Well, unfortunatly it won't finish the model... I've given up.

After repalcing all the obvious parts without the wanted outcome I think to understand where the problem lies.
During the printing of all those tiny struts the nozzle travels a lot but only has to give out a tiny bit of fillament.
When it goes to travel it retracs the fillamen 5mm t to avoid stringing. But because it needs so little fillament to print those struts it keeps retracting and extracting on the same 5mm of fillament, wich wears out that piece of fillament in the extruder, and the gear loses grip.
I have seen this happening on a removed piece of fillament, it had deep worn out sections over a short length, intermittent as paintlines on the road.
Shortening the retraction length helps avoid this, but then the model suffers from exessive stringing and doesn't look nice. And the stringing is also very deep into the models core structure wher it is vissible but practicly un-removable.
So as said I've given up trying to print this model.


Martijn.