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Welcome to the 3MS Documentation

The 3MS is short for MMMS, which stands for Modular Multi Material System

Discord Shield

The 3MS is a simple, compact, modular, reliable, budget-friendly multimaterial system.

Get Started

Why 3MS?

Why use the 3MS when there are many other multi-material systems?

Here are a few reasons:

  • Simplified Design: Minimal mechanical complexity for increased reliability.
  • Low Cost: A 4-filament-unit 3MS can be built for ~$150 USD
  • Easily Sourceable: All the parts for the 3MS are available on Amazon.
  • Comprehensive Documentation: Step-by-step guides to ensure smooth setup and operation.
  • Scalable: Easily expand the system to handle any number of filaments.

Requirements

To use the 3MS, your setup has to meet the following requirements:

  • Run Klipper firmware
  • Have SSH (PuTTY) access (99.9% of Klipper installations have this, and if you don't you really should setup SSH)
  • Have one spare USB port
  • Have an adapter to install a PTFE tube to the inlet of your printer's extruder.

Get Started

To get started with the 3MS, see the Master Instructions.

Get Started

Sample Prints

Model: Sheep by Cipis

Model: Monolith Cryptic Calendar by Sevro

Model: Voron Cube (bundled with OrcaSlicer), painted by me in OrcaSlicer

Printed at 50% scale

Model: T-rex by Cipis

Model: Striped lizard with pupils by EngMike

West3D Video Series

Thank you to Allen Rowand from West3D for making this ongoing series on the 3MS.

Comparison of Multimaterial Systems

Not sure if you want to use the 3MS? Check this comparison between several common multimaterial systems.

  • 3MS Modular Multimaterial System for Klipper 3D Printers

    Pros:

    Simple Design

    Reliability

    Documentation

    Modular Design

    Active Community

    Price (~$140)

    Cons:

    Compatibility (only Klipper)

  • Box Turtle MMU Automated Filament Changer

    Pros:

    Reliability

    Active Community

    Documentation

    Cons:

    Compatibility (only Klipper)

    Complexity

    Price ($300)

  • ERCF v2 An expandable MMU for Klipper-based 3D-printers

    Pros:

    Reliability

    Modular Design

    Active Community

    Documentation

    Cons:

    Compatibility (only Klipper)

    Complexity

  • TradRack by Annex Engineering

    Pros:

    Reliability

    Modular Design

    Active Community

    Documentation

    Cons:

    Compatibility (only Klipper)

    Complexity

  • 3DChameleon MK4 Automatic Color Changer

    Pros:

    Compatibility

    No custom firmware

    Price ($200)

    Cons:

    Reliability

    Documentation

  • SMuFF Smart Multi Filament Feeder

    Pros:

    Reliability

    Modular Design

    Documentation

    Cons:

    Complexity

  • Prusa MMU3 Multi Material Upgrade

    Pros:

    Reliability

    Support

    Documentation

    Cons:

    Compatibility

    Price ($300)

Master Instructions

Due to the modularity of the 3MS, there are many ways to set it up. This guide attempts to encompass all supported ways of setting up the 3MS.

Basic Steps

The basic steps this guide will follow are:

  1. Getting a BOM
  2. Assembling your 3MS
  3. Configuring your 3MS
  4. Calibrating your 3MS

0. Explanations

Before starting the instructions, a basic understanding of how the 3MS works is recommended. There are two types of components in the 3MS:

  • Controller

    This controls the 3MS stepper motors. This is usually an extra 3D printer mainboard purchased specifically for the 3MS. If your existing 3D printer mainboard has spare stepper ports, you can use them for the 3MS.

    The available configurations are specific to either an external mainboard setup, or utilizing spare stepper ports on your existing mainboard. If you are utilizing spare stepper ports, the name of the config will include "(main MCU)"

    "controller" can be used interchangeably with "MCU" and "control board"

  • Filament Units

    These move the filament. These are standard MK8 extruders (used on Ender 3's). You can use different extruders for the filament units, as long as you can mount them securely and they can attach to a PTFE tube. MK8 extruders are used as the default due to their low cost.

    "filament unit" and "gate" can be used interchangeably

The number of filaments you will be able to print with is equal to the number of filament units you have. For example, two filament units will let you print with two colors. It is important to note that one filament unit will NOT let you print in multimaterial.

