Cetus MK2 Hemera / Hermes Extruder Mount

Last crawled date: 4 years, 2 months ago

I love my Cetus MK2 with the TinyFab.xyz CPU-WiFi upgrade. I really wanted to be able to print flexible filament with it but the stock extruder/filament pusher can't do it reliably. I ordered a Hemera and mounted it. It works GREAT! I haven't printed any large items yet but many small TPU tests such as GoPro miniquadcopter mounts. I was surprised that a PLA mount would be rigid enough. I considered using an aluminum plate but thought I would try a PLA printed mount first. It seems to be stiff enough.
I ordered the 24V Hemera kit and a 40x40x10 Noctua 5V fan. The thermister and 24v heater cartridge that came in the Hemera kit are not compatible with the Cetus MK2. And so I reused the original 18v cartridge and pt100 temp sensor. The fan that came in the kit operates on 24 volts but the printer supplies 5 volts to the fan so I installed a new 5v Noctua fan. I don't know the connector type for the fan so I cut one off of a spare Cetus Extruder to plug into the Extruder Distribution PCB. I added a 4 pin jst-xh connector to the Hemera stepper motor harness to match the Cetus stepper motor receptacle on the Extruder Distribution PCB. For part cooling, I used a 5v 50mm brushless fan and made a custom mount to the Hemera motor nuts. On the fan power wire, I crimped on a 3 pin jst-xh connector, filed down the outside plastic a bit and forced it into the unused fan connector on the Extruder Distribution PCB. Update-I found that the correct connector type is a JST-EH.
The X,Y and Z home positions were slightly offset from the original. I modified the position values in the Smoothieware Printer Configuration (alpha_max, beta_max, gamma_max). I also changed the extruder.hotend.steps_per_mm to 818 for the Hemera extruder gear ratio.
Parts:
TinyFab UP!/Cetus CPU V5 (WIFI)
E3D Hemera Direct Kit (1.75mm)
Noctua NF-A4x10 5V, Premium Quiet Fan, 3-Pin, 5V Version (40x10mm, Brown)
Comidox 5Pcs Black Brushless DC Cooling Blower Fan 5015S 5V 0.1-0.3A 50x15mm
Partstock 230pcs XH 2.54mm 2/3/4/5 Pin JST Connector Male/Female Wire Cable Header Housing Adaptor Terminal Kit
Misc M3 screw assortment(6mm-12mm)
M3 washers
JPONLINE 50set, 2.5 EH CONNECTOR 3-Pin JST plug (Male, Female, Crimps)