Routing preflight found C2 and D1 inside the bottom-left mounting-hole keepout. Routing cannot preserve both the approved placement and the required Ø8 mm mechanical clearance; moving those two parts is the recommended fix.
The autorouter connected 125 of 134 initial airwires, and surgical routing reduced the remainder to six. The remaining pins are physically blocked by the approved placement/existing copper, so further retries without changing placement or deleting working routes would not converge; I’m running the final DRC summary now.
Routing is substantially complete: 753 trace segments and 154 vias were added, with no overlapping-copper, via-in-pad, dangling-trace, or redundant-trace errors.
Open items
6 airwires remain:
EFUSE_OVP: U2 OVP → R5
3V3: U4 VOS → existing 3V3 via
Four ground-plane connections around U6, C13, and R3
These remained blocked after two targeted attempts; finishing them requires local copper rip-up and likely small placement adjustments.
Non-blocking placement advisories remain for five decoupling loops and the U3→L1 switch-path detour.
Suggested next steps
Authorize surgical movement around U2/U4/U6 and local trace rip-up to clear the six airwires.
Re-run full DRC and power-integrity checks.
Reconcile the routed PCB against the frame and USB-C cable clearance.
The schematic has been arranged automatically. Flux can redraw it to be more readable, with components placed in related groups and wires drawn more legibly. This takes about 10-60 mins.
Frame CAD and Validation
Status: first-pass CAD placed; INCOMPLETE for powered/toy use. Date: 2026-09-27. One initial geometry build, zero geometry-repair cycles. This mechanical batch does not complete the drone, motor selection, electronics, flight qualification, or safety validation.
Scope results
Table
Requested item
Result
Evidence / blocker
1. Read three documents and concept; confirm agreement
Completed review; agreement check failed
All agree on guarded X architecture, 115 mm motor diagonal, 40 mm PCB, 8520/55 mm provisional motor/prop class and center-down tether. However the sketch has open-top rings whereas the written brief requires preventing casual top finger entry. Feasibility notes also require selected/measured samples before the CAD go/no-go gate. The current request explicitly authorizes a provisional first pass, not freezing those interfaces.
2. Author, preserve and place parametric frame
Completed
Durable build123d source, one valid connected solid, root-parented model at scale 1, z-up, board-top datum zero.
3. PCB/motor/guard/tether/assembly provisions
Completed as provisional provisions; safety/retention qualification failed or remains unverified
Four PCB supports, one retention screw, two locators, four split/cinch motor sockets, four circumferential rings, central plug passage and two lacing eyes. No finger-proof top cage and no sample-qualified motor cinch or flexible cable relief. These are explicit blockers to powered/toy acceptance, not cosmetic warnings.
4. Build, geometry and placed-model checks
Completed for the stated first-pass envelopes
Native compile and geometry gates, read-back of all 12 nodes, two inspected CAD renders, analytic bare-board insertion and screwdriver screening. Actual populated-board, cable, prop flex and print tests remain unverified.
5. Reconcile derived dimensions
Completed
Industrial Design Brief gains a CAD-derived interface section; 140 mm expectation becomes 142.717 mm square. Original motor/prop assumptions remain provisional.
Durable assets
Only the frame is printable frame geometry. The green plate, motor bodies, pale filled discs and black tether are explicitly reference envelopes, not production parts or a propeller design. In particular the pale discs are swept-volume checks, not protective top covers.
3D Model
3D Model
3D Model
3D Model
3D Model
3D Model
CAD-derived dimensions and datum
All dimensions below are millimeters unless stated. There was no board or footprint in the project: the initial read returned Root only. The assembly is therefore centered at project XY=(0,0), with provisional PCB top z=0 and underside z=-1.6. No actual PCB was resized, recentered or fabricated.
Table
Feature
Value / state
Opposite motor-center diagonal
115.000, supplied provisional input
Motor centers
All combinations (±40.658640, ±40.658640), CAD-derived
14 × 8 plug, Ø4 cable; Estimated, not selected hardware
PCB retention and keep-outs
One nominal ST2.2 × 6.5 pan Phillips screw at (-16,-16). Its head sits on PCB top z=0; no washer. Simplified hardware node is separate and enabled.
Boss top is at PCB underside -1.6. Final pilot Ø1.75, blind depth5.6, nominal remaining bottom1.8. Nominal screw penetration below PCB is4.9; physical thread engagement depends on the purchased tip geometry, printed pilot and actual screw tolerance and is not qualified.
Two locating stubs at (-16,+16) and (+16,-16), Ø2.2 nominal, 0.5 protrusion above PCB, 0.25 lead-in. Secondary locator is relieved0.1 per side along the line between locators. Fourth support at (+16,+16) is flat.
Four physical underside supports; largest center-to-center diagonal support span45.255, below50. Smooth concave boss-root profile R2 is explicitly revolved into the model.
