Wrong settings on default profile

[alnavasa 5]

After 4 unsuccessful prints I noticed something was not right

 

For whatever reason,

for print core AA 0.25 for ABS Regular Fan Speed is set to 40% 

for print core AA 0.4 for ABS Regular Fan Speed is set to 2% 

I have the feeling that other settings might be wrong too. 

I thing this is a big issue that needs to are addressed soon in 5.6.1 version.

 

 

This is on a fresh install after I have just reformatted the complete OS of the computer

Cura 5.6.0

Mac OS 13.6.3 (22G436)

Ultimaker S5

 

 

 

Edited January 4 by alnavasa

[FredericM 1]

Hi,

 

Could you tell us more about the actual issue you're having with printing?

Those fan speeds you are seeing are correct. With ABS, we use a very low fan speed to increase the layer adhesion. As a side effect, the visual quality is a little bit less, a necessary tradeoff. For the AA 0.25 print core, we focused more on visual quality over mechanical properties, so we increased the fan speed for that profile.

 

Regards,

Frederic

[alnavasa 5]

Okey, 

¿For print core 0.4 we use 2% fan speed and for print 0.25 core we use 40%? that's a huge difference, you sure this is right?

Its like going from no fan at all to almost half speed of fan (that we all know is almost like 80% in real life, not much difference on Ultimaker machines between 50% fan and 100% fan)

 

I am getting not good adhesion on first layer, I have printed a lot of ABS at 0.4 core with zero issues using just hairspray, I am talking about 20+ models with this same printer on default settings, and now, printing the same model with the 0.25 failed 3 times in a row. Using same hairspray using same spool of material, same room, same machine.

[PaulKuiper 11]

Hi,

I checked the history of this setting.

The 40% fan speed for the AA0.25 nozzle at 0.1mm layer height has been in there since at least 4.13.1 (I did not check versions before that). However,  versions up to 5.1 have an initial layer fan speed of 0%. From 5.2 onwards this changes to be equal to the regular fan speed (=40%). In 5.2 we changed the initial fan speeds to be equal to the regular fan speed because we noticed a large build up of extrusion force with low fan speeds in the first layer leading to an elephant foot and a harder to remove brim. So we set the initial fan speed equal to the regular fan speed. Testing a variety of materials and print modes showed that this did not significantly affect the first layer adhesion and applied it to all profiles. However, we did not test AA0.25 ABS 0.1mm, it is a bit of a corner case. Thanks for reporting this, we will investigate it.

Edited January 8 by PaulKuiper

[alnavasa 5]

Thanks for the info, now I get it, 0.25 just for visual prints, not engineering,

I was looking for the finest functional prototype I could get with the 0.25, not sure now, but I think I also tried with 0.06 layer height. 

 

 

In the past with PLA I tried 0.06 with the aa0.25 and it delaminated easily, thought it was a bad spool (very old one) I now get that that print core nd that profile are not meant to have strength with this print core just visual quality.

 

 

Thanks for all the info!

[PaulKuiper 11]

Hi Alnavasa,

We only have a 0.06mm layer height print profile for the AA0.4 core. The back pressure is too high for a AA0.25 core when printing at a 0.06mm layer height, so we do not recommend that.

We will re-check if the 40% fan speed is really necessary for ABS to keep good visual detail. If not we will lower it to get better part strength. 

[alnavasa 5]

Great news! Thanks!

[PaulKuiper 11]

Left is 2% , right 40% fan speed. The quality in overhangs is clearly better for 40% fan speeds. Overhangs up to 70% are printed OK with 40% fan speed and overhangs up to 50% are printed OK with 2% fan speed. Also checking 5% and 10% fan speed to find a balance, but whatever the result for the regular fan speed we will reduce the fan speed in the first layer back to 0% for this print mode in Cura 5.7.

[PaulKuiper 11]

Regular fan speed 5%.

OK, so a fan speed of 5% has the same quality as a fan speed of 40% (can handle 70% overhang). So we will change the regular fan speed to 5% and the initial layer fan speed to 0% (for adhesion robustness).
Thanks for reporting!

[alnavasa 5]

Nice work there!