1. Getting a BOM

Go to BOM to view the bill of materials for the number of filament units you want. Example BOM for two filament units and a SKR Mini E3 V2:

Name Price Quantity Link Notes
SKR Mini E3 V2 $34.99 1 Amazon
Duponts $9.99 1 Amazon These wires are only sufficient to run steppers, not heaters
12V PSU $7.39 1 Amazon This PSU is only sufficient to run steppers, not heaters
NEMA17 Stepper Motor $9.99 2 Amazon You can use a pancake stepper if you want, but it will have less torque
MK8 Metal Extruder $9.99 2 Amazon
Capricorn PTFE Tubing $11.49 1 Amazon You likely won't need this for every unit, as this is usually too long for only one unit

2. Assembling your 3MS

Follow Assembly to assemble your 3MS.

3. Configuring your 3MS

Set up Happy Hare firmware following this guide.

If you're looking for a configuration, see generator guide.

Next, configure Happy Hare firmware using this guide.

4. Calibrating your 3MS

After installing and configuring Happy Hare, the 3MS requires some calibrations. Follow Calibration to calibrate your 3MS.

Setup ↵

BOM

Controller Choice

First, choose the control board you want to use in your 3MS. Choose a controller from the available ones here.

Number of filament units

First, choose the number of filament units you want. Each filament unit lets you print with an additional filament. Two filament units are the minimum. You can add or remove filament units after building, but the BOM and configuration will vary based on how many filament units you want.

Controller BOMs

Choose the BOM for your chosen controller from the list below:

Recommended: BTT MMB

Other Controllers

BTT SKR Mini E3 V2

BTT SKR Pico

Mellow Fly D7

BTT Octopus (main MCU)

Zonestar ZM384 (main MCU)

Mini RAMBo

Geetech A30T

Filament Unit BOMs

For each filament unit, purchase this BOM:

Name Quantity Price Link Notes
NEMA17 Stepper Motor 1 $9.99 Amazon You can use a pancake stepper if you want, but it will have less torque
MK8 Metal Extruder 1 $9.99 Amazon Alternatively, you can use this Dual-drive MK8 based extruder
PTFE Tubing 1 $8.99 Amazon You likely won't need this for every unit, as this is usually too long for only one unit

BTT MMB

Max filament units: 4

MCU Name: 3ms

BOM

Name Price Quantity Link Notes
BTT MMB $34.99 1 BTT
Duponts $9.99 1 Amazon These wires are only sufficient to run steppers, not heaters
12V PSU $7.39 1 Amazon This PSU is only sufficient to run steppers, not heaters

Wiring

Route the wires from the NEMA17's to the controller board. Follow this table to determine which port to plug the motors into:

Filament Unit # Motor Port
0 M1
1 M2
2 M3
3 M4

Now, grab your 12V PSU and two M-M duponts, one red and one black (M-M means that there is metal coming out of both ends of the cable). Plug the PSU into the wall, but don't plug the screw terminals into the PSU (the screw terminals have green)

  1. Plug the red wire into the positive terminal of the screw terminals

  2. Plug the black wire into the negative terminal of the screw terminals

    Danger

    These dupont cables are too thin to run much more than the stepper motors. If you run a heater or other power-intensive device off of the MMB board, the duponts and/or PSU can melt/catch fire. To reduce the risk of this, you can double up on the duponts or get thicker wires.

  3. Following this image, locate the HVIN and GND inputs (top left)

  4. Route the two wires inside closest to the HVIN and GND inputs

  5. Using the markings on the board, plug the red wire into the HVIN terminal on the MMB
  6. Using the markings on the board, plug the black wire into the GND terminal on the MMB

  7. Plug in the VUSB jumper

  8. Verify all connections

    Warning

    If the wires are plugged into the wrong place, or swapped polarities, your MMB, Stepper motors, and/or PSU can be badly damaged.

  9. Plug the PSU screw terminals into the PSU wire

Plug the MMB into your Klipper host with the cable that came with it.

If the MMB lights up, you wired it correctly!

Controllers

Follow this guide to determine which controller to use in your 3MS.

Options

The 3MS works on multiple different controllers.

