Smart Orbiter v3.0 summary


Smart Orbiter v3.0, a brand new innovative all in one dual drive extruder.

The main mission of this design is the integration o the well proven Orbiter v2 concept into a lightweight all in one smart extruder.

Why smart? This is the first extruder with integrated electronics. Together with Klipper, it is an awesome combination, I guarantee!

 1. Features and performance

This brand new all in one extruder design with many cool features we call Smart Orbiter v3.0  is one of my latest and finest extruder design made in collaboration with LDO Motors. The extrusion system concept and mechanical performances are similar to the Orbiter v2.0 but completely redesigned from scratch.

Summary of the coolest features

ü Pure plated copper heat-block with 72W ceramic heater and Bontech CHT nozzle for highest possible weight VS flow ratio;

ü Heat-break performance optimized with finite elements analysis for extreme temperature gradient to ensure clogless free printing experience;

ü Unique tensioning mechanism with elastic predefined tension levels

ü Frameless recessed 24V fan to reduce the extruder weight and outside dimension

ü Large RNC coated dual drive gears with planetary gear reduction, similar to orbiter v2.0

ü New precision main shaft design to reduce gear eccentricity

ü Full aluminum housing with Delrin plastic gears for low noise and long lifetime

ü The smart feature – integrated electronics

ü Easy remove system of the secondary drive gear for easy cleaning and maintenance

ü Double filament exit guide system for best TPU printing performance

ü Overall weight is 175g

SO3 specification

ü Drive type: 12mm dual drive extrusion system

ü Weight: 175g including standard hotend

ü Nominal steps / mm (16x micro stepping): 690

ü Rotation distance: 4.69

ü Extrusion force: 6.5Kg+

ü Gear ratio: 7.5:1

ü Max stepper current: 0.85A RMS (1.2A peak), derating over 50°C ambient temperature.

ü Min stepper current: 0.55A RMS (0.75A peak) for operation up to 70°C ambient temperature

ü Heater temperature sensor type: ATC Semitec 104NT-4-R025H42G

ü Extruder fan: 24V frameless fan with speed signal

ü Maximum operating temperature: 90°C (with motor current derating down to 0.55A RMS)

ü Filament sensing

ü Filament unload

ü Hotend lit

ü Filament input lit – RGB LED WS2812B type

ü Extruder temperature senor: 100K NTC Generic 3950

ü Smart features supply: 3.3V or 5V

Read more about the design features here


New 72W ceramic heater with Bondtech CHT nozzle for highest flow/weight ratio.

Very short distance between drive gears and heat-block (17.7mm)

Screw mounted thermistor for best thermal contact (104NT-4-R025H42G - Optional PT1000

Easy and fast nozzle + heat-block swap – single screw release


 Bimetallic heat-break

Heat-break made out of stainless steel tube with 0.25 mm wall thickness for lowest heat transfer.

M7 heat-block mounting screw - compatible with V6 heat-block styles

Bi-metallic heat-break together with the heatsink optimized for highest temperature gradient using finite element analysis.

heatsink sim 1

 Wire strain release

Stainless steel wire strain release feature to avoid wire brake issues of the heater and thermistor wires.

Shape optimized for bad thermal transfer to reduce thermal losses.

strainrelease sim

 Quick nozzle change

Quick nozzle change optimized for best thermal performance implies a simple swapping of the heat-block retained by one single screw.

Heater and thermistor wires connected via microfit connectors for easy electrical disconnection.

 High Flow

Best optimized weight vs flow ratio thanks to Bondtech CHT nozzle, flow rate 35-40 mm3.

Note: Actual flow depends on the filament type, nozzle temperature and size. The picture exemplifies a typical behavior measured using SUNLU PLA @ 210°C. The figure shows performance results using standard V6 plated copper nozzle, Bondtech CHT 0.4mm and 0.6mm.

center guide

 Double filament guide

For good TPU printing experience its important that there is no gap left between the drive gears and exit guide where the filament could escape.

The two guarding features, center and side  leads to no physical space where even the most flexible filament can escape.

The center guide stops filament to be chewed in between the drive gear tooths.

The side guides stops the filament to be chewed into the gap between the drive gears.

