# IRON-DAD — Systems design draft D01

**Status: proposed architecture plus unloaded CAD fit coupons. Not an electrical construction schematic, casting release, functional-safety design, or validated wearable.**

Website R03 presents geometry P01.4 and the R02 access concept without claiming a new mechanical pass. D01 adds service-routing and module concepts and three separate, non-structural CAD coupons. It does not alter or clear the original suit collisions.

## 1. Design inputs and non-negotiable boundaries

The intended wearer is Justin: 1930.4 mm stature (6 ft 4 in), just under 200 lb. The nominal digital mannequin has estimated proportions and girths, not measured limbs or a body scan. Actual mass is not simulated. The existing printed DaDave Mk6 at 110% is a reference, not an imported source for these new solids or a mandatory shape.

The intended finished design has thin cast exterior panels, a separate articulated support frame, overlapping joint covers, room for replaceable padding and accessible electronics, manual independent entry/exit, and a future replaceable AR module. The present model does not demonstrate those capabilities as a functioning suit.

Preserve the wearer, breathing space, approximate padding reserve, manual releases, direct sight, and full mechanism sweep before allocating service space. The existing 12 mm envelope is an approximate geometric reserve, not a prescribed pad thickness or demonstrated comfort. Added components must not silently consume that reserve. No cable, rigid channel or equipment pack belongs in an inner-elbow fold, actual armpit crease, throat crossing, rear-knee fold, seating pinch zone, or exit opening.

No load-bearing joint actuation, weapons, automated retention, autonomous motion, injury-oriented emitters, or remotely commanded wearer releases are included. The website is a static project presentation, not a control surface.

## 2. Proposed architecture and entry interfaces

The access concept is a supported rear frame with opening front/outboard panels. Captive compound hinges would first move panels clear of their overlaps, then swing them outward. Accessible over-center draw latches with secondary catches are candidate closures. These mechanisms, their retaining forces, their sequencing and a stable dressing stand are not designed or tested yet.

Normal dressing and emergency escape are separate requirements. Releasing the harness must not require disconnecting a loaded spring, dropping a metal panel, or operating software. A total electrical disconnect does not remove stored spring energy. Every service crossing needs a removal sequence that leaves mechanical escape available; opening the helmet must not depend on first finding a hidden connector.

## 3. Service atlas: functional routing reservations, not drilling coordinates

| Zone | Proposed route and function | Mandatory next review |
|---|---|---|
| H01 — helmet/collar | Removable local service lead outside the neck contact area; local sensors, fan and indicators. Future AR keeps manufacturer-supported power. | Head turns/nods; faceplate and helmet removal; camera fields of view; collar snag and strain relief. No loop encircling the neck. |
| B01 — rear bay | Removable controller/distribution tray, short local leads, accessible covers. | Cooling, back padding, shell access, independent harness release and balance. Rear maintenance access is not an inaccessible wearer release. |
| A01-L/R — arms | Outboard protected routing with flexible shoulder/elbow crossings and removable forearm control pods. | Spring and hinge sweeps, deep elbow flexion, reaching controls with the opposite hand, gloves and snag clearance. |
| P01 — power reservation | Candidate removable hip-area pack, source protection and reachable total disconnect. | Inert-mass fit study, sitting, pelvic doors, pack retention, insulation, thermal behavior and escape. Location is not fixed. |
| L01-L/R — legs | Minimal low-power visibility/diagnostics branches and guarded module disconnects. | Rear-knee folds, ankle motion, footwear entry, walking surfaces and foot-release behavior. |

No cable lengths or attachment coordinates have been derived from a complete moving mechanism. Wiring must be rerouted once those mechanisms are solved. Do not drill a primary member or machine a groove in it merely because a cable needs somewhere to go.

### Channel construction concept

Bolt-on or strap-mounted non-structural carriers are the starting proposal. Use removable lids, rounded or appropriately protected entries, insulated dedicated supply/return wiring, strain relief, and access to connectors. The cast shell and frame are not proposed as current return paths. Keep fastener ends and cable clamps away from the wearer. Metal construction alone does not establish grounding, bonding, insulation or EMC performance.

C01/C02 provides an 80 mm long, open-ended two-lane bench coupon, not a full-body cable tray. The central divider is a routing separator, not a certified electrical or thermal barrier. Cable diameters, dynamic bend radius, bundling temperature rise, fill fraction, abrasion and lid retention must be assessed with actual selected cable. The coupon has no claimed sealing or ingress rating.

At moving joints, provide a controlled flexible crossing supported on both sides. Neither arbitrary slack nor a taut harness is acceptable. The cable manufacturer's repeated-flex bend limit and off-body full-range cycle testing determine loop geometry. A cable must not act as a joint stop, panel tether or release lanyard.

## 4. Power domains — a proposal, not a connection-ready schematic

```text
Appropriate commercial protected battery module
  -> coordinated source protection + reachable total disconnect
     -> separately protected comfort branch: fans, local alerts
     -> separately protected regulated controller/sensor branch
     -> separately protected, hardware-disabled-by-default accessory driver branch
```

The accessory motion stop would remove only accessory motor power. Comfort and local alerts are intended to remain available on separate branches. The total disconnect removes ALL electrical power, including fans and alerts. A stalled or geared mechanism may remain stuck after de-energization; a mechanically usable release/disengagement path is a separate requirement.

Battery type, voltage, maximum current, fuse curves, conductor gauge, regulator ratings, disconnect rating, connector family, pinout, insulation and runtime remain **TBD**. The machine-readable schedule intentionally uses null for unselected electrical ratings. There is no certified safety controller in this draft. Source/branch protection must be coordinated for actual pack capability and wire/connector limits; a software current graph is not protection.