Info

If your printer's mainboard has spare stepper ports, you can use them to control 3MS steppers. You can open an issue on Github (there's a template) to get a configuration made for your specific setup. Any controllers listed with "(main MCU)" use those spare stepper plugs.

Choose one of the following supported controllers (a checked box indicates it is fully tested, and an empty box indicates testers wanted):

BTT SKR Mini E3 V2

Max filament units: 4

MCU Name: 3ms

BOM

Name Price Quantity Link Notes
SKR Mini E3 V2 $34.99 1 Amazon
Duponts $9.99 1 Amazon These wires are only sufficient to run steppers, not heaters
12V PSU $7.39 1 Amazon This PSU is only sufficient to run steppers, not heaters

Wiring

Route the wires from the NEMA17's to the controller board. Follow this table to determine which port to plug the motors into:

Filament Unit # Motor Port
0 XM
1 YM
2 ZAM or ZBM
3 E0M

Now, grab your 12V PSU and two M-M duponts, one red and one black (M-M means that there is metal coming out of both ends of the cable). Plug the PSU into the wall, but don't plug the screw terminals into the PSU (the screw terminals have green)

  1. Plug the red wire into the positive terminal of the screw terminals

  2. Plug the black wire into the negative terminal of the screw terminals

    Danger

    These dupont cables are too thin to run much more than the stepper motors. If you run a heater or other power-intensive device off of the SKR board, the duponts and/or PSU can melt/catch fire. To reduce the risk of this, you can double up on the duponts or get thicker wires.

  3. Following this image, choose either the DCIN or POWER input

  4. Route the two wires inside closest to your chosen input
  5. Using the markings on the board, plug the red wire into the positive terminal on the SKR
  6. Using the markings on the board, plug the black wire into the negative terminal on the SKR

  7. Verify all connections

    Warning

    If the wires are plugged into the wrong place, or swapped polarities, your SKR, Stepper motors, and/or PSU can be badly damaged.

  8. Plug the PSU screw terminals into the PSU wire

If the SKR lights up, you wired it correctly!

Finally, plug the SKR into your Klipper host with the blue cable that came with it.

BTT SKR Pico

Max filament units: 4

MCU Name: 3ms

BOM

Name Price Quantity Link Notes
SKR Pico $35.99 1 Amazon
Duponts $9.99 1 Amazon These wires are only sufficient to run steppers, not heaters
12V PSU $7.39 1 Amazon This PSU is only sufficient to run steppers, not heaters

Wiring

Route the wires from the NEMA17's to the controller board. Follow this table to determine which port to plug the motors into:

Filament Unit # Motor Port
0 X
1 Y
2 Z1 or Z2
3 E

Now, grab your 12V PSU and two M-M duponts, one red and one black (M-M means that there is metal coming out of both ends of the cable). Plug the PSU into the wall, but don't plug the screw terminals into the PSU (the screw terminals have green)

  1. Plug the red wire into the positive terminal of the screw terminals

  2. Plug the black wire into the negative terminal of the screw terminals

    Danger

    These dupont cables are too thin to run much more than the stepper motors. If you run a heater or other power-intensive device off of the SKR board, the duponts and/or PSU can melt/catch fire. To reduce the risk of this, you can double up on the duponts or get thicker wires.

  3. Following this image, locate the POWER input

  4. Route the two wires inside closest to the POWER input
  5. Using the markings on the board, plug the red wire into the positive terminal on the SKR
  6. Using the markings on the board, plug the black wire into the negative terminal on the SKR

  7. Verify all connections

    Warning

    If the wires are plugged into the wrong place, or swapped polarities, your SKR, Stepper motors, and/or PSU can be badly damaged.

  8. Plug the PSU screw terminals into the PSU wire

If the SKR lights up, you wired it correctly!

Finally, plug the SKR into your Klipper host with the blue cable that came with it.

BTT Octopus (main MCU)

Warning

This configuration may not work with the BTT Octopus Pro.

Max filament units: 4

MCU Name: main

main MCU

This configuration is a main MCU configuration, meaning that your printer should already be running off a BTT Octopus and you don't need to purchase one.

BOM

Per filament unit:

1x TMC2209 ($7 each)

Wiring

Route the wires from the NEMA17's to the controller board. Follow this table to determine which port to plug the motors into:

Filament Unit # Motor Port
0 MOTOR7
1 MOTOR6
2 MOTOR5
3 MOTOR4

Einsy RAMBo (main MCU) with SKR Mini E3 V2

Danger

This guide is an expert guide only

Info

This modification is designed for the Prusa MK3/S/S+, and depends on this Klipper configuration.