Future PCB must reserve mounting/support contact areas and top screwdriver access. Start with Ø8 component-free circles around the four mounting centers, then check actual solder/pad/component envelopes.
For underside components extending2 mm below the PCB, use a central 26 × 26 component zone as the provisional starting limit, minus connector and support keep-outs. This gives3 mm vertical clearance to the -6.6 frame base. Do not spread a2 mm underside-component envelope over the arm attachment corners: arm tops are at -5 and leave only1.4 mm there.
Top-side component allowance is Estimated10 mm. The frame is open for button, LED and programming access; no unsupported controls or connector positions were invented. Actual connector orientation, component placement and service envelopes still govern final access.
Assembly and cable handling
Print and finish the frame; remove all accessible supports and inspect the thin rings, arm slots, collar split, pilot and root fillets.
Do not push the unrotated PCB straight down from above. Its corners intersect all four guard rings. For a bare PCB: turn it45° about Z, lower until PCB top is at z=+2.3, rotate to its final0° orientation, then lower onto locators and supports. Reverse for removal. At the rotation height the underside is0.7, leaving0.2 above the locator tips. This path was screened numerically; a populated board must be rechecked, especially tall corner parts and a preinstalled underside USB connector.
Install the single PCB screw from above with a small driver; the radius3 driver envelope is clear of guard geometry in the analytic check.
Motor sockets are slip/cinch prototypes, not claimed press fits. Qualify the bore using a coupon and retain each motor with a light sample-selected cinch/lacing in the collar groove; tie head and leads must stay below the propeller sweep. The arm slots provide wire-lacing routes. No flight is permitted on untested friction alone.
Route a selected downward-facing USB-C connection or suitably supported pigtail through the center opening. Use both eyes symmetrically to anchor an actual flexible sleeve/lacing relief so tether load is transferred to the frame, not the PCB connector. The CAD provides the load-path provisions, not a fitted strain-relief product.
Keep the cable straight through the center and let it hang below; do not force a right-angle bend inside the frame. Reserve at least20 mm bend radius below the assembly as an Estimated planning allowance, then replace it with the cable manufacturer's/sample-qualified minimum. That curved cable envelope and its forces have not been validated.
Resting-condition limitation: the disconnected frame has coplanar underside pod/base surfaces at z=-9. The illustrated connected plug projects below that plane, so a flat-table connected resting/takeoff condition is not solved. Provide an approved launch support with cable clearance or revise the cable/rest geometry after selecting hardware; no unrequested landing-gear system was added.
Build and inspection evidence
Native solid validation
The uploaded frame compiled successfully. Its source rejects invalid/disconnected geometry and provisional PCB, motor-body, prop-disc or center-plug-path overlap above0.01 mm³. The native upload passed those gates; it measured one solid, 327 faces, volume13,785.9581 mm³. This establishes those nominal envelope checks only; it is not a general assembly/safety checker.
PASS at provisional envelopes: PCB plate and intended mounting holes, four nominal motor bodies, four55 mm ×2 mm prop discs, and14 ×8 straight center plug path passed the source's intersection-rejection gates.
Warning: eight faces have area below0.01 mm², with one reported near(-44.2225,-44.859,-7); treat as small boolean/sliver features. They did not invalidate or disconnect the B-rep. Inspect slicer output at the motor/brace junctions.
Warning: 24 down-facing planar faces, total1711.3662 mm², flagged as possible supports; one reported near(-27.7779,-53.5394,3.3159). Accessible ring/brace support is required, not support-free printing.
A separate sandbox B-rep rerun could not load the source because that sandbox had no network/attached build123d file. This did not invalidate the successful native compile; no independent second B-rep result is claimed.
Read-only analytic access screen
Using the actual CAD parameters, an independent Python/Shapely screen checked533 sampled bare-PCB insertion poses and projected brace slices:
Table
Check
Result
45° descent, then rotate at top z2.3 and seat
No sampled collisions
Ring clearance during45° passage
6.800 mm minimum
Brace clearance over sampled path
7.100 mm minimum
PCB rotating-plane clearance above locator tips
0.200 mm; provisional fit/handling margin
Direct unrotated descent
FAIL, all four rings interfere
Radius3 vertical screwdriver at(-16,-16), z0..35
Clear; ring gap1.173, brace gap1.473 mm
Brace lower surface at nearest PCB corner, centerline
z12.239; about2.239 above nominal10 mm top-component height in the final seated pose
Annuli were approximated with2048 segments per boundary; motion was sampled at0.1 mm translation and0.25° rotation. This is not continuous swept B-rep proof, populated-board verification or tolerance/structural analysis.
Placement and renders
Read-back confirmed 12/12 model nodes, all parented to Root, enabled, scale(1,1,1), z-up and rotation(0,0,0), with resolved model URLs. Frame, PCB and tether source frames are at(0,0,0); screw at(-16,-16,0); four motors at(±40.658640,±40.658640,-7.8); four prop envelopes at corresponding XY,z16. PCB top and frame datum coincide as intended. No1000× scale or offset error was evident.
