Current direction / 29 October 2026
Two donor families.
Three body designs.
Our primary design is a roughly 26,000 lb medium-duty compact targeting 20 × 8 × 8 ft when stowed, with clearance margin. F-650 and equivalent donors remain candidates. The larger family is a Class 8 under 30 ft.
A / Primary · expanding compactLow when stowed.
Room to rise.
A fixed lower tub, telescoping roof and overlapping rigid sliding panels. Raise slowly while stationary; lock at usable heights. Retract and mechanically latch before travel or dimension-limited parking.
- Primary stowed target
- <20 × <8 × <8 ft
- Donor loaded rating target
- ≈26,000 lb
Length × width × height. Exact donor fit is unresolved: the cab, chassis and fittings must fit too. The primary must fit below 20 ft; under 22 ft remains only for the fixed tall alternate. A 7 ft height is not required.
See the roof states →
B / Alternate · fixed compactStanding room.
Always ready.
The same short-wheelbase medium-duty family, with a fixed tall shell and no lifting roof. Keep the finished truck under 22 ft and accept oversized parking treatment.
- Loaded rating target
- ≈26,000 lb
- Carrier-height study
- ≤12 ft
Simpler shell joints and permanent headroom. Park on suitable permitted sites; a tall body does not have unrestricted parking rights.
Compact towing limits →
C / Larger donor · Class 8Use the full
road envelope.
Already oversized for city parking: retain width and height for living space, with the powered truck/RV strictly under 30 ft. Keep its fifth-wheel and trailer-clearance needs in the layout.
- Body width ceiling study
- 102 in
- Overall height ceiling study
- 14 ft
California ordinary-road ceilings, subject to route restrictions and clearance margin. Approximately 80,000 lb is the entire loaded combination; the trailer adds length.
Heavy layout and loads →
A / How the primary body changes
One footprint.
A changing roofline.
Illustrative roof lift: 24–36 in above a 95 in stowed exterior height. Fixed width; no side slide-outs assumed. This is a mechanism study, with donor fit and standing headroom still to resolve.
Ford’s 2022 brochure lists 90.2–94.4 in regular-cab height and 95.5 in front-fender width: a possible starting envelope, with very little width margin before mirrors. Cabovers may save length but are not assumed lower. A 7 ft city height limit is tighter than this cab; lowering suspension is an unverified separate study. Preserve driving visibility, restraints, structural load paths and escape routes.
- 01 / Stowed and latchedUpper shell nests over the lower tub. Roof fittings fit inside the measured parking envelope; positive locks carry road loads.
- 02 / Slow, stationary expansionGuides keep the lift square. Obstruction detection, load holding and emergency stop protect the moving panels. No pressure operation during movement.
- 03 / Raised and supportedMechanical supports hold the roof. Qualified locked positions close weather, pressure and RF joints. Intermediate heights stay unpressurized unless separately engineered.
What counts as oversized? Santa Monica and other cities
Santa Monica Municipal Code §3.12.860 and the city’s current guidance say vehicles exceeding 20 ft long OR 8 ft wide OR 8 ft tall need an overnight oversize permit from 9 pm to 6 am. We target below those dimensions with margin. Commercial registration is ineligible for that permit.
Los Angeles’s Controller summarizes a different rule: over 22 ft long or 7 ft high in signed zones, 2–6 am. San Diego separately restricts RVs. There is no verified “most cities” envelope. Retraction addresses dimensions only; posted parking, RV use, occupancy and trailer restrictions still apply. Raising the roof changes the parked envelope.
Santa Monica municipal code · City permit guidance · Los Angeles Controller · San Diego city guidance · Ford donor dimensions
Checked 29 October 2026. Verified against the municipal code and city guidance. Fixtures and accessories count, except single-post radio antennas; trailers of any size are covered overnight.
Custom body, donor chassis or our own frame?
The registration baseline retains an identifiable titled donor chassis with a custom body and subframe. We will also study an owner-designed main frame for packaging freedom. A new frame does not automatically inherit the donor’s VIN, 26,000 lb rating or towing capacity.
California provides altered-vehicle and specially constructed vehicle routes. A new main frame needs its own DMV/CHP identity review, emissions determination and engineering/rating plan. The limited SB100 emissions certificates are not a blanket limit on every homebuilt registration. No custom-frame approval is established.