Use an appropriate commercial protected pack and its supported charging method. No DIY cell assembly, headset battery splice, body-worn charging procedure or unreviewed enclosure is supplied. Early tests use inert mass and then a current-limited supply off-body. Pack retention, venting and access require review before wearer trials.

## 5. Data and supervision

A local low-voltage controller with short sensor connections is the first bench concept. A differential wired bus may be evaluated if distributed nodes become necessary; no bus protocol, termination topology or connector pinout is selected. Do not stretch a board-level sensor bus around the body without evaluating signal integrity.

Local physical controls, deliberate enable/restart, stale-data indication and independent physical travel limits belong in the accessory concept. Driver faults, watchdogs and current sensing are diagnostic tools, not proof of functional safety. No cloud service or web UI controls movement, wearer retention or escape. Firmware, schematic, PCB and actuation code are not included.

## 6. Candidate sensing

- Air temperature/humidity near the helmet and torso paths; separate electronics/pack temperature channels. These are not core-temperature measurements or a medical clearance system. No operational stop threshold is selected here.
- Fan tach feedback; test blocked vents because rotating blades do not establish adequate airflow.
- Latch-position and accessory travel switches; position indication does not prove structural engagement or absence of a pinch point.
- Voltage/current diagnostics; source protection remains independent.
- IMUs for controlled-test logging and optional local advisories; no automatic fall locking or fall-arrest claim.
- ToF obstacle advisory through dedicated optical windows; test surfaces, lighting, clothing, covers and blind spots. Not collision avoidance.
- Temporary pressure mapping during fit work, with calibration and direct wearer feedback. Not a guarantee of tissue safety.
- Optional deliberate camera/microphone use with a visible recording indicator and physical privacy control. No covert recording or face recognition.

Specific TI and ST parts referenced on the site are capability examples, not selected purchases or a bill of materials.

## 7. Motor scope

Start with guarded cooling fans. Test flow paths, blockage, local override and failure off-body. Later, a faceplate or cosmetic vent can be a separate low-energy, counterbalanced bench study with captive parts, physical limits/guards, hold-to-run input and manual disengagement. No motor, linkage, torque, force or gear ratio has been selected. Cutting power to a geared drive is not equivalent to freeing it.

No leg/arm drive motors, powered retention latches, powered punches, automated body-joint locks or autonomous walking are part of D01. Passive assistance remains unresolved: the original direct elbow spring arrangement reverses assistance near 126 degrees and remains rejected.

## 8. Attachments and mounting interfaces

A01 is a generic 60 x 45 x 3 mm removable module backplate coupon with nominal 3.6 mm clearance holes and cable slots. It is not a battery mount, harness anchor, load-bearing dock, structural frame adapter or a proven quick-release. Standoffs, fasteners and pull-out ratings remain unselected.

Proposed future modules are an accessible rear controller tray, forearm control pod, guarded fan cassette, replaceable helmet sensor carrier and diffused visibility/comms modules. Every attachment needs a mass budget, local reinforcement review, retained hardware, contact-edge treatment, mounting strength and full-motion/removal tests. Do not hang heavy hardware from an unreviewed cosmetic casting. Keep visibility lighting non-dazzling; no respirator or hazardous-atmosphere claim for a fan/filter cassette.

## 9. Future AR helmet

No HoloLens is currently owned or required. An intact donor should be evaluated first, with its optical/sensor relationships and manufacturer-supported power preserved. Reserve replaceable carriers and possible optical windows rather than promising to shrink waveguides or extend proprietary cables. Direct vision, ventilation and manual helmet opening must work without AR.

The HUD on the website is explicitly simulated. Its sample battery and air-temperature values are not live measurements or defined safe limits. Intended eventual functions are local battery/airflow/status notices and communications—not targeting or automatic movement. HoloLens 2's published servicing horizon is a reason to keep any display module replaceable, not a prediction that the headset will stop operating on that date.

## 10. Evidence and next acceptance gates

1. Measure the wearer and refine the opening/escape mechanism first. Account for gloves, grip orientation, latch travel and operating force—not only point reachability.
2. Inspect printed C01/C02/A01 coupons with calipers and actual de-energized cable samples. No full suit print or casting needed.
3. Add inert module masses to an adjustable mock-up, then test every intended movement and opening sequence. Inspect cable and contact space throughout the path.
4. Bench-test actual selected electrical parts, wiring protection, fan blockage, stalled accessories, sensor loss, controller reset and total disconnect. Record real values and limits before human use.
5. Review mechanical stored energy, load path, instability, pressure/heat and escape independently. Initial wearer trials need supervision even though the eventual goal is independent use.

These are proposed gates, not completed tests. Actual D01 evidence is limited to valid single CAD solids, watertight mesh exports and zero base/lid BREP intersection in the nominal assembled position. No fatigue, load, thermal, wear, cycle, electrical, clinical or casting trial was performed.

## Primary references

Source review for Web R03: 2026-09-20. These sources describe technologies and hazards; none certifies this project.

- Microsoft hardware: https://learn.microsoft.com/en-us/hololens/hololens2-hardware
- Microsoft servicing: https://learn.microsoft.com/en-us/hololens/hololens-release-notes
- NIOSH wearable hazards: https://www.cdc.gov/niosh/bulletin/2017/exoskeletons-construction.html
- NIOSH heat stress: https://www.cdc.gov/niosh/heat-stress/about/index.html
- TI current-feedback driver example: https://www.ti.com/product/DRV8876
- ST ToF sensor example: https://www.st.com/en/imaging-and-photonics-solutions/vl53l1x.html