I was looking into a way to occasionally print Ninjaflex or other real flexible materials (85A)
There's no way you'll be doing that reliable with a bowden setup (ok, I've seen people using oil in the bowden but nahhh), so I compared a quick and dirty direct drive conversion on an Ultimaker2 head (tested on my DIY GO) and on the ultimaker S5
**** first a warning, Ultimaker does NOT want you to open the S5, it contains an open style high voltage power supply, so it's DANGEROUS!!!, also the electronics can be damaged and I'm pretty sure you loose your warranty.
I used two materials for testing, Extrudr TPU Soft and Ninjaflex, both 85A.
I used the regular feeder from the UM2+ , combined with a pancake stepper motor (LDO-42STH25-1404MAC#190920) this stepper is less than half the weight of the normal stepper. I had to cut some length of the shaft to make it fit. The stepper has a different # steps per rotation and as it's impossible to change the steps setting for the S5 on one feeder it needs compensation in flow (200% flow = 100%)
Obviously the result is a crazy top heavy setup, but if you just want to print an occasional gasket it should be fine, specially since you need to print materials this flexible very slow (15 mm/s) anyhow. On an Ultimaker2 the extra weight is enormous, on the S5 not so much as it's very heavy already anyhow.
The nice thing is you can see into the feeder so during testing it's easy to spot when the feeder can't cope if you try to speed it up to much. If something goes wrong it's mainly during the first few layers, so watch them... otherwise you'll spend a few minutes again taking the feeder apart...
To validate the basic setup I printed regular PLA on both converted machines, to make sure the setup (including changed steps/flow due to different motor) was correct.
On the UM2 head the ninjaflex was pretty easy to get working, i managed to print with constant and reliable extrusion using a 0.4 nozzle.
The materials prints best around (I tested with 0.15 layers)
Flow : 110-115 % (with feeder tension set to lowest point)
Temperature : 210 c
Speed : 15 to 20 mm/s
The easiest way to test temperature and flow is by printing simple cilinders, foir the S5 you can use the "tune" menu to play with values on the fly.
Getting ninjaflex to work on the S5 proved to be more difficult than on the UM2, at the same settings using an 0.4 mm nozzle prints failed all the time, it seems the CORE, is much more of a challenge that a UM2 setup. I blame the longer filament path, and the metal tube of the core. Only when I changed to the 0.8 nozzle and the CC0.6 I was able to get reliable results.
My main S5 tests are with the CC0.6, atm my best results are with the following settings;
The S5 levels pretty close to the bed, making every print fail at normal flow rates.
Layer height 0,15
Initial layer height 0,25
Top/bottom pattern & Innitial layer pattern ; concentric (avoid lot's of small lines, head vibration)
Innitial printing temperature/ innitial layer : 230c
Printing teperature : 215c
Skirt/Brim flow 140% (= realy 70%, due to the different stepper motor)
Innitial layer flow 150% (= realy 75%, due to the different stepper motor)
Flow 225% (= 2x the real flow, due to the different stepper motor)
Print speed 15 mm/s
Innitial layer speed, Skirt/Brim speed 10mm/s
Cooling at 100%, start with 20% and let it rise over 10 layers)
Turn off the flow sensor (in the settings menu) on the S5, as you're not using that feeder..
Conclusion, even if you eliminate the bowden, printing 85A flex on an Ultimaker S5 is still a bit of a challenge. The used feeder (UM2+UM3 model) and filament path are not ideal. But, usually if you make it past the first few layers, and have relatively simple prints that keep the flow going it's very well possible to print ninjaflex on the S5.
I have not experimented a lot with it jet, but I also managed a simple test print using PLA for support on the 2th extruder.
the hardware hack;
The feeder plate mounts to 3 screws of the head, so you can leave one and the head will stay assembled during mounting.
I made a little breakout plug for the left stepper motor on the back of the printer, so I can change between direct and bowden in just a few minutes. I just leave the black mounting plate on the head. In needed to make a hole in the bottom plate for the DIY extension cable. I isolated the plug with hot glue.
some side notes;
Cura can sometimes create fantastic vibrator g-codes, not nice with this heavy setup, so one thing you can do to prevent this is to change line fill to cylindrical fill, and check the layer preview.
ninjaflex openRC wheel, printed on S5
extrudr TPU soft (85A just like ninjaflex) gasket, printed on S5