Dual Extruder 1.75mm Water Soluble Support

Hey all,
I have been attempting to print 1.75mm abs with 1.75 water soluble support on the Taz 5 dual extruder. I have been successful with printing 1.75mm abs on a single extruder with great quality prints but this combination has me stuck. I have tried to research it and it seems like I might be in new territory here so i’m looking to the experts to help. I first attempted on Cura with 3mm abs and 1.75mm support in a combined print (Nintendo keychain) and it was ok but I couldn’t specify the second filament size as being different so it didn’t fill as well. Also on Cura I couldn’t specify the second filament size to be 1.75 for support material so I moved onto slic3r. In slicer it either printed both like 3mm or both like 1.75mm so i finally stuck 1.75mm abs in the first. Now the prints start out great but as soon as it gets to 1.5mm above the bed it just goes nuts and over extrudes, makes the overall shape deformed and I cant tell what is happening. I have changed print temps, retraction lengths, extrusion multiplier, layer heights, infill density, etc… I am out of ideas and the print really leaves me with no good explanation for whats going on. Any input i’d love to hear and hopefully I can use up this water soluble support. Thanks

My initial thought is that you are going to have issues with the fact that water soluble filament (PVA) has a much lower melting point that ABS. For ABS I would use HIPS as the dis-solvable support. PVA’s melting tem perature is much more compatible with PLA.

What version of Cura are you using? Version 14.09 supports different filament sizes and the latest Cura is version 18.03

Yeah i’m running it at 235 as the recommended temperature for the PVA. We’ve tried HIPS and ABS but we didn’t like how slow the dissolving was and how it also affected the ABS in the D_Limonene. And I was using the latest version of Cura I couldn’t find where to change the second extruder filament size but i just recently found it. I’m going to run a print with cura and see how it does with this task.