# Orchard Series 1 — P1 engineering-development brief

15 September 2026 · Lead: 24U / 1000 mm / mesh / freestanding on disc feet

## Release status

**M1 viewer addendum:** Casters now visualizes industrial 100 mm twin wheels, reinforced mounting/subframe envelopes and separate polished leveling feet. The new goal is 500 kg equipment payload plus actual cabinet weight during controlled indoor repositioning as well as stationary support; no rolling rating is established. Rolling/Parked geometry adds 145/155 mm below the body. This mobility development is not included in the feet-based P1 scoped STEP or costed BOM below. No fabrication release is implied; supplier fit, joints, support polygon, brakes, leveling, mounting cutouts and dynamic/stability testing remain open.

**Not released for fabrication, loading or installation.** The user selected a **500 kg equipment payload design target**. No working-load rating, complete cabinet mass, thermal capacity, wall-anchor rating or compliance certification is established. P1 hardens the shared construction and provides a scoped mechanical CAD starting point and budget. It does not replace a responsible mechanical/electrical engineer or a fabricator's controlled drawings.

The 12U, 24U and 48U remain one design family: same 600 mm shell width, top radius, finish language, rail interface, steel sections, skin gauge and hardware strategy. Lengths and the number of intermediate ties change through one parameter rule. A 24U result does not qualify the other sizes. No 500 kg suspended-wall or rolling rating is implied.

## Design intent retained

- Rounded satin gray aluminum shell, broad 41 mm outer top radius, flush mesh/glass appearance, slim polished front/rear perimeter, polished side symbols and 98 mm disc-foot appearance.
- Removable sides retain the curved top return and nominal 1.2 mm crown seams. The lower 28 mm rolled sill is now fixed; the removable panel ends 30 mm above the body bottom, leaving a 2 mm lower reveal. This permits a 12 mm vertical lift followed by outward withdrawal without the old under-cabinet return scooping into foot hardware.
- The lower 10 mm return has 20 mm relief at each depth end. Attached stiffeners, latch, keepers and bonding are separate design features, not assumed to work simply because the exterior skin clears.
- A discreet 10 mm satin release cap is retained at the upper rear. Its custom interface to the commercial concealed actuator still needs a stroke/force/retention prototype. It is not a completed push-to-release product.

## Shared structural architecture

Coordinates: millimeters; X right, Y up, Z front; origin at body center. Body heights remain 650 / 1180 / 2250 mm for 12 / 24 / 48U. Reference depths are 800 / 1000 / 1200 mm; the explorer keeps the prior depth options.

| Item | Shared design-development definition |
|---|---|
| Corner posts | Four 40 × 40 × 3 mm steel RHS; X ±264; Z ±(D/2 − 55); cut length U×44.45 + 4 |
| Crossbars | Four 40 × 40 × 3 mm RHS; 568 mm X length; Y ±(U×44.45/2 + 22); Z at posts |
| Depth ties | 30 × 40 × 3 mm RHS; X ±269; cut length D − 150; equal Y stations with span no greater than 550 mm |
| Uprights | Custom RAIL-001, 2 mm steel, 25 mm asymmetric face, 35 mm return; 9.5 mm true square holes |
| Rack interface | 465.1 mm hole-center separation, 451 mm clear opening, 44.45 mm U pitch; offsets 6.35 / 22.225 / 38.1 mm within each U |
| Rail location | Independently adjustable centerline setbacks 100–200 mm from front/rear body faces; default 130 / 100 |
| Rail bridges | 3 mm formed-bracket envelopes with separate rail/tie fixings; 82 mm end bridges, 46 mm intermediate bridges; holes/welds/torques not drawing-released |
| Outer skins | 1.5 mm formed aluminum; 5052-H32 candidate, finish/formability coupon required |
| Base | 8 mm steel bridge + gussets + threaded M16 boss; load-bearing parts isolated from decorative stainless trim |

Welded tube-frame construction is the first-prototype route, not a frozen production process. Specify steel grade and certified properties, tube corner radii, end caps/drainage, weld sequence, weld sizes and acceptance criteria with the fabricator. Current CAD uses ideal sharp-corner hollow-stock sections. Do not laser-cut or weld directly from its envelopes.

