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13. Mechanical and Machine Design

Week Assignment

Machine Design (part 2 of 2)

Group assignment:

  • Actuate and automate your machine
  • Document the group project

Individual assignment:

  • Document your individual contribution

Learning outcomes

  • Work and communicate effectively as a team
  • Design, plan and build a machine
  • Analyse and solve technical problems
  • Recognise opportunities for improvements in the design

Have you answered these questions? - Documented the machine building process to the group page

  • Documented your individual contribution to this project on your own website

  • Linked to the group page from your individual page as well as from group page to your individual pages

  • Shown how your team planned, allocated tasks and executed the project (Group page)

  • Described problems and how the team solved them (Group page)

Listed possible improvements for this project (Group page)

  • Included your design files (Group page)

  • You need to present your machine globally and/or include a 1 min video (1920x1080 HTML5 MP4) + slide (1920x1080 PNG) (Group page)

Studied Topics

Group and Individual Assignment

Automatic Smart Roller Blinds Mod

Group assignment idea was to create the Automatic Smart Roller Blinds Mod, where the servo rotates the chain to raise and lower the shade.

makerworld - finniminni @finniminni - finniminni had 3D design of the Automatic Smart Roller Blinds Mod.

There were given the following components:

- Roller Blinds
- Nema 17 Stepper
- ESP32 Board as Controller (I used a tiny ESP32-C3)
- Stepper Driver (A4988 or TMC2209) - I recommend the TMC, as they are way more quiet
- 7x M3 countersunk screw
- 12V Power Supply
- Step Down Converter 
- Wiring

The stepper driver and ESP’s connection:

- Stepper Driver    Connected to
- DIR Pin   ESP32 - GPIO5
- STEP Pin  ESP32 - GPIO6
- SLEEP Pin ESP32 - GPIO21
- VIN   Power Supply +
- GND   Power Supply -
Also hook up the Step Down Converter to supply 5V to your ESPs 5V Pin

A parametric 3D design for an automatic roller-blind chain drive was done on a Fusion 360. Its stl files are here

STL1 , STL2 , STL3

The roller-blind chain had the three different assembly parts: a base plate with mounting slots, a cylindrical motor cradle, a clamp bracket, and a bead-chain sprocket.

This image showed an exploded view of a compact gearbox/enclosure: internal ribs, two spur gears, a front plate, and a stepper motor aligned on one shaft axis. This helped me to understand the the visuals, that communicate how the printed parts, gears, and motor come together to grip and drive a roller-blind bead chain.

Then the design was sent to a Bambu Lab X1-Carbon 3D printer with two filament bays.

After the size adjastment, the 3D-printed parts and assembly of a roller-blind chain motor mount was reprinted. As shown here, we had three parts: the white base plate with elongated wall slots, an orange clamp piece, a printed sprocket, and two screws.

Then the motor was mounted to the base, the orange clamp locks it in place, and the wiring exits to the right, and three screws secure the clamp and sprocket hub, aligning the motor shaft through the center opening. The cylindrical motor pocket and the bead-chain sprocket positioned were ready to use.

We installed the motorized roller-blind module installed on a operating window, where the printed white base is wall-mounted near the blind bracket, while the orange clamp holds the motor and bead-chain sprocket in line with the chain. The bead chain drops neatly over the sprocket, indicating proper engagement and tension.

Overall, the motorized roller-blind module enabled automatic raising and lowering of the shade.

We made a prototype test setup for the motorized roller-blind module. The bench power supply was stacked on the windowsill with 12 V. As illuminated LEDs showed that the circuit was powered and active.

Overall, the motorized roller-blind module demonstrated the stable work.

Then, the following excution parts of our assignment were demonstrated at

Yryszhan’s page

Learning outcomes

For this week’s Mechanical and Machine Design, We used a parametric Fusion 360 model of a blind-roller actuator (editable gear module, shaft diameters, hole spacing, and clearances), designed a spur-gear train with a cam/chain interface, and sized a stepper with reduction to meet required torque and speed with a safety margin. We applied design-for-additive-manufacturing choices (orientation, fillets, wall/infills, built-in supports, and fit tolerances), printed and post-processed parts, and assembled a modular baseplate with slotted holes for alignment and chain tensioning. We integrated the electromechanics by wiring the stepper driver and bench supply, setting current limits, and verifying motion, homing, and repeatability. I installed the module on a real roller blind and measured travel, smoothness, backlash, and slippage, iterating to improve chain engagement and mounting rigidity. I conducted reliability and safety checks for pinch points, fastener loosening, and motor/driver thermal rise, adding guards where needed. I documented CAD, BOM, assembly steps, and test results, and reflected on improvements for the next revision (gear wear, enclosure, and limit sensing).