Overextrusion with TPU95

[4instudent 1]

Hi everybody

I´m extruding with red TPU95 and PVA testing the compatibility. The problem is as soon TPU95 stop extruding for building, and the PVA start printing, the TPU95 keeps melting a short flow of material instead of stopping. As a result, There exist an undesireable overlap between of both materials.

I've tryed changing the "retraction extra prime amount" to 0 but It doesn't work. 

If anyone can help me I would be so pleased.

Thank for your attention

[Brulti 177]

TPU and PVA are listed as experimental by Ultimaker, thus you may encounter other problems.

 

One solution to your problem would be a prime tower, whihc would gives TPU time to cool down and stop extruding before PVA starts printing the support of your model.

[gr5 2,224]

I was thinking prime tower also.  If the nozzle leaks a bit hopefully not enough to fall into the print before you wipe that leakage off on the prime tower.

 

Also you might want to print the tpu slower than normal such that the pressure in the nozzle is lower (hence hopefully less leaking) and you might want to increase your retraction a lot.  Watch the tpu in the bowden.  You want it to rest on the bottom of the bowden arch when retracted.  You might need to go as high as 10mm or even higher for retraction distance if the tpu is bunching up a bit.

[4instudent 1]

Thanks for the solutions, I will try IT and I will show you how It has worked.