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  • Originally titledThe Box Beam Sourcebook by Jorgensen

Gridbeam for Vehicles

Grid beam is a simple modular construction technique. The core technology of this system is the beam, which has holes in it along its entire length, on all 4 sides. As well as holes, it is also able to create tri-joints, which are connections between 3 beams in which each beam is secured with 2 bolts. Gridbeams (in wood, galvanised steel and aluminium) are available for purchase from stores, and can be made yourself using standard industry components (lumber or metal pipes cut to the sizes described on this page). Wall thickness of the steel gridbeams is 14, 13 or 12 gauge (0,21 mm - 0,24 mm - 0,27 mm). Wall thickness of the aluminium gridbeams is 11 gauge (0,3 mm). The gridbeam system also uses hardware (hex nuts and bolts, flat washers, carriage bolts, joint connector bolts and weld nuts, external tooth lock washers and flange/flex-type locknuts, castle nuts, thread-locking fluid), panels (in same sizes as the gridbeams, in plywood, signboard, hardboard, sheet metal, fibreglass, plexiglass, ABS plastic, lexan, or safety glass), accessories (bicycle wheels, garden tractor wheels, garden cart wheels, (pillow block) wheel bearings, (pillow block) (axle) rings, angle plates/brackets, trailer torsion axles and wheels, live split axles and transaxles, sprockets, pulleys, ... ) and adapters (custom-made metal components that make non-compatible accessories fit unto gridbeam).

Hex nuts and bolts are used with most metal gridbeams as they are the strongest. Lockwashers, locknuts and thread-locking fluid is used for vehicle projects. Castle nuts are used to fasten axles. Joint connector bolts and weldnuts and carriage bolts are useful for when panelling needs to be attached to gridbeams because they are much flatter than regular hex bolts and nuts.

All hardware should be stainless steel, grade 1 hardness or more, with nuts having equal hardness level as the bolts, bolt lengths being equal to the beam thickness x2 (for allowing them to go through 2 beams).

Plexiglass and lexan are used for view ports and windows, and for windshields safety glass is used. Fibreglass and plexiglass are used for vehicle body panels. Sheet metal is used for decks in vehicles, ...

Most gridbeam vehicles don't have a clutch; vehicles are stopped instead and the gear is changed. Sometimes, there are no gears but a 12V/24V selector is present, allowing to speed up the vehicle when needed. Most also don't have a regular differential; instead live split axles or transaxles are used. Suspension is also present, often in the form of trailer torsion axles or suspension forks.

When making adapters yourself, use steel plates with a thickness between 1/8 inch and 1/4 inch (0,32 mm - 0,63 mm ). Use a drill in a drill press vise for accurate drilling.


Grid beam is a system of beams in which the width of each beam is equal to the hole spacing. The holes are always placed in the middle of the beam width, and the hole spacing refers to the space between the holes in the other direction. In the imperial system, beam width can be 1 inch, 1,5 inch and 2 inch. Hole spacing is similar (1 inch, 1,5 inch and 2 inch). In the metric system, beam width can be set to 25 mm (which is almost identical to 1 inch as 1 inch = 25,4 mm), 40 mm (almost identical to 1,5 inch as this is 38 mm), and 50 mm (almost identical as 2 inch is 50,8 mm). Hole spacing follows accordingly. Lengths of the beams need to be multiples of the beam width. In the imperial version, the lengths are per foot and per half foot, in the metric system it can be done per meter, per 1/2 meter and per 1/5 meter). The hole diameter needs to be about 25-35% of the beam width, and the bolts need to be 1 mm smaller than the holes for metal gridbeams and 2 mm smaller than the hole for wooden gridbeams. In the imperial version, popular hole sizes are 11/32 inch, and 7/16 inch and popular bolt sizes are 5/16 inch and 3/8 inch. For the metric gridbeam, we can use a 6 mm bolt and 7-8 mm holes for the 25 mm gridbeam; a 9 mm bolt and 10-11 mm holes for the 40 mm gridbeam and 12 mm bolt and 13-14 mm holes for the 50 mm gridbeam. Use the 8,11 and 14 mm holes for wooden gridbeams, and the 7, 10 and 13 mm holes for metal gridbeams. Bolt sizes (6, 9 and 12 mm) are the same for both wooden and metal metric gridbeams. Reasons for this are that we can then reduce the number of different bolts sizes, and still use the smallest bolt with the largest hole (important for projects that use multiple gridbeam sizes). When buying imperial gridbeams and cutting them to metric sizes, also increase the hole size to metric where needed, and when the imperial beams have larger holes than in the metric version, simply keep the hole size but use metric bolts in them.



A wide range of furniture (such as desks, beds, tables, chairs, lcd monitor stands, ...) have been designed.


Several electric vehicles have been designed with gridbeam. Examples are the Electric Vehicle Test Bed, Solar Powered Utility Vehicle, Scamp, Electric Tote Goat, Japanese Bear, X-wing, Vanda, Panther Electric, Willits High School Electrathon Racer, Star Lite, Soltrain, Rail Rocket,...

PV mounts

A simple PV panel stand (for 65" x 39" and 75" x 39" PV panels) that can rotate along the horizontal plane (single-axis) can be made using gridbeam.

When using imperial gridbeam, it can be made 24 inch (=2 foot) high, 42 inch (=3,5 foot) long and 78 inch (=6,5 foot) wide. The panel can then be rotated by a stepper motor by putting it on a plywood supported by an axle. The axle needs to be at least 78 inch long (75" for the panel + 1,5" + 1,5" for the beams + space to mount the electric motor). By making it this way, the whole has a limited height, which reduces the possibility of damage by wind.

When using metric gridbeam, make it 50 cm high, 1m long and 2m wide, with a axle that is at least 2m wide.

OSE designs


grid-beam-like components before they are assembled into a LifeTrac
LifeTrac 5 under construction
main article: LifeTrac

The basic frame of the LifeTrac is bolted together from 4x4x1/4" square tubing, in an arrangement very similar to the "grid beam" techniques.

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