I have been trying to practice printing this, http://www.thingiverse.com/thing:533814/#files, so I can get better at printing with this dual head. I have the printer pretty well aligned, my issue is with the extrusion of the NinjaFlex.
I am running PLA into T0 and NinjaFlex int T1. I have worked the extrusion rate, retraction rate and start up rate out with PLA, but I seem to be all over the place with the NinjaFlex. I have had an extrusion multiplier from 1 to 2, retraction rate of up to 3mm, start up (after retraction) of up to 1 mm… What happens every time, I not only ooze and print the squares with the oozing NinjaFlex while the PLA is printing, but when it starts back up, nothing comes out until a good 10 to 15 seconds… By that time it is almost time to change heads, and when it does come out, it starts slowly. Then it gets better when infilling. I have loosened the bolt on the extruder, varied the multiplier, retraction, extra restart distance…Please hep me figure this out… What could I be missing?
There are a couple of things you are going to want to tweak to get some better prints with the Dual.
Depending on the slicing program, you will have two retraction settings. The first will be for the standard retraction moves, and the second will be for when the print head is disabled. You are going to need a large retraction amount (20-25mm) when the second toolhead is not in use. This should cut down on the dripping when the PLA is printing.
I highly recommend using a priming tower and ooze shield to help clean up the print as well. (Cura) The priming tower will get each toolhead flowing after switching to the other filament, and the ooze shield will wipe each toolhead when moving over the print.
It DOES help. Only one thing sounded odd, but I think I understand why. When watching the NinjaFlex training videos, it was cautioned against using too much of a retraction as the flexibility factor comes into play.
To the other points, the bottom line is this, I thought throwing money at the printer would make it better…WRONG. I purchased Simplify 3D. While it is a great program, do not get me wrong, it is funny that I find myself using Cura a little bit. Now, more… and it was free…