 Filament Tensioning

Filament tensioning lever with three predefined positions: open, L1 (soft) and L2 (hard). 

No need to guess anymore the correct tensioning, the predefined positions ensure repeatable and always correct tensioning.

The elastic tensioning arm makes sure the tensioning is independent from filament diameter and avoids filament deformation due to over-tensioning.


 Secondary drive gear

Secondary drive gear easy remove feature for easy cleaning and maintenance. 

The secondary drive gear together with the tensioning arm can be removed simply by removing one M3 screw.

 Precision mainshaft

Redesigned octagonal shaped precision aluminum main shaft.

The outer diameter of the shaft is slightly bigger than the inner diameter of the bearing and the main drive gear. The octagonal shape allows slight deformation of the aluminum shaft to match the exact inner diameter of the bearings and the drive gear, therefore reducing any eccentricity to a minimum.

o3 electronics

 Integrated electronics

Integrated electronics, the smart features:

ü Filament sensing and auto load

ü Filament auto unload

ü RGB LED lit filament input

ü White LED hotend lit

ü Extruder temperature sensor

ü ESD and short circuit protection

ü Optimized for Klipper

 Outside Dimensions

Total weight of 175g.

  3. SO3 Firmware configuration

Expand here

  3.1 Basic configuration

  • Steps: 690 steps/mm @ 16 micro-stepping

  • Rotation Distance: 4.69

  • Pressure advance: ~0.015s - to be calibrated

  • Retraction: 0.5~1.0mm - to be calibrated

  • Retraction speed: 120mm/s, reduce it to 30mm/s when printing TPU

  • Motor current: 0.85A RMS (LDO-36STH20-1004AHG)

  • Max. acceleration: 8000 mm/s*

  • Normal motor operating temperature: 65-75°C

  • Drive motor with stealth chop disabled!

* The extruder itself without filament can handle acceleration up to 25000mm/s2. Adding weight of the filament it drags along its recommended to set max acceleration below 8000mm/s2. To reduce clicking noise of the extruder (due to fast direction change) you may limit acceleration to 3000mm/s2

  3.2 Klipper extruder configuration


step_pin: Pxx                                     #define correct port number

dir_pin: !Pxx                                       #define correct pin number

enable_pin: !Pxx                                 #define correct pin number
microsteps: 32

full_steps_per_rotation: 200

rotation_distance: 4.69                          #includes gearing ratio

nozzle_diameter: 0.4                              #define nozzle diameter

filament_diameter: 1.750

max_extrude_only_distance: 500

max_extrude_only_velocity: 120

sensor_type: ATC Semitec 104NT-4-R025H42G  

sensor_pin: Pxx                                    #define correct port number

pullup_resistor: 4700

min_temp: 0

max_temp: 350

pressure_advance: 0.015

pressure_advance_smooth_time: 0.03

min_extrude_temp: 170

smooth_time: 0.5


control = pid




[tmc2209 extruder]
uart_pin: Pxx                                
#define correct pin number

interpolate: true

run_current: 0.85 #**

sense_resistor: 0.11 #**

stealthchop_threshold: 0

driver_TBL: 0

driver_HEND: 6

driver_HSTRT: 7

driver_TOFF: 4

**Very important note!!! Please make sure the sense resistor is set according to what you have on board. TMC2130, TMC2208 and TMS2209 usually have 0.11, TMC2660 have 0.051 and TMC5160 have usually 0.075

As an example, if you set by mistake the sense resistor to 0.11 instead of 0.051 the real current of the motor will be more than double, and the power injected in the motor more than four time higher, yes you read it correctly FOUR - AKA 4 times higher. 0.85A shall give a power loss of about 3.5W doubling the current will lead to >14W - this will melt all the plastic gearset before you even notice something is wrong!

How you can identify the sense resistor? It’s pretty easy, look for two identical resistors which are bigger than all the others onboard or around the stepper driver. See the examples in the next pictures. 

Resistor marking examples: R110 means 0.11, R075 means 0.075Ω, R051 means 0.051Ω;

Sometimes I also doubt myself if the setting I'm playing with really sets the current and not something else does. Here is what I do to make sure I’m doing it right:

Set the current to a very low level 0.1-0.2A. Command extrusion, you should see the extruder turns but it skips steps very easy. This means you are tingling the right configuration, then set it to what it should be and check motor temperature, should not exceed 75°C running at room temperature. If yes you might have misconfigured something (shunt / sense resistor) causing higher motor current than you believe.