California DMV: altered and specially constructed vehicles
Another option: a customer-completed rolling kit
Supply a substantially assembled chassis and body, with the customer completing assembly and installing a specified compliant engine, ECU and matched emissions system. Study this alongside an OEM-chassis build; neither requires assuming an SB100 allocation.
A kit with a customer-installed powertrain has commercial precedent. Our exact 26k motorhome package still needs its manufacturer and registration roles defined. A missing battery or token final step is not an established exemption, and an engine certificate alone does not settle every vehicle-level requirement.
Custom 8×8: maximum weight at 20 ft or 30 ft?
With four axles and just 3 ft total front/rear overhang, the California general weight table permits 53,500 lb at 20 ft OAL (17 ft outer-axle span) or 60,000 lb at 30 ft OAL (27 ft span). These are illustrative custom layouts, not established chassis ratings.
Optimistic table bounds are 55,500 lb at a rounded 20 ft axle span and 62,000 lb at 30 ft span, but those leave no demonstrated allowance for tire/body overhang within the same OAL. Through 30 ft axle span, adding a fifth or sixth axle does not raise the table’s whole-group ceiling.
All figures are total loaded weight, not payload. Every consecutive axle group, tire/equipment rating and local/bridge restriction still applies. Eight-wheel drive itself grants no extra allowance. The primary compact target remains approximately 26,000 lb GVWR.
Caltrans axle-spacing weight table
Running gear: solid axles or independent geared wheel ends?
Compare a conventional solid driven axle with independent wheel suspension: a chassis-mounted differential drives each wheel through an articulated half-shaft. Optional reduction gears at the hub reduce upstream drive torque; a portal offset adds ground clearance but may compete with our low-height target. This military-style layout is an alternate study, not selected hardware.
At an illustrative 60,000 lb over eight wheels, static load is 7,500 lb per wheel. Suspension, wheel ends, shafts, steering and brakes need a coordinated design; no military donor part is assumed suitable merely by appearance.
Electroforming is a candidate for separate housings and covers, not a demonstrated process for an entire functioning axle. Pure nickel and ordinary iron/nickel alloys are magnetic. High-phosphorus nickel can be essentially nonmagnetic as deposited, but typical electroless coatings have low ductility and do not establish a road-rated structural alloy. Housing mass depends on stiffness and fatigue allowance; no complete-system weight saving is claimed.
Electroformed axle: how close can the weight get?
Our geometry-based solid-axle study uses 7,500 lb static per wheel, combined impact/braking assumptions and matched steel references. In the target iron-rich material scenario, a 160 mm tube needs 9.1 mm finished wall versus 8 mm steel. The modeled housing plus straight-shaft substitution adds about 28 lb to a 750 lb subtotal—roughly 4%.
Using a 180 mm tube gives roughly 2% extra in the target case; lower conservative allowables give about 9–14% across the two diameters. These totals include an assumed 441 lb common-parts allowance, not a weighed commercial axle, and exclude tires, suspension and steering additions. Retaining purchased steel shafts reduces the modeled penalty.
The independent geared-hub study separately estimates 344 lb for steel cases plus straight half-shafts, 354 lb in the target scenario and 387 lb in the conservative scenario. That excludes the rest of the suspension and drivetrain and is not comparable to a complete axle.
All material allowables are hypothetical inputs. The designs need thick-deposit fatigue/ductility evidence and detailed bearing, joint and gear alignment work. Iron-rich materials are not assumed nonmagnetic; no road-rated axle or complete-system weight is established.
A + A / B + B / C + C
Build a pair. Tow its twin.
Every variant aims to tow a matching second vehicle for more living and carrying space, or pull a compatible ordinary trailer. Each vehicle remains independently usable. Reserve frame-rated coupling, brakes and transport interfaces in both copies.
Compact: two fully loaded 26,000 lb trucks already total 52,000 lb before a carrier—above the diesel F-650 family’s 50,000 lb combination example. Reduced transport weights are necessary for that example.
Heavy: two assumed 26,000 lb vehicles plus an assumed 12,000 lb carrier total 64,000 lb, before extra cargo. A tall Class 8 on a carrier may exceed 14 ft; wheel-on-road towing needs its own engineered driveline, steering, braking and coupling solution.
Matching-pair towing is a design goal for all three, with no verified complete donor pair or tow system. Towing adds no rating: the first vehicle’s combination, axle, hitch, route and length limits still govern. Neither an 80,000 lb payload nor two 80,000 lb trucks is implied.