Top/bottom beam inner faces are 2 mm beyond the nominal U field. No brackets or hardware may intrude inside the 451 mm opening or the 482.6 mm equipment-faceplate envelope. Upright face width is added only outboard of each hole center; centering a 25 mm face would incorrectly narrow the opening. The bracket model shows the intended load transfer but is not a checked sheet-metal pattern or joint-capacity calculation.

Load path: equipment's qualified rail kit → custom upright → bolted bridge → welded depth ties/end frame → gusseted base bridge → threaded boss/stud → leveling foot → verified floor. Cosmetic panels, perimeter tubes and emblems carry no equipment load.

## Lead geometry and equipment fit

The 24U body is 600 × 1000 × 1180 mm; closed overall envelope on nominal feet remains approximately 680 × 1080 × 1225 mm. The 680 mm disc footprint is wider than a 600 mm rack-row pitch. Allow additional door swing, side-removal, rail extraction and handling space; do not use the closed envelope as a service-clearance specification.

Default upright centers are Z +370 / −400 mm (770 mm centerline span); the 2 mm steel outer mounting faces are +371 / −401 mm. In the explorer, the conservative depth screen leaves 80 mm rear connector reserve plus a 20 mm rear-door allowance, resulting in a 770 mm chassis-depth budget. This is a screen, not proof of rail-kit length, rear-face connector direction or cable bend compliance. The 1000 mm body will not accommodate every dense enterprise chassis; the 1200 mm option preserves the same design.

The conservative front space estimate is 75 mm after a 40 mm projection allowance (the illustrative handles reach 36.15 mm ahead of the rail centerline) and a 15 mm front-insert allowance. Actual DAC/fiber/power connectors, handles, rails and cable arms must be evaluated for selected equipment. [Dell's XE9680 integration guidance](https://infohub.delltechnologies.com/en-sg/p/poweredge-xe9680-rack-integration/) is a useful example of a device with a specific 93.12 mm adapter-to-door cable requirement; it is not a universal rack rule. Increase the front setback for such requirements and recheck chassis depth rather than claiming the default fits everything.

Required fit matrix before hardware freeze: actual representative switch/gateway, NAS/server, GPU server, rail kit part number, chassis depth, sliding-rail adjustment range, flange type, maximum installed mass, front/rear projection, cable/CMA bend envelope, door swing/extraction and service operation. The site's devices remain illustrative; their geometry is not vendor CAD.

## Hardware candidates and hold points

Catalog/source prices and budget allowances are itemized in `bom.js` and the engineering page's downloadable CSV. No order has been placed and no supplier quotation has been obtained.

