Table of Contents
Revo Hemera XS Summary
- Drive Type: dual drive with adjustable tension idler
- Max Printing Temperature: 300°C
- Nominal steps per mm (x16): 397
- Recommended current: 1.4A Peak (~0.99 RMS)
- Filament diameter: 1.75mm
Service Temperatures
Note, these are maximum ambient service temperatures of the components used and not a guaranteed operating temperature of the system
- Fan: 50°C
- Motor: 85°C
- Polymer bushing: 90°C
- Bearings: 100°C
- Acetal idler components: 120°C
Fan Specification (Direct)
- Width: 40mm
- Depth: 10mm
- Cable: 1000mm
- Bearings: 100°C
- Voltage: 12VDC and 24VDC
- Current: 0.08A (12V) and 0.04A (24V)
- RPMS: 7500±10% (12V) and 6900±10% (24V)
- Speed: 7000RPM
- Connector: Dupont 0.1"
- Startup voltage: 6 VDC (12V) and 12VDC (24V)Airflow: 6.8 CFM
- Static Pressure: 4.55 mmH20
- Noise level: 33.6 dBA
- Weight: 14g
Motor Specifications & Diagrams
- Motor mass: 160 g
- Motor wire length: 1000mm
- Phase number: 2 phases
- Rated voltage: 3.22 VDC
- Recommended Current: 1.40A Peak (~0.99A RMS)
- Resistance: 2.3Ω per phase
- Holding torque: 180mNm
- Detent torque: 10 mNm
- Rotate direction: ABĀB̅ CW
- Step angle: 1.8°
- Rotor inertia: 7 gcm²
- Rotor inertia: 24.3gcm²
Maintenance
- Do not remove the grease from the drive gears
- Use a brush or compressed air to dislodge filament debris from hobb teeth
- Avoid using wire brushes on the hobb teeth or gears.
Materials
- Heatsink: die cast aluminium (Direct)
- Extruder cover: MJF Nylon (Bowden)
- Gear/Hobb materials: stainless steel
- Fixings: steel
- Idler materials: Acetal
- Bearing elements: 2x shielded 623 bearings (drive shaft), Igus bushing.
Mounting Guidance
Hemera is mounted to a flat surface via the T-slots on the left or right sides of the motor. Typically Hemera is mounted onto the left side, as the air from the heatsink cooling fan exits on the right. If mounting on the right, ensure that sufficient space is left for airflow.
The screws must protrude 3mm±0.25mm from the mounting surface to go into the T-slots. The supplied M3×8 mounting screws are suitable for a nominal 5mm mounting plate thickness. Hemera must be mounted on a minimum of 2 mounting points, if using 2 mounting points, diagonally opposing points should be used, in order to ensure rigidity.
Volumes & Dimensions
Revo Hemera XS Direct drive
V6 Hemera XS Direct Drive
Bowden Hemera XS
Reference CAD
Compliance
Assembly Guide
| A. 1x Hemera XS extruder | F. 1x Revo Nozzle |
| B. 1x 4010 fan | G. 1x Thermistor extension cable |
| C. 2x Self-tapping screws | H. 1x Fan extension cable |
| D. 1x Spring | I. 1x Heater extension cable |
| E. 1x HeaterCore |
- Attach the spring to the groove on the bottom of the Heatsink.
- Attach the HeaterCore to the Hemera and spring assembly. (A slight twisting motion may be required.)
- Screw in the Nozzle, it should slide freely through the HeaterCore.
- Attach the fan to the Hemera HeatSink using the self-tapping screws.
The colour of the HeaterCore thermistor wire has changed from white to blue. If your HeaterCore has a white thermistor cable. Please refer to the diagram below:
- Attach the HotEnd extension cables.
Firmware
RepRap
Heater & Thermistor Values
- You need to add the following into your existing M308 command:
T100000 B4725 C7.060000e-8
If using the configuration tool:
Click on the Calculate Thermistor Coefficients button in the Heaters section, and select:
Semitec 104-GT2 (used by E3D)
from the drop-down menu.
Maximum Temperature
In config.g:
Locate the Heaters section and ensure the temperature limit is set to 300 degrees.
Make sure you change the temperature limit of your HotEnd and not your heated bed.
If using the configuration tool:
- Update your maximum temperature by going to the heaters tab and ensuring the option is set to:
300
Remember to restart your printer for your new values to come into effect.
- At this point it is a good idea to complete a PID tune so that we can heat up the extruder and check the motor direction is correct.
It is best practise to PID tune your heater after altering heater and thermistor firmware values or it may result in a heater fault.
Click on 'console' in the menu on the left of the duet interface. We will be using the 'Send code...' box to complete the PID tune.
Esteps
- Start by re-opening config.g. Look for the M92 command listed under 'Drives'.
replace 'E(your old number)' with 'E397'
- Remember to click the save icon and not the X when leaving config.g.
Motor Current
- Hemera is rated to 1.33A (1330mA) of current. Exceeding this may damage your Extruder.
- Open config.g, locate the motor currents line. The E(number) is the value for the extruder. Change this to 1000 to start with.
- 1000 mA should be sufficient. The lower the current, the more likely the extruder is to begin skipping steps. On the other hand, though, the higher the current, the hotter the motor will be to the touch. 1000 is a good balance to start with and can be adjusted further if you wish.
Motor Direction
- The final check is to make sure your motor is moving in the correct direction. You can find out if it's working correctly by heating up your HotEnd and trying to extrude some filament.
- If it is extruding when you press 'extrude' you are ready to print!
- If extrude and retract are the wrong way around, head back into config.g and return to the 'Drives' section.
- Look for a series of M569 commands, these control the drive direction of the motors in your printer.
- Below the M569 commands, you will find an M584 command. This is how you can identify which M569 command to modify.
- In this image, 'E' (Extruder) is mapped to drive 3 and so to reverse its direction, you would need to change the 'M569 P3 S0 command' to M596 P3 S1. (The P3 part refers to the drive number)
Marlin 2.0
Thermistor settings
- By using control-f in config.g update your settings to match:
#define TEMP_SENSOR_0 1
#define HEATER_0_MAXTEMP 300
#define HEATER_0_MINTEMP 5
Movement settings
- By using control-f in config.g update your settings to match:
#define DEFAULT_AXIS_STEPS_PER_UNIT { 80, 80, 400, 397 }
Extruder Motor Current
- By using control-f in Configuration_adv.h update your settings to match:
#define E0_CURRENT 1000