External, not invasive
The concept adds a motor, line, and anchor outside the shade rather than altering the headrail.
Reversible · local-first · staged
Add motion.
Keep the shade.
A build plan for an external winch that is intended to lift a cordless cellular shade without modifying its internal mechanism. Start with one window, prove each gate, then decide whether to repeat it.
- No cloud account required by the design
- No original shade disassembly planned
- No physical performance claim made here
motor
anchor
12 V control
Directional diagram only. Clearances, force, retention, temperature, line behavior, and safe failure modes require measurement on the actual installation.
One before three
Print and qualify one complete unit before purchasing or fabricating the remaining quantity.
Evidence before confidence
Software output and generated STL files are inputs to testing, not evidence of a safe installation.
System map
Six blocks. One controlled motion.
The planned architecture keeps high-level automation separate from the low-voltage hardware at each window. The public guide intentionally omits household network details and credentials.
-
01
CommandSchedule, local interface, or physical button
-
02
ESP32Commands position and reads the required top endstop
-
03
TMC2209 driverProduces current from the STEP/DIR interface
-
04
Motor + spoolConverts rotation into line travel
-
05
Lift lineTransfers motion to the bottom rail
-
06
ShadeMoves only after fit and load gates pass
Prototype boundary
The repository contains a proposed ESPHome configuration and open-loop position model. It does not contain retained evidence of installed endstops, measured repeatability, thermal qualification, or a completed three-shade run.
Bill of materials
Buy for one. Reserve for three.
Quantities below reflect the repository design, not a live stock check or purchase authorization. Confirm electrical ratings, dimensions, reviews, and delivery immediately before ordering.
| Part | Specification to verify | One-unit gate | Three-unit total |
|---|---|---|---|
| NEMA 17 motor | 42 × 42 × 38 mm; 1.5 A; 42 N·cm; 5 mm D-shaft | 1 | 3 |
| TMC2209 STEP/DIR driver | Stepstick format; 12 V compatible; current limit set before motion | 1 | 3 used from a 5-pack |
| ESP32 development board | 30-pin ESP32-WROOM-style footprint | 1 | 3 |
| Protected 12 V DC adapter pack | UL-listed; 2 A target; correct polarity; female 5.5 × 2.1 mm barrel screw terminals included | 1 supply + 1 included terminal | 3 used from a 5-pack |
| LM2596 buck converter | Adjustable output; set and measure 5.0 V before load | 1 | 3 used from a 5-pack |
| Solderless breadboard + jumpers | Bench validation only; never the installed final assembly | 1 shared bench setup | 1 shared kit |
| FR-4 prototype board | 50 × 70 mm solderable board for the installed control box | 1 | 3 used from a mixed kit |
| Permanent low-voltage wire | 22 AWG stranded, color-coded; terminate and insulate every joint | As required | 1 shared six-color pack |
| Electrolytic capacitor | 100 µF, 25 V minimum; observe polarity | 1 | 3 + spares |
| Braided lift line | Thin, high-strength, non-loop installation | About 1.4 m | 1 spool |
| KW12-3 top endstop | Roller limit switch; required physical upward stop and re-zero input | 1 | 3 used from a 10-pack |
| M2 × 16 machine screws + M2 flat washers | cSeao B0BD2CXW7D; signed-in check July 30, 2026: $8.99, 4.4/5 from 72 reviews, listed for July 31 delivery | 2 screws + 4 washers | 6 screws + 12 washers |
| M2 nylon lock nuts (nyloc) | MroMax B07YV8D6HG; signed-in check July 30, 2026: $5.59, 4.7/5 from 134 reviews, listed for July 31 delivery | 2 nuts | 6 nuts |
| Local push button | Prewired 12 mm momentary control | 1 | 3 used from a 5-pack |
| M3 motor hardware | Screws, nuts, and washers matched to motor and printed interfaces | 1 set | 1 shared assortment |
| #8 × 1¼-inch wood screws | Use only in verified sound wood; choose substrate-specific anchors otherwise | After substrate check | As installation requires |
| #6 × ½-inch pan-head screws | Bottom-rail interface only after material and engagement check | 2 | 6 |
| Ballast material | Incremental mass only after controlled descent testing | 200–400 g trial range | Up to 1.2 kg trial stock |
Shared supplies
PETG filament, a multimeter, solder, heat-shrink, a USB data cable, cable management, and eye protection support all units.
Final assembly boundary
The solderless board proves the circuit on the bench. Installation requires the 50 × 70 mm FR-4 board, 22 AWG wire, and the KW12-3 endstop.
Cost is provisional
The signed-in three-shade build-pack check on July 30, 2026 recorded $220.56 before tax—$3.46 below the prior $224.02 snapshot. Treat that as time-stamped planning data, not a standing quote.
Fabrication
Six STL files. One integrated endstop mount.
The regenerated motor bracket includes the KW12-3 mounting tab and 9.5 mm hole spacing, so no seventh adapter is required. Settings remain starting points until a retained slicer report and physical fit test pass.
Structure + required endstop
Motor bracket
- Batch
- 1, then up to 3
- Material
- PETG target
- Start
- 4 walls · 40% infill
- Orient
- Side / gusset face down
- Includes
- Integral KW12-3 mount
Motion
Spool
- Batch
- 1, then up to 3
- Material
- PETG target
- Start
- 4 walls · 40% infill
- Orient
- Hub up
Load
Anchor tray
- Batch
- 1, then up to 3
- Material
- PETG preferred
- Start
- 3 walls · 15% infill
- Orient
- Flat
Electronics
Control box
- Batch
- 1, then up to 3
- Material
- PETG preferred
- Start
- 2 walls · 15% infill
- Orient
- Flat
Electronics
Control lid
- Batch
- 1, then up to 3
- Material
- PETG preferred
- Start
- 2 walls · 15% infill
- Orient
- Flat
Routing
String guide
- Batch
- As routing requires
- Material
- PETG target
- Start
- Dense / solid-ish
- Orient
- Flat
Before batch printing
Slice → inspect → print → fit → load-test
- Confirm all parts fit the selected printer volume.