Why?

When printing fast, the TMC2130's on the Einsy RAMBo can get quite loud. The TMC2209's on the SKR Mini are much quieter and support denser microstepping.

BOM

Name Price Quantity Link Notes
PSU -> Einsy Cable $7.99 1 PartsBuilt3D
Stepperonline NEMA17 $9.99 each Amazon 2 Replaces current XY motors

Wiring

First, unplug the 3MS steppers from the SKR Mini, and the XY steppers from the Einsy RAMBo. The motors will need to be switched due to different connector types between boards.

This table outlines the major wiring of this modification.

Einsy RAMBo SKR Mini E3 V2 Motor
PSU+ POWER+
PSU- POWER-
XM 3ms0
YM 3ms1
XM X
YM Y

Configuration

In your printer.cfg, comment out these lines:

printer.cfg
1
2
#[include klipper-prusa-mk3s/mk3s/steppers.cfg]
#[include klipper-prusa-mk3s/mk3s/tmc2130.cfg]

Next, copy the contents of 3ms/controllers/einsy_rambo_with_skr_mini/xy-motors.cfg and ze-motors.cfg to klipper-prusa-mk3s/skr/xy.cfg, and klipper-prusa-mk3s/mk3s/ze.cfg, respectively.

Add the following new lines:

printer.cfg
1
2
[include klipper-prusa-mk3s/skr/xy.cfg]
[include klipper-prusa-mk3s/mk3s/ze.cfg]

Restart Klipper.

Zonestar ZM384 (main MCU)

Max filament units: 3

MCU Name: main

main MCU

This configuration is a main MCU configuration, meaning that your printer should already be running off a ZM384 and you don't need to purchase one.

Filament Unit # Motor Port
0 E0
1 E1
2 E2
3 E3

Mini RAMBo

Max filament units: 4

MCU Name: 3ms

BOM

Name Price Quantity Link Notes
Mini RAMBo 1
Duponts $9.99 1 Amazon These wires are only sufficient to run steppers, not heaters
12V PSU $7.39 1 Amazon This PSU is only sufficient to run steppers, not heaters

Wiring

Route the wires from the NEMA17's to the controller board. Follow this table to determine which port to plug the motors into:

Filament Unit # Motor Port
0 XM
1 YM
2 ZAM or ZBM
3 E0M

Now, grab your 12V PSU and two M-M duponts, one red and one black (M-M means that there is metal coming out of both ends of the cable). Plug the PSU into the wall, but don't plug the screw terminals into the PSU (the screw terminals have green)

  1. Plug the red wire into the positive terminal of the screw terminals

  2. Plug the black wire into the negative terminal of the screw terminals

    Danger

    These dupont cables are too thin to run much more than the stepper motors. If you run a heater or other power-intensive device off of the RAMBo board, the duponts and/or PSU can melt/catch fire. To reduce the risk of this, you can double up on the duponts or get thicker wires.

  3. Route the two wires inside closest to your chosen input

  4. Using the markings on the board, plug the red wire into the positive terminal on the RAMBo
  5. Using the markings on the board, plug the black wire into the negative terminal on the RAMBo

  6. Verify all connections

    Warning

    If the wires are plugged into the wrong place, or swapped polarities, your RAMBo, Stepper motors, and/or PSU can be badly damaged.

  7. Plug the PSU screw terminals into the PSU wire

If the RAMBo lights up, you wired it correctly!

Finally, plug the RAMBo into your Klipper host with the cable that came with it.

