Protopasta HTPLA problems

I’ve been having trouble in a dual-extrusion print using Ninjaflex and Protopasta’s High Temperature PLA.

I’m satisfied with the ninjaflex extrusions. I am having a lot of trouble getting good prints with the HTPLA.

I haven’t had any trouble with single material prints using HTPLA. It seems my problem arises from frequent retraction of the protopasta filament. The filament is visably chewed-up inside the extruder head from the gnarled bolt pulling and pushing frequently. I’ve adjusted the various retraction settings to no avail. The only thing that seemed to work was increasing the layer thickness to .5 which makes for a solid print but with weak adhesion of the ninjaflex material.

In the pic attached, the object on the right was printed “successfully,” and the left is my current problem. The early layers extrude unevenly.

I’ve adjusted and shortened the bowden tube to reduce the stress on the extruder but I’m still having problems.

Nozzles are new. Temps are HTPLA: 220, Ninjaflex: 215