Bad Layer Bonding

[3DPL 0]

Hello!

Can please someone help me?
I'm having bad layer adhesions with Colorfabb's Shining Silver PLA on a 0,4mm nozzle and Colorfabb's Intense Green PLA on a 0,25mm nozzle. Normally everything goes perfectly fine. But with this model I'm having some real troubles. The green text isn't even sticking to the grey entirely.
I'm printing with an Ultimaker 3 Extended, printing temperature is 205˚C, build plate temperature is 60˚C. Printspeed for the grey is 100 mm/s and for the green 50 mm/s. Layerheight is 0,2mm. What can I change to make it look better?

Kind regards

[DidierKlein 729]

Hi and welcome to the community!

 

I think the print speed for the grey is to high, causing that underextrusion

 

For the green text, i think the angle is to steep and causes the print to fail, it's maybe also a problem in the model itself

[peggyb 169]

the speed woud be too high for the green as well, considering you are pushing it through a 0.25 nozzle. The material needs time to heat up for extrusion. Maybe make a smaller test piece first, like a little cube with text to test the best speed/temp settings.

[3DPL 0]

Okay, thankyou for the tips. I've adjusted the model slightly. The text is now in an angle of 45 degrees. And I've adjusted the print speeds. Hopefully the results will be better now. How about the fanspeed can this influence the print layer adhesion?

[gr5 2,167]

Layer adhesion is basically never going to be an issue with PLA.  Using the max fan that 99% of the printers out there are capable of will not be enough to cause layer adhesion issues.

 

However with higher softening-temp materials you definitely need to reduce the fan.  Such as ABS, Nylon.  Pretty much anything but PLA needs less fan.  Typically 3% to 5% is good on non pla materials on the UM3 depending on the material (these are fan speeds for the UM3 which doesn't start slowing down until around 8% and for normal printers you want 30% to 50% fan speed typically for non-pla).