Mellow Fly D7

Max filament units: 7

MCU Name: 3ms

BOM

Name Price Quantity Link Notes
Mellow Fly D7 1
Duponts $9.99 1 Amazon These wires are only sufficient to run steppers, not heaters
12V PSU $7.39 1 Amazon This PSU is only sufficient to run steppers, not heaters

Wiring

Route the wires from the NEMA17's to the controller board. Follow this table to determine which port to plug the motors into:

Filament Unit # Motor Port
0 X
1 Y
2 Z
3 Z1
4 Z2
5 E0

Now, grab your 12V PSU and two M-M duponts, one red and one black (M-M means that there is metal coming out of both ends of the cable). Plug the PSU into the wall, but don't plug the screw terminals into the PSU (the screw terminals have green)

  1. Plug the red wire into the positive terminal of the screw terminals

  2. Plug the black wire into the negative terminal of the screw terminals

    Danger

    These dupont cables are too thin to run much more than the stepper motors. If you run a heater or other power-intensive device off of the board board, the duponts and/or PSU can melt/catch fire. To reduce the risk of this, you can double up on the duponts or get thicker wires.

  3. Using the markings on the board, plug the red wire into the positive terminal on the board

  4. Using the markings on the board, plug the black wire into the negative terminal on the board

  5. Verify all connections

    Warning

    If the wires are plugged into the wrong place, or swapped polarities, your board, Stepper motors, and/or PSU can be badly damaged.

  6. Plug the PSU screw terminals into the PSU wire

If the board lights up, you wired it correctly!

Finally, plug the board into your Klipper host with the cable that came with it.

Geetech A30T

Contributed by @ImChrono

Max filament units: 7

MCU Name: 3ms

BOM

Name Price Quantity Link Notes
Geetech A30T $34.99 1 Geetech
Duponts $9.99 1 Amazon These wires are only sufficient to run steppers, not heaters
24V PSU $7.39 1 Amazon This PSU is only sufficient to run steppers, not heaters

Firmware

To flash Klipper firmware to the A30T, run the following command and see the following screenshot:

1
2
cd ~/klipper
make menuconfig

Next, connect the BOOT0 jumper on the A30T and run:

1
stm32flash -i ',,,,,' -v -w out/klipper.bin -g 0 /dev/serial/by-id/<your-mcu-id-here>

Wiring

Route the wires from the NEMA17's to the controller board. Follow this table to determine which port to plug the motors into:

Filament Unit # Motor Port
0 X
1 Y
2 Z0
3 Z1
4 E1
5 E2
6 E3

Now, grab your 12V PSU and two M-M duponts, one red and one black (M-M means that there is metal coming out of both ends of the cable). Plug the PSU into the wall, but don't plug the screw terminals into the PSU (the screw terminals have green)

  1. Plug two red wires into the positive terminal of the screw terminals

  2. Plug two black wires into the negative terminal of the screw terminals

    Danger

    These dupont cables are too thin to run much more than the stepper motors. If you run a heater or other power-intensive device off of the motherboard, the duponts and/or PSU can melt/catch fire. To reduce the risk of this, you can double up on the duponts or get thicker wires.

  3. Route the four wires inside closest to your chosen input

  4. Using the markings on the board, plug the two red wires into the positive terminal on the motherboard
  5. Using the markings on the board, plug the two black wires into the negative terminal on the motherboard

  6. Verify all connections

    Warning

    If the wires are plugged into the wrong place, or swapped polarities, your motherboard, Stepper motors, and/or PSU can be badly damaged.

  7. Plug the PSU screw terminals into the PSU wire

If the motherboard lights up, you wired it correctly!

Finally, plug the motherboard into your Klipper host with the cable that came with it.

UART Conversion

⚠️ Attention: Proceed with Caution! ⚠️

This modification involves delicate hardware changes that require precision and attention to detail. Mistakes in wiring or soldering can permanently damage your GTM32_103_V1 board.

  • Double-check connections before applying power.
  • Use proper tools and follow best practices for soldering.
  • If you are not confident in your skills, seek assistance from an experienced individual or professional.

You proceed at your own risk.

Overview

This guide details the process of modifying the GTM32_103_V1 3D printer controller board to enable UART capabilities. The GTM32_103_V1 board features 7 TMC2208 drivers operating in standalone mode by default. This modification involves removing the SD card slot and repurposing its pinouts for UART communication.

