01 — Overview
All-Plastic Caster with Filament Torus Bearing Technology
The EFC Caster System is a fully 3D-printed — or injection-moulded — caster wheel assembly using no metallic hardware, no pressed-in bearing inserts, and no lubrication of any kind. The entire bearing function is performed by standard 1.75 mm nylon filament wound in-situ into toroidal grooves machined into the printed race geometry.
Available in fixed and swivel variants, the system is built on the Evolutiv Filament Construction (EFC) platform — a set of six patented-pending mechanical primitives that use standard FDM printer feedstock as the sole functional mechanical element beyond the printed geometry itself.
The parametric design scales to any reasonable load requirement by changing wheel diameter, width, or the number of toroidal filament rows — all from the same spool of filament, on the same printer, from the same parametric model.
FIG. 1 — Exploded assembly view. All filament entry slots visible. Five components total.
02 — Prototype Documentation
Reduction to Practice — March 2026
FRONT — SWIVEL VARIANT
SIDE — SWIVEL MECHANISM
END PLATE — MOUNTING HOLES
WHEEL — OCTAGONAL RACE
FIXED FORK — SIDE VIEW
FIXED — FRONT VIEW
BOTH VARIANTS COMPARED
All photographs: Pristina, Kosovo, March 2026. Device metadata timestamps available. Click any image to enlarge.
03 — Assembly Components
Five Printed Parts — Zero Hardware
COMPONENT 01
Mounting Plate
Square base plate with four corner mounting holes. Accepts filament pin fasteners or standard M3–M5 screws depending on application. The swivel variant integrates the lower swivel race into this plate.
COMPONENT 02
Fork / Yoke Assembly
The structurally most complex part. Contains the upper swivel bearing housing (swivel variant) with tangential filament entry ports for two radial and two axial torus rings. Fork arms descend to cradle the wheel and accept the axle pin.
COMPONENT 03
Wheel
50 mm diameter × 25 mm width. Crowned tread profile for load distribution. Three internal toroidal slots accept the bearing filament rows. Standard configuration: 3 rows. Maximum configuration: 5 rows for heavy loads.
COMPONENT 04
Outer Bearing Race
Octagonal outer profile (polygonal intermediate race — EFC Primitive P2). Under radial load, polygon flats create defined linear contact zones with the filament torus, progressively increasing contact area with load. Self-compensating geometry.
COMPONENT 05 — BEARING ELEMENT
1.75 mm Nylon Filament Torus Rings
Standard FDM printer feedstock inserted through tangential entry ports after assembly. Each torus is a continuous loop of filament filling a circular channel. Entry ports are sealed with a printed press-fit plug. The filament is the bearing — no balls, no races, no grease. Manufactured to ±0.02 mm diameter tolerance as standard commercial product — tighter than typical FDM feature resolution.
04 — Technical Specifications
Performance & Dimensional Data
| Parameter | Value / Description |
|---|---|
| Wheel diameter | 50 mm (standard) — parametric, any size |
| Wheel width | 25 mm (standard) — parametric |
| Bearing element | 1.75 mm nylon filament, ±0.02 mm diameter tolerance |
| Bearing rows (standard) | 3 toroidal rows |
| Bearing rows (maximum) | 5 toroidal rows |
| Load rating — sustained | 25 kg per caster (target, heavy load testing in progress) |
| Load rating — 4 caster assembly | 100 kg total |
| Metal components | Zero |
| Lubrication | None required |
| Swivel bearing configuration | 2 radial + 2 axial filament torus rings (EFC Primitive P7) |
| Variants available | Fixed fork; swivel (360°) |
| Mounting | 4-hole square plate — filament pins or standard screws |
| Manufacturing methods | FDM 3D printing; injection moulding |
| Standard print material | PLA, PETG, ABS, nylon (housing); nylon (bearing element) |
| Food / pharma grade option | PP or food-grade PETG housing + nylon bearing |
| Chemical resistant option | PEEK or POM housing |
All specifications refer to the 50 mm standard caster. Parametric scaling available for custom sizes. Contact shop.evolutiv.ai for custom specifications.
05 — Applications
Where This Technology Is Used
Luggage & Bag Repair
Parametric replacement wheels for any luggage brand. Measurable from worn part. Printed locally by repair shops or individuals. No import required.
Food Production
Zero contamination risk — no grease, no metal ions. Washdown resistant. Food-grade material options. Simple one-line compliance statement.
Pharma & Chemical
PEEK or POM housing for aggressive chemical environments. No lubricant degradation under solvent exposure. Autoclavable material options.
Hobby CNC & 3D Printers
Replacement for V-slot wheels. No pressed bearing insert, no 5 mm shaft required. 10 mm+ bore with 16× the bending stiffness of conventional designs.
Industrial Equipment
Non-standard guide and track wheel replacement. Conveyor idlers, sliding gates, discontinued OEM parts. Printable from parametric model same day.
General Industrial Carts
Standard 25 kg × 4 = 100 kg cart capacity. Scales to any load by increasing rows or diameter. No lubrication maintenance schedule.
06 — Variants
Fixed & Swivel Configurations
Fixed Fork
EFC-CAST-F
- Single-direction rolling only
- Higher axial load capacity — no swivel joint in load path
- Lower total height — more compact assembly
- Simpler geometry — fewer parts, faster print
- Ideal for guided carts, conveyor systems, linear equipment
- Wheel bearing: 3 radial torus rows (standard)
Swivel (360°)
EFC-CAST-S
- Full 360° yoke rotation about vertical axis
- Swivel joint: 2 radial + 2 axial filament torus rings (EFC P7)
- Smooth swivel under load — no stick-slip
- Wheel bearing: 3 radial torus rows (standard)
- Ideal for trolleys, carts, equipment requiring free manoeuvre
- Swivel lock variant available (printed detent)
07 — Intellectual Property
Design Disclosure & Licensing
Protected Technology — Prior Art Established
The EFC Caster System is built on the Evolutiv Filament Construction System, a set of mechanical primitives covered by formal design disclosure documents establishing the date of conception and technical specificity of each invention. The tangential-entry filament torus bearing (P1), polygonal intermediate race bearing (P2), and multi-axis combined radial/axial bearing (P7) are the core protected elements. Demonstration files are available under CC BY-SA 4.0. Parametric source files and commercial licences — including injection-moulding rights — are available through shop.evolutiv.ai.
EFC-DISCLOSURE-2025-001 / EFC-DISCLOSURE-2025-002 — Originator: Mark Culaj, Evolutiv AI SH.A, Pristina, Kosovo