like at the perimeter) it might also help to decrease the distance between the nozzle and the bed for that first layer by adding a negative number in the Z-Offset of the G-code area. (Assuming you are using S3D.) I have two glass plates that I switch between, and one of them is just a bit thinner than the other. When I use that one, sometimes the first layer doesn't get good adhesion, and that can weaken the rest of the perimeter. So I add -0.3 mm to the Z-offset so that the first layer gets a little squished, instead of laying down in a rod shape. That helps a lot. (I have my Z-stop calibrated for 0.6 mm gap. Adjust that number if yours is different....don't want to smack the nozzle with the bed.)

[insta]

Why exactly do they want PLA. If these are structural parts under some stress why wouldn't ABS or PET be the better choice? Or do they require the rigidity of PLA ?

The first batch was ABS, they were too weak, and of the options I presented PLA was the next choice. A lot of the factors involve what is and isn't available in what colors -- translucent yellow PET wasn't good enough.

[insta]

What filament exactly are you printing with? (Brand and color.) Some of them do have some weird characteristics that you have to work around....is it eSun? (Got a picture of one of the delaminated ones showing how it broke up?)

Edited to add another thought:

If it's delaminating between the layers (like at the perimeter) it might also help to decrease the distance between the nozzle and the bed for that first layer by adding a negative number in the Z-Offset of the G-code area. (Assuming you are using S3D.) I have two glass plates that I switch between, and one of them is just a bit thinner than the other. When I use that one, sometimes the first layer doesn't get good adhesion, and that can weaken the rest of the perimeter. So I add -0.3 mm to the Z-offset so that the first layer gets a little squished, instead of laying down in a rod shape. That helps a lot. (I have my Z-stop calibrated for 0.6 mm gap. Adjust that number if yours is different....don't want to smack the nozzle with the bed.)

It is eSUN yellow PLA (inland brand, microcenter), and that has good results when I up the extrusion multiplier to 1.09. I'll be sending a batch of them tonight to get their feedback.

[Jules]

Good! Hope this batch works out okay.