Features of the Modification

  • UART Capability: Enables communication with TMC2208 drivers via UART repurposing the SDCard slot

Hardware Changes

Components Modified

  • SD Card Slot: Removed entirely to free up pinouts for UART.
  • Repurposed Pins: SD card slot pins are reassigned as per the following table:
TCM2208 Driver SD Card Pin STM32 Pin
Motor0 9 PC7
Motor1 8 PC9
Motor2 7 PC8
Motor3 5 PC12
Motor4 3 PD2
Motor5 2 PC11
Motor6 1 PC10

Procedure

  1. Remove Pull down resistor from each driver:
  2. Desolder the SMD 1kΩ resistor carefully to avoid damaging the surrounding components.
TMCDriver PCB Code
Motor0 R53
Motor1 R57
Motor2 R62
Motor3 R120
Motor4 R71
Motor5 R95
Motor6 R105
  1. Remove the SD Card Slot:
  2. Desolder the SD card slot carefully to avoid damaging the surrounding components.
  3. Repurpose the Pinouts:
  4. Rewire the SD card pins according to the table above.
  5. Connect each pin to its corresponding UART connection for the TMC2208 drivers.

Testing and Validation

After completing the hardware changes: 1. Connect the board to your 3D printer and power it on. 2. Use your firmware to verify UART communication with each TMC2208 driver. 3. Check for successful responses from the drivers using a terminal or debugging tool.

Photos

Add your photos here to demonstrate the modification process and results: - Close-up of the TMC driver WIN_20241111_22_06_27_Pro

-Close-up of the TMC driver with resistor removed (solder the uart pint to the red signed pin) WIN_20241111_22_15_44_Pro

  • Close-up of the SD card: WIN_20241111_22_05_02_Pro

  • Rewired pins with labels. WIN_20241116_22_14_33_Pro

UART Configuration

When configuring this board with Happy Hare firmware, be sure to use UART-mmu.cfg and UART-mmu_hardware.cfg (renaming to mmu.cfg and mmu_hardware.cfg respectively).

Ended: Controllers

Assembly

Follow this guide to assemble your 3MS.

Printed Parts

Mounting

  • Univeral M3 Mount for Extruder Note that this requires 2-4 M3 bolts and a place to screw the bolts into (like an aluminum extrusion with T-nuts). Designed by 3DCoded.

  • 3MS Box This is designed for four filament units and a BTT MMB. Designed by chadakken.

Y-Splitters

Filament Units Assembly

  1. If using any mounting parts, place it on the face of your NEMA17 motor.
  2. Assemble the MK8 extruders using the instructions that came with them.
  3. Repeat for all filament units.

Wiring

Note for Certain Printers

If your printer has Klipper running internally (not on an external computer like a Raspberry Pi), the controller (if not a main MCU config) is plugged into a USB port on the printer itself.

Follow one of the following guides based on your controller:

Recommended: BTT MMB

Other Controllers:

Calibration

Follow this guide to calibrate your 3MS.

Original Documentation

This guide is a simplified version of the official Happy Hare documentation. I highly recommend you read it as it contains useful information and goes more in detail if you are having trouble with the calibrations.

Verify Filament Sensors

Before calibrating, it is important to ensure that your filament sensors are working properly.

Run in your Klipper console:

1
QUERY_ENDSTOPS

and verify the output. For each endstop, open means no filament detected, and TRIGGERED means filament present. Re-run the command several times, inserting/removing filament to each of the sensors, to verify that each filament sensor properly detects filament.

Gear Steppers

First, calibrate your gear steppers (filament units). The goal of this calibration is to ensure the filament actually moves as far as expected.

First, detach the PTFE tubing from each of the filament units.

For each filament unit (gate), repeat the following steps:

  1. Manually load filament until it sticks out slightly from the end of the filament unit
  2. Cut the tip of the filament to be flush with the PTFE coupler (side cutters are good for this).

  3. Run the following commands in your Klipper console:

    1
2
    MMU_SELECT GATE=n
MMU_TEST_MOVE MOVE=100

    where n is the gate number you are calibrating (starting at zero).

  4. The filament should move forwards. If it moves backwards, invert your gear stepper. Measure the distance the filament moved out of the extruder. Using side cutters the same as before can be helpful for this. Run the following command in your Klipper console:

    1
    MMU_CALIBRATE_GEAR MEASURED=n

    where n is the measured distance.

  5. Repeat step c. The filament should move exactly 100mm.

Encoder (if installed)

If you are using an encoder, like a BTT SFS (Smart Filament Sensor), you need to calibrate your encoder.