1. **Rails / cage nuts.** [Penn Elcom R0863/2MM-24](https://www.penn-elcom.com/us/24u-rack-rail-with-full-holes-0-08in-thick-r0863-2mm-24) is a 2 mm / 1070 mm catalog benchmark ($19.89 displayed). Its cross-section CAD was not obtained, so the model and costed custom rail are **RAIL-001**, not a claimed Penn part. Check [S1172](https://www.penn-elcom.com/m6-cage-nut-for-2mm-thick-rack-rails-s1172) grip and hole-edge/bend clearance on physical finished coupons. Acquire the controlled rack interface standard before a tolerance release.
2. **Panel latch.** [Southco E2-50-101-10](https://media.southco.com/media/static/Literature/e2-sp.en.pdf) is a near-edge hidden lift-off latch/keeper candidate. The reserved 62 × 52.4 × 38 mm envelope is deliberately visible inside. The concealed actuator configuration is tool-operated; a flush finger cap is custom and needs travel/force checks. Keep lower hooks load-bearing, provide secondary retention/handling and check the entire removal sequence. The braid is not a safety tether. A single latch's catalog data does not establish large-panel flatness or retention.
3. **Door hinge / latch.** [Southco F6-1-1 drawing](https://media.southco.com/media/static/JDrawing/J-F6-1.pdf), three hinge candidates per front door, 126 mm envelope. The viewer fixes the nominal pivot axis and adds fixed/moving hardware envelopes but **does not reproduce the proprietary F6 linkage or establish its swing clearance**. [E3-56-15](https://southco.com/en_any_int/e3-56-15) compression latch uses a 3.2–6.4 mm grip: strike, gasket compression, cassette and fasteners must be stacked from the exact drawing. No unsupported hinge/load assumption or arbitrary pull-up dimension is frozen.
4. **Feet.** [JW Winco GN343.1-60-M16-KR](https://live-catalog.jwwinco.com/pdf/winco/us/343_1.pdf?dispositiontype=attachment) female-socket foot + separately specified M16×45 dog-point stud is the compact candidate. Preliminary overall height is 37.5 + 45 − 16 = 66.5 mm; nominal floor clearance is 45 mm, leaving 21.5 mm inside the lower body. The 16 mm value is a catalog available-thread-depth reference, **not a verified engagement or adjustment specification**. Manufacturer bottoming instructions, tolerance, lock access and actual cover/ball-socket section still need verification. The long 80 mm-stud GN343.2 was rejected for packaging. The rubber-foot 7 kN purely axial component figure is not a cabinet rating. Upper cosmetic socket is now 32 mm diameter to avoid the earlier 30 mm boss / 29 mm cover mismatch. Full cover/foot packaging remains open; decorative foot shapes are not detailed bought-part CAD.
5. **Bonding.** nVent ERIFLEX MBJ10-300-6 / 556610 is the candidate 10 mm² × 300 mm braid; use dedicated masked terminals for doors, side panels and subassemblies as the responsible electrical engineer specifies. Current drawn routes are envelopes and deliberately are not modeled as proof of continuous connection during full panel separation. Bonding disconnect/reconnect and continuity inspection are mandatory service steps; evaluate actual fault current and applicable standards.

## Thermal and cable-management development

The lead is mesh-front/mesh-rear; glass is not accepted as an equivalent thermal design. Proposed perforated stock: 1.2 mm aluminum, 3.5 mm round holes on 4.2 mm triangular pitch, approximately 63% geometric free area in the perforated field before margins, borders, backing, gaskets or obstructions. This is a procurement target only. The explorer still renders holes through a texture, not a manufactured perforation field or CFD model.

There is no agreed heat-load rating. For scale only, 10 kW / (1.2 kg/m³ × 1005 J/kg·K × 10 K) is approximately 0.83 m³/s of ideal air flow; this ignores pressure loss, mixing and equipment fan curves and is not a cooling specification. Build/test representative doors-closed configurations after defining equipment and ambient conditions. Preserve front/rear airflow separation with blanking and side seals; don't obstruct exhaust with PDUs or cables.

Cable-entry cutouts, protected edges, removable connector-sized plates, PDU mounting and strain relief remain unreleased. Existing rear slots in the viewer are illustrative. Heyco DS-125 edge channel is a candidate, not proof of entry sizing. Determine actual power-feed, bonding and installation requirements before electrical integration. The home-closet scene is not evidence of adequate room ventilation or safe floor loading.

## Nominal mass and cost

Scoped 24U STEP mass at assumed densities: chassis tube 43.345 kg, four rails 3.478 kg, six shell pieces 13.803 kg; **60.626 kg total scoped mass**, each bare side 4.675 kg. Missing brackets, feet, door/rear mesh, trim, stiffeners, fasteners, adhesives, bonding and finish are not included. Use **100 kg cabinet mass only as a conservative preliminary calculation allowance**, not a reported cabinet weight. Replace it with a complete part mass roll-up before structural review or shipping estimates.

One-off direct-build allowance is approximately **$5,516–$10,191 USD**, or **$6,895–$12,739 with 25% contingency**. Range endpoints sum the same BOM quantities at their low/high unit assumptions. Estimated labor is 12 hours chassis work plus 8 hours final assembly at $80–$140/h. These are modeling assumptions, not contracted labor rates. Catalog price conflicts and source quality are recorded row by row. Engineering, analysis, tooling/fixture capital, testing, certifications, equipment/PDU, freight and tax are excluded. No production-volume cost is claimed.