- Inspect thin walls, holes, seams, the integrated endstop tab, and support assumptions in layer preview.
- Print one complete kit and record material, profile, mass, and time.
- Reject cracking, creep, poor shaft fit, or fastener pull-through before installation.
Staged assembly
Every phase earns the next.
This sequence converts the repository concept into a validation plan. Stop on any unexpected heat, noise, movement, line behavior, looseness, or software state.
-
01
Measure gate
Confirm the actual shade and mounting envelope
Record shade type, travel, at least 50 mm of head clearance, nearby heat, outlet path, and child/pet access. Identify the substrate before choosing fasteners.
Exit evidence: dimensioned sketch, substrate identification, and chosen mount location. Use #8 wood screws only in sound wood. -
02
Print gate
Fabricate and inspect one six-file kit
Test the 42 × 42 × 38 mm motor pilot and holes, 5 mm D-shaft bore, fasteners, enclosure clearances, integral KW12-3 mount, and line path.
Exit evidence: accepted part photos, dimensions, slicer report, and rejection notes. -
03
Electrical gate
Bench-test low voltage with no shade attached
Verify polarity, set the converter to 5.0 V before the controller is connected, and set TMC2209 current with no line attached. Prove the circuit on a solderless board, then transfer the accepted design to 50 × 70 mm FR-4 with 22 AWG wire.
Exit evidence: measured rails, current setting, inspected solder joints and insulation, temperatures, and emergency-stop method. -
04
Mechanical gate
Dry-fit the mount, spool, line, and anchor
Keep power disconnected. Check straight line travel, sharp edges, fastener engagement, clearance, and a loop-free route.
Exit evidence: full manual travel without rubbing, snagging, or fixture movement. -
05
Motion gate
Run bounded low-speed travel with a spotter
Start with a short move and immediate power access. Increase travel only after reviewing line winding, mount motion, motor heat, and skipped steps.
Exit evidence: repeatable short travel followed by 25 supervised cycles, then a 250-cycle endurance gate. -
06
Control gate
Require the physical endstop, then test recovery
Verify the KW12-3 stops upward motion and re-zeroes independently of step counting. Then test restart, loss of communications, loss of power, manual intervention, and re-zero.
Exit evidence: retained endstop-actuation and recovery logs across repeated full cycles. -
07
Replication gate
Decide whether to build units two and three
Repeat only after the first installation meets the project’s safety, reliability, noise, thermal, and usability criteria.
Exit evidence: signed go/no-go decision and frozen configuration.
Non-negotiable
Treat motion, line, heat, and power as hazards.
This is a DIY electromechanical prototype, not a certified window-covering product. A qualified adult must review the installation, and the system must remain inaccessible to children and pets.
No loops
Use one straight, guarded line. Never create a reachable loop or entanglement point.
Guard pinch zones
Keep hands, fabric, and objects away from the spool, line, anchor, and moving bottom rail.
Separate from heat
Keep electronics, adapters, and cable insulation away from radiators, direct heat, and trapped sun load.
Use listed power
Use a correctly rated, safety-listed low-voltage adapter. Measure converter output before connecting electronics.
Prove the mount
Use #8 × 1¼-inch wood screws only in verified sound wood. Choose substrate-specific anchors otherwise; validate any adhesive separately.
Keep a hard stop
Maintain immediate access to disconnect power during every prototype test. Do not test unattended.
Validation register
Visible unknowns are a feature.
The checklist below is deliberately conservative. Mark an item complete only with retained evidence from the actual hardware and installation—not because a model, drawing, or simulation looks correct.
| Gate | Current status | Required evidence |
|---|---|---|
| Parametric CAD source | Source present | Regeneration log and geometry review |
| STL exports | Six files present | Slicer review, printed dimensions, integral endstop mount, and fit checks |
| Firmware configuration | Draft present | Bench logs on the selected board and driver |
| Permanent FR-4 interconnect | Not documented | 50 × 70 mm board, 22 AWG wiring, insulation, and enclosure inspection |
| Required KW12-3 endstop | Mount source present | Switch fit, upward stop, re-zero, and fault tests |
| Single-shade motion | Not documented | Bounded motion and recovery test record |
| Mount retention | Not documented | Static load, creep, fastener, and inspection results |
| Thermal behavior | Not documented | Motor, driver, enclosure, adapter, and ambient measurements |
| Line and entanglement review | Required | Installation-specific hazard review |
| Three-unit repeatability | Not documented | Matched configuration and repeated cycle data |
Questions before fabrication
Build only what the evidence supports.
Is this a finished motorized-shade product?
No. It is an open prototype plan. It has not been represented here as certified, production-ready, or physically validated.
Will it fit every cordless cellular shade?
No fit claim is made. The actual headrail, bottom rail, spring balance, travel, clearances, structure, and heat exposure must be measured.
Should all three units be ordered and printed immediately?
No. The lowest-risk path is one motor channel, one print set, one shade, and a defined test record before replication.
Does the public guide include remote-access setup?
No. Network identifiers, credentials, and household infrastructure are deliberately outside this privacy-safe public guide.
Are the cost and print estimates guaranteed?
No. They are planning values from the source notes. Re-slice the current files and re-price the exact approved parts before committing.
The practical next move
Prove one clean, bounded motion.
That single result is more valuable than three boxes of unverified parts.