  1. Load your filament manually to its parking position at the start of the Y-splitter.

  2. Run in your Klipper console:

    1
    MMU_CALIBRATE_ENCODER

Inverting a Gear Stepper

If you notice any of your gear steppers moving filament in the opposite direction as expected, you need to invert the gear stepper. There are two options to do this:

  • Physically flip the stepper cables
  • Invert it in software

To invert a gear stepper in software, open mmu_hardware.cfg and invert the dir_pin for the respective stepper.

Example, if T1 is moving backwards:

mmu_hardware.cfg
1
2
3
[stepper_mmu_gear_1]
...
dir_pin: mmu: PC5
mmu_hardware.cfg
1
2
3
[stepper_mmu_gear_1]
...
dir_pin: !mmu: PC5 # <-- Note the ! in front of mmu

Tip

If the pin already has a ! in front of it, remove it to invert it.

Restart Klipper.

Ended: Setup

Guides ↵

Configuration Generator

Follow this guide to create a custom configuration for your 3MS.

Base Configuration

First, find the case configuration for your mainboard. The best place to find these is in the official Klipper sample configurations.

In this example, a BTT SKR Mini E3 V3 will be used. A base configuration is available in the official configuration here.

Raw File

Now you have the configuration, but it isn't a raw file. It's a full webpage. To continue, you need the raw configuration. To do this, find the "Raw" button in the upper-right corner of the page.

Now, you will be redirected to a page with the raw configuration. Copy the URL.

Generating the Configuration - Web

Generating the Configuration - Shell

Now that you have the raw URL, you need to install the generator script.

Installation

  1. Clone the 3MS repository:

    1
2
    cd ~
git clone https://github.com/3DCoded/3MS

  2. Ensure Python 3 is installed (not Python 2).

  3. Install requests

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    pip3 install requests

Running the Script

First, start the script:

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cd ~/3MS
python3 generator.py

Now, you will be presented with several options.

Configuration URL

Paste in the URL you found earlier.

Local file configurations

You can also use a file configuration by passing the --file parameter:

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python3 generator.py --file

Selected Steppers

The script will now list all the stepper motor configurations that were found in the configuration, with a number next to each. Enter the desired steppers, seperated by spaces.

TMC Drivers

For each stepper you selected, the script will ask you which TMC driver to use. For the SKR Mini E3 V3, there is only one option: TMC2209.

No TMC Drivers?

If you don't want to use TMC drivers in your configuration, pass the --no-tmc parameter:

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python3 generator.py --no-tmc

MCU Name

Finally, the script will ask you for the name of the MCU controlling your 3MS. Follow the naming convention outlined in the prompt.

Your configuration will now be available in ~/3MS/mmu.cfg and ~/3MS/mmu_hardware.cfg.

3DChameleon to 3MS Conversion

Follow this guide to convert a 3DChameleon to a 3MS.

BOM

Name Price Quantity Link Notes
BTT MMB $34.99 1 BTT
Duponts $9.99 1 Amazon These wires are only sufficient to run steppers, not heaters
24V PSU $12.99 1 Amazon This PSU is only sufficient to run steppers, not heaters
MK8 Metal Extruder $9.99 2 Amazon Alternatively, you can use this Dual-drive MK8 based extruder

The final cost of this upgrade is around $70.

Instructions

  1. Release the eight bolts on the 3DChameleon unit to remove the two NEMA17 stepper motors.
  2. Unplug the NEMA17's from the 3DChameleon electronics board
  3. Remove the PTFE tubes from the 3DChameleon unit and the Y-splitter

Next, follow the Master Instructions except for the BOM section.

Ended: Guides

Contributing ↵

Contributing

If you want to contribute to the 3MS project, follow the instructions below.

Development Setup

Follow Development Setup to setup your system for development with the 3MS.

Pull Request

Finally, submit a pull request. A developer will get back to you soon with feedback, before merging your pull request into the main project.

Thank you for your contribution to the 3MS project!

Development Setup

Follow this guide to setup your system for development with the 3MS.

Documentation Changes

  1. Fork the 3MS repository
  2. Create a new branch for your pull request (from the docs branch)
  3. Install Python.
  4. Install Pipenv.
  5. In your terminal, navigate to the 3MS folder, and run: 
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    pipenv install
pipenv shell
  6. Develop changes in the new branch, using the following command to run the documentation locally: 
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    mkdocs serve

Ended: Contributing