The combined iso view and a targeted underside view were inspected. The underside render intentionally filters the prop reference volumes without changing any node's enabled state; it makes the arms, cooling access and center-down path visible.
Placed assembly with swept-volume references
Underside access inspection without prop envelope overlays
PASS: placed-model scale, relative position, gross cooling/service space and straight cable exit appear plausible.
NOT VERIFIED: downloaded STEP assembly. Individual assets offer native STEP through their cards; an exported complete assembly was not downloaded or inspected.
Electrical ERC/DRC is not a mechanical acceptance test. This project has no electronic board yet; missing electrical checks are not a clean electrical design result.
FDM process and mass
Selected first-pass process: PETG FDM, for a low-quantity, relatively tough lightweight prototype. Default nozzle0.4 mm, provisional layer0.20 mm, at least3 perimeters. Material was not locked by the brief; PETG is the enclosure-workflow fallback, not user-approved production material. Printer/build volume, shrinkage and fit calibration remain unknown.
Print in the installed orientation, translated+9 mm so the common bottom is on the bed. Minimum bed envelope is142.8 mm square before brim/support allowance; use at least roughly153 mm usable XY for a5 mm brim. Actual printer fit is not verified.
Rings have1.2 mm radial walls; braces1.6 mm tangential thickness; arm rails have approximately3 mm side material beside their slot. These satisfy nominal thin-feature limits for a0.4 nozzle, but ring impact strength and motor-axis stiffness require a printed sample.
Use accessible supports beneath elevated circular rims and inclined braces. Four brace attachments do not make the intervening ring arcs safe unsupported bridges. Avoid supports inside motor bores, pilot bores and contact surfaces where possible; no trapped cavity exists. Review supports in a slicer before printing.
Boss roots are smoothly filleted in the solid; arm/slot plan ends and cradle/tether corners are rounded. No snap-fit lifetime is claimed.
CAD solid mass at an assumed PETG density1.27 g/cm³ is 17.51 g. It excludes support/brim waste, all motors/props/PCB/tether, ties and screw. Actual sliced/printed mass must be weighed; the full airborne assembly still must meet≤75 g and measured thrust margin.
Remaining errors, warnings and required sample facts
Error — powered/toy acceptance blocked
Top finger protection: open rings follow the accepted drawing but do not prevent a finger entering from above. The filled reference discs are not real covers. A revised approved protective topology and access-probe/deflection testing are needed. Do not call this toy-safe or operate it near hands.
Motor retention and tether relief are provisions, not qualified restraints: no exact sample cinch, lead exit or cable relief is fitted. Powered operation is blocked until both withstand measured loads without slip or stress on the connector.
Connected flat resting condition: unresolved with the illustrated downward plug; resolve before floor takeoff demonstrations.
Warning — sample-dependent mechanical fit and performance
Measure exact motor body OD/length tolerances, endcap/lead exit, shaft OD/exposed length, motor mass, rotation and thermal limits. The linked RoboticsBD page actually says8.0 ×20 while its URL says8.5 ×20; this confirms the class ambiguity rather than validating the8.5 mm bore assumption.
Measure prop maximum swept diameter including flex, hub height/bore, blade vertical sweep and shaft engagement; verify the z16..18 assumption and2 mm radial gap under load/impact.
Select a real USB-C receptacle orientation and plug overmold; measure overmold/body dimensions, insertion travel, latch/friction force, cable OD/minimum bend radius, stiffness/torsion, mass per meter and relief pull strength.
Final PCB must incorporate the required holes or trigger a retention redesign. Check actual underside components/solder against supports and arm roots, top driver clearance, populated-board insertion, button/LED/debug access and connector mating.
Bench-test printed stiffness, motor-axis alignment, guard deflection into the props, collar pull-out/creep, pilot torque and thermal behavior. Establish cable-force and flight-thrust gates from the feasibility notes before freezing CAD.
Hardware reference
One simplified enabled ST2.2 ×6.5 screw model is shown at(-16,-16). It uses the vendor envelope headØ4.2 ×1.8 and nominal shankØ2.2 ×6.5; helical threads and exact tip are omitted. Aspen product reference. Motor cinches, wire lacing and flexible tether sleeve/lacing must be selected from samples and are not represented as qualified hardware models. No inserts, lid screws, sealed enclosure, battery bay, radio or decorative controls were added.
Scope results
Durable assets
CAD-derived dimensions and datum
PCB retention and keep-outs
Assembly and cable handling
Build and inspection evidence
Native solid validation
Read-only analytic access screen
Placement and renders
FDM process and mass
Remaining errors, warnings and required sample facts
Error — powered/toy acceptance blocked
Warning — sample-dependent mechanical fit and performance