Extrusion problems Ultimaker 3 Extended

[YoloDoge1 0]

For my work I am working on a 3D printing project in which impact protectors have to be printed with TPU 85A on our Ultimaker 3 Extended. For this I made a print profile in Cura, where I made a copy of the standard TPU 95A profile and then adjusted the settings that are recommended on the website of the manufacturer of the filament that I use. At first glance, everything seems to be normal:

 

 

Now every time, when printing the first layer, the lines in the third part are extruded thinner and thinner and eventually no more filament comes out of the extruder during printing, see the result below:

 

 

I've already been playing with the bed-distance of the first print layer, but that doesn't help. I also had the idea that the pressure of the feeder was set too high, so I have also reduced that a bit, but that is to no avail. I also noticed that the roll of filament turned a bit stiff on the shaft, so I put some lubrication in between so that the feeder doesn't have to pull too hard on the roll (I thought that could also cause problems). That also made no difference.

 

Do any of you know what could be causing this problem and what I can do about it? I have had exactly this problem before with PLA, where I have also not gotten the problem solved. Another factor was that the filament was stuck in the extruder. The cause of this is probably too high a temperature of the hot-end, but I have not yet found the ideal temperature and had time to test it.

 

I have also attached the current 3mf-file.

 

I look forward to your reactions!

UM3E_3 sets kartelrandbeschermers.3mf

[gr5 1,930]

There are many possible causes but one that strikes me immediately is that the 3rd fan my not be rotating.  In the print head there are 2 side fans but there is also a fan in the "door" of the print head.  Make sure that's spinning when either core is above 60C.

[gr5 1,930]

Did you check the fan?  If it's working I can give you a list of other possibilities.