Horizontal Trolley Design for Paint Line
Defence-grade components require robust material handling to maintain strict surface coating parameters. In coordination with leading government and defence contractor EPTEC, KEVOS® developed a complete mechanical layout and optimization proposal for a heavy-duty, space-saving horizontal trolley system. Integrating a high-rigidity rectangular hollow section (RHS) beam matrix with advanced mobility hardware, the system eliminates shop-floor storage bottlenecks while optimizing coating throughput.
Executive Summary
project profile & parametersManufacturing and coating dynamic defense-grade components presents unique geometric and material handling obstacles. Heavy, irregularly shaped sub-assemblies demand a highly durable platform that resists structural flexing under loading limits while maintaining maximum agility inside tight paint-line cleanrooms. This mechanical engineering portfolio highlights KEVOS®’ design proposal for EPTEC's specialized paint facility. By substituting legacy stationary frameworks with a highly modular, RHS-reinforced steel and aluminum mobile chassis, the proposed design solves workspace floor constraints, reduces manual handling risks, and establishes an active, repeatable path for industrial surface applications.
Eliminate bulky structural supports. Leverage optimized geometric trussing and heavy-duty casters to provide stable, deflection-free transport within a minimized physical footprint.
- Construct robust structural boundaries using high-stiffness RHS beam frameworks.
- Incorporate high-load-rated swivel and fixed casters to guarantee predictable travel paths.
- Enable modular utility via collapsible/stackable frame layouts and adjustable supports.
Visual Knowledge Map
structural framework to paint-line integrationModeling RHS longitudinal beams, corner cross-braces, and high-load casters in a unified virtual CAD environment.
Core Concepts
mechanical design definitionsRHS Beam Matrix
Rectangular Hollow Section (RHS) steel or aluminum frames welded in a grid pattern to secure extreme structural stiffness with minimized weight.
Load Rating
The maximum weight limit a single wheel or beam can support without experiencing structural deformation or mechanical failure.
Torsional Twist
The warping forces experienced by a cart moving over uneven workshop surfaces, solved with diagonal corner bracing.
Industrial Mil-Spec Finish
Using a resilient coating (military-spec green) to protect the metal frame from chemical cleaners and abrasive overspray.
Process Line Repeatability
Ensuring the trolley locks reliably in place, allowing automated spray guns to apply coatings evenly across batches.
- Prevents part reject rates
- Optimizes spray coverage
360-Degree Rotation
An optional, integrated rotating top deck that gives operators full access to all part faces from one standing position.
Footprint Optimization
Designing frames that fold down or stack together to save valuable workshop floor space when not in use.
Fixed Caster Tracking
Using fixed casters to ensure predictable, straight-line travel paths during high-volume production cycles.
Frameworks & Models
structural & mobility validation modelsThe Structural Force Distribution
Structuring 85% of design resources into the welded RHS beam matrix ensures robust strength, while 15% is spent selecting and aligning high-load casters to prevent flat-spotting.
Coating Process Risks
Over-Spray Build
Controlled via open-grid platform design
Caster Jamming
Prevented using sealed precision bearings
Structural Flex
Damped via continuous weld fillets
Workplace Clashes
Avoided with collapsible frame hinges
Material Handling Economics
| Evaluation Metric | Legacy Fixed Station Framework | Proposed KEVOS® Mobile Trolley |
|---|---|---|
| Workflow Agility | Poor (Demands crane lifts for part rotations) | Excellent (Seamless, manual low-friction rolling) |
| Storage footprint | Constant (Consumes valuable floor space) | Minimal (Offers folding or stacking frame options) |
| Process Cleanability | Low (Massive surfaces accumulate paint) | High (Open longitudinal frame cuts overspray) |
| Coating Repeatability | Difficult (Requires manual part flips) | Precise (Optional 360-degree rotating top deck) |
Integrated Mechanical Design Loop
System Variables: load dimensions · beam stiffness · caster wear · cleanroom clearances.
Process Flow
consecutive mechanical design phasesWorkflow Map
Verify workshop footprints and chemical exposure limits.
Chassis Design
Size the steel RHS longitudinal and transverse support frames.
Bracing Layout
Add diagonal gussets in SolidWorks to stop frame twist.
Caster Select
Select high-load casters with sealed chemical-resistant bearings.
Feature Add
Integrate optional 360-degree rotating platforms or tool hooks.
Clash Audit
Run SolidWorks simulations to verify deflection limits under load.
Drafting Pack
Compile fabrication blueprints and weld symbol notes.
Project Hold
Secure design files, ready for future EPTEC line rollouts.
Relationship Diagram
system feedback loopDependencies & Interactions
mechanical design boundariesTrolley stiffness depends on diagonal corner bracing — reinforcing joints with gussets stops frame warping under heavy, lopsided loads.
Handling safety depends on caster weight ratings — choosing high-load, sealed-bearing wheels prevents flat-spotting and rolling resistance.
Corrosion lifespan depends on mil-spec green finish — high-barrier industrial coatings protect frames from paint-stripping solvents.
Cleanroom usability depends on collapsible hinges — designing folding joints lets crews store the trolley in small gaps.
Spray consistency depends on open platform geometry — using parallel hollow beams reduces overspray paint buildup on the trolley.
Operator comfort depends on handle heights — setting push bars at standard waist levels prevents muscle strain on long shifts.
Key Takeaways
critical project insights- Stiffness is geometric — welding steel RHS profiles in a grid pattern stops structural flex without adding excess frame mass.
- Sealed bearings stop jams — choosing closed caster bearings prevents paint dust and overspray from seizing wheels.
- Design open frames for paint lines — using parallel hollow beams cuts down on-trolley paint buildup and cleaning needs.
- Keep storage frames collapsible — including folding hinges allows workshops to reclaim valuable floor space when not in use.
- Integrate 360-degree rotations — an optional rotating deck helps operators coat all part faces without shifting positions.
- Protect metal with mil-spec finishes — robust industrial coatings shield chassis from chemical wash solvents.
- Add floor anchoring when needed — optional bolt plates secure the trolley when applying highly consistent coatings.
- Maintain complete parametric designs — verified CAD files remain ready to build when factory budgets resume.
Revision Sheet
high-impact review- The Task: Design a rigid, space-saving horizontal trolley system for EPTEC's defence-grade paint facility.
- The Method: Model a robust steel RHS frame with high-load casters and collapsible space-saving joints in SolidWorks.
- The Value: Fast washdowns, zero water pooling, and quick on-site assembly times.
- Chassis Dimensions: Welded steel/aluminum RHS beams (approx. 1.5m L x 0.6m W x 0.8m H) with diagonal joint gussets.
- Mobility Configuration: Four high-capacity fixed and swivel casters (100–150 mm) rated to support 200–300 kg loads.
- Hygienic Detailing: Open longitudinal frame layout to minimize overspray buildup and ease chemical cleanings.
- Custom Options: 360-degree rotating top platform, integrated tool rails, task lighting, and collapsible hinges for storage.
Quick Reference Table
design specifications| Chassis Area | Legacy Equipment Problem | Proposed Engineering Solution | Operational Value