## Analytical screening — not a load qualification

Using g = 9.80665 m/s² and idealized sharp-corner 40 × 40 × 3 mm RHS area 444 mm²:

| Separate idealized case | Calculation | Result |
|---|---|---|
| Equipment-only load | 500 × g | 4903 N |
| Equal four-post compression | (500 × g / 4) / 444 | 2.76 MPa nominal average stress |
| Gross load with 100 kg cabinet allowance | 600 × g | 5884 N |
| Equal three-foot contact, illustrative only | 600 × g / 3 | 1961 N per foot |
| Eccentric foot bridge, that reaction only | 1961 × √(27²+46²) / 1000 | 104.6 N·m resultant moment |

Equal three-foot contact is **not** a worst-case reaction model. Local rail-hole loading, asymmetric payload, beam/tie deflection, frame racking, welds, bracket slip/tear-out, thread-root strength, boss pullout, floor contact and tip stability may govern instead of post axial stress. Do not convert these numbers into a safety factor or a product rating. Engineer loaded/empty, extracted-device, door-open, one-side-off, uneven-floor, installation and transport cases. No FEA was performed in P1.

## Manufacturing and qualification gates

**Gate A — controlled hardware and material review (next).** Mechanical engineer and fabricator approve load/CG and equipment-fit requirements, steel grade, welds, stock/bend radii, rail/foot/latch/hinge CAD, drawing tolerances and interfaces. Obtain finish coupons before full cosmetic parts. Aluminum 5052 is a formability candidate, not a promise of matched decorative anodize; [Alro's material description](https://www.alro.com/divsteel/metals_gridpt.aspx?gp=0146) supports the forming route, while full-size cosmetic acceptance still needs samples. Separate unlike-metal contacts where appropriate without breaking the intended bonding path.

**Gate B — manufacturing drawings and engineering mule.** Release controlled part and assembly drawings, dimensioned holes/slots, bend allowances, datum system, fastener grades/torques, bonding mask map and assembly sequence. Nominal crown seam is 1.2 mm; do not release it without a bend/flatness/coating tolerance stack. Prototype frame and rail joints first; measure squareness/parallelism before committing to polished cosmetic parts. Complete a hands-on side-release and door/rail extraction test.

**Gate C — qualification plan.** Agree static/load-distribution, stability/extraction, support adjustment, service-cycle, bonding, thermal, environmental and transport tests and acceptance criteria with a qualified engineer/lab. Candidate scopes include [IEC60297-3-100](https://webstore.iec.ch/en/publication/1283), [IEC61587-1](https://webstore.iec.ch/en/publication/65981) and [UL2416](https://www.shopulstandards.com/ProductDetail.aspx?productId=UL2416); applicability depends on product, market and use. Publisher summaries are not substitutes for controlled standards. Do not improvise unattended 500 kg testing or use unqualified assemblies around people.

**Gate D — family variants.** Preserve design language and common parts, but separately sign off 48U stiffness/stability and panel handling, supported equipment depths, glass cooling, caster loads/brakes, suspended wall attachment and 48U floor-bearing wall restraint. Intended sales markets and installation substrates are still unspecified.

## What P1 verification does and does not prove

- Automated checks cover nominal rack dimensions/holes, finite geometry, shared section rules, rail setting bounds, nominal support registration, selected service-clearance envelopes, correct AR invalidation and existing viewer regressions.
- Scoped CAD checks cover positive/valid closed solids, true rail-hole volume removal, named parts, millimeter units and STEP count/volume round-trip. Source hashes bind the export to the parameter snapshot.
- No physical prototype, supplier-approved hardware fit, full-assembly interference certification, signed structural design, FEA, cooling test, production quote or compliance evaluation exists yet. Any unresolved finding remains a release hold, not a concealed assumption.