LPFRG itself doesn't sell soft filament for rpinting rubberlike products, for this kind of filament like "Ninjaflex" modifications to the filament feeder could be neccessary (http://www.thingiverse.com/thing:321258).
Because the HS is "pushing" the filament on quite a distance thru the tubes from the feeder/extruder towards the extruder heads I think this might be a problem with softer filament?
Has anyone experienced printing soft parts, eventually without modding the creatr HS?
some info regarding filaments here: http://www.ifeelbeta.de/
yes i am trying to find a good setting for the ninjaflex (normal) and ninjaflex semi. I manage to print some parts, they are not especially neat but it sort of works. you need to run VERY slow! 500-1000mm/min. also I made a small insert in the feeder, just a small tube of 18mm long, 3mm outside, 2mm inside (brass or alu) you unscrew the top fitting that holds the teflon tube and drop in the tube, then screw on the fitting again. and you need a 0.5mm nozzle. I have it set at 0.2mm layers. but I guess with some tweaking and trying you can get better results.
the worst problem is that the filament pushes out of the extruder gear when there is too much pressure. if this was resolved I think it could work OK. I will try to make a new fitting connector with guides down to the gears all closed so the filament cant get out.
You can find such an anti-twisting part that I made here: https://github.com/chili-epfl/3d-print-objects/blob/master/stock/leapfrog-creatrhs-aftermarket-mods/leapfrog-creatrhs-extruder-filament-guide-after-motor/stl/leapfrog-creatrhs-extruder-filament-guide-after-motor.STL
Here are some settings that I cooked up for various filaments (including Ninjaflex and other flexible filaments): https://github.com/chili-epfl/3d-print-config/tree/master/leapfrog-creatrhs Use these at your own risk.