  3.3 Integrated Smart Features

Internal electronics smart features are: 

ü Filament sensing & auto load

ü Filament auto unload

ü RGB LED lit filament input

ü White LED hot-end lit

ü Extruder temperature sensor

o3 electronics
Orbiter 3.24 Smart LDO PCB front

Pinout of the internal electronics connector is the following:

Orbiter 3.24 Smart LDO connector 1

1 - Hot-end lit
2 - Extruder temperature - 100K NTC
             Generic 3950
3 - Filament Unload
4 - Filament Sensing
5 - Filament input lit - WS2812B
6 - +5V
7 - GND

The correct pins to which the Smart Orbiter signals are corrected must be defined first. It can be done very simple by defining the correct port names in the [board_pins SMARTORBITER3] section from the beginning of the configuration file. Please do not change the pins alias name! Make sure you replace "Pxx" with your port name to which the signals are connected.


Be aware there is a bug in Klipper in case you use pin aliases to other micro pins than main. Even if the mcu pin alias is defined like:

 filament_sensor_pin = toolboard.PA2 or 

 filament_sensor_pin = rpi:gpiochip0/gpio23

Klipper still reference them to the main micro. To fix this for me moment the only possibility is to add the mcu name before the pin alias call in the macros.

Similar to this: toolboard.filament_sensor_pin.

Update printhead parking position X and Y to match your printer needs. You can enable disable features in the macro configurable sections.


Include the "SmartOrbiter.cfg" file into the beginning of your printer.cfg.


  3.4 Motor current vs extruder performance and temperature

First let me repeat that stepper motors are running hot by design. Is not uncommon to run stepper motors at temperatures over 100°C. Actually, designs in which the stepper motor does not run hot are the bad ones / heavily overengineered. And do not worry, nothing will happen to your stepper running hot. You will not extend its lifetime by running it at lower current and cooler.

The stepper used in the Smart Orbiter design is rated to 180°C. Of course, you should not run it that hot. The limit of the Orbiter max temperature is limited by the plastic DuPont Delrin gears with temperature deflection rating up to 120°C. 

Concluding all these limits the orbiter stepper temperature shall not exceed 100°C at any conditions.

See the attached graphs defining the Smart Orbiter v3.0 (for LDO36STH20-1004AHG) performance based on motor current.

orbiter accel 2

  4. SO3 Tool-board

Expand here

Should a tool-board magic smoke come out because of user error? Why?

Should a tool-board be destroyed by a fault in your 3D printer? Why?

My answer is NO! And this is what this tool-board is all about!

We are hobbits, professionals and let’s face it, we do mistakes, and when the magic smoke shows up everybody is disappointed, even if we know it’s a user fault. In this board, I promise you the magic smoke is kept inside extremely tight!

  4.1 Features

Smokeless Features

·         Optimized for Smart Orbiter v3 shape and features

·         STM32F042 microcontroller running on 48MHz

·         Automotive USB communication to Raspberry PI

·         Onboard LIS2DW12 accelerometer

·         TMC2209 extruder stepper driver

·         Direct connection to SO3 integrated board

·         1x PWM controlled part fan outputs

·         DC-DC converter based Hot-end fan driver, compatible with 12/24V fan types with RPM speed input signal

·         Hot-end temperature sensor input compatible with standard NTC or PT1000 temperature sensor types

·         I/O for bed level sensor

·         X-Stop sensor input

·         Onboard temperature sensor

·         Advanced thermal management

Protection Features 

·         Active short circuit protected Hot-end output

·         Active short circuit protected fan driver outputs

·         Active Protection circuit against reverse power supply connection

·         Protection against loss of GND supply

·         Analog and digital inputs protected against short to +24V supply voltage

·         USB data lines protected against short circuits to GND and +24V

·         EMI interference and ESD protection an all inputs and outputs

·         Heater protection against short between heater lines and sense thermistor GND pin

  4.2 SO3 Tool-board Block diagram

  4.3 Pinout definition

LDO ordered some new parts manufactured out of spring steel (65MN) and sent me 3 parts for testing. I assembled than on my extruder samples and I hit another setback. One of the tension blades broke in two.

  4.4 SO3 Tool-board electrical wiring


  4.4 SO3 Tool-board user manual

  5. Assembly instructions

Expand here

  5.1 Hotend assembly

For correct hotend assembly please follow the following video:

Tips & Tricks:

1) It is not mandatory to put thermal paste over the nozzle and the hotend parts. It is mandatory for the cold side, part of heat-break which is inserted in the extruder.


2) Make sure the heat-break is inserted first into the heat-block first!  Fasten the screw, make sure the strain release plate is in correct position - failing to make this step correctly will cause filament to leak out over the hotend top side or through the sensor thread.


3) After heat-break is in place insert the nozzle, fasten it in place - no need for hot fastening! Hot fastening is only needed if there is molten plastic inside, hot heat-block allow plastic to be squeezed out from between the nozzle and heat-break to ensure correct sealing thus avoid leaky hotend.


4) Handle the heater with care. Its ceramic and can be broken very easily. Do not grab it with plyers or something hard. Always fasten nozzle / heat-break while holding the copper part of the heat-block.

  5.2 Frameless fan


·       Red -> +24V

·       Black -> GND

·       Yellow -> speed signal

Supply the fan with 24V. To reduce the noise generated by the fan, it's speed can be reduced to 60% without affecting the extruder performance. In case is used in enclosed chamber with temperature over 60°C the fan shall run at 100%.


Download Smart Orbiter Klipper configuration file here! - Last update: 23.02.2024, version: 2.2.05

Download SO3 Tool-board user manual here! - Last update: 16.02.2024, document version: 1.4

  7. Adapters  Mounts

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Collection of mounts, adapters for Orbiter v3.0 extruder designed by our 3D community members. A big thanks to all of them, we all appreciate your work!

The list will grow as new adapters are designed, in case I missed some please contact me via our Facebook support group.

To link you project I have a few minimum requirements:

·       The solution shall be proven and verified.

·       Provide a nice rendered picture or a nice picture of the setup you are proud of.

·       Link to where the design is stored.

  Orbitron Cube

This is the cooling and mounting solution of the Orbitron 3D printer.

Uses an L shaped aluminum mounting part which holds the SO3 and the belts.

Part cooling uses two 12cm side blowers and a deflector fixed to the SO3 which redirects air downward towards the printed part.

For more details check out the Orbitron cube webpage!

  Railcore II ZL X LDO Smart Orbiter V3 & Euclid probe mount

A great adapter design for Railcore II, designed by Yves from Fractalengineering.

Railcore mount

Beltender adapter for Ender 3 V2 with MGN12 X gantry

Complete toolhead designed using SO3 for the Beltender. The toolhead should be compatible with most of the ender v2 MGN12 upgrades.

*Note: This design is not fully tested, its still under beta testing, but its a good start and idea sharing project of how the SO3 could be mounted on a bedslinger printers.


A Smart Orbiter v3.0 mount for BLV MGN Cube. Features: Klicky Probe | 3DO camera nozzle +LED light | BTT EBB36 canbus.

All credits goes to Jeffrey Lai!


BLV MGN Cube Metal kit

Mount for smart orbiter 3 for the metal BLV cube DC42 IR bed probe. 2 cooling fan options: rear 7530 and dual front 5015.

All credits goes to Chriss Bright!

blv metal

E3D Tool changer

Adapter plate to replace an E3D v6 or E3D Hemera XS with a Smart Orbiter V3.0 on Tool changer printer.

All credits goes to Max Stein


Creality Ender 7

Adapter design for Ender Creality Ender 7.

All credits goes to Nicolas Correa


Detachable front 5015 fan

Mounting plate adapter for BIQU B1 to SmartOrbiter v3.0 with fun duct similar to original one.

All credits goes to Martin Fuska!


Detachable front 5015 fan

5015 fan mount for Smart Orbiter v3, includes exchange system. This is a great design based on my ender adapter and fun duct which could be compatible with any printer types.

All credits goes to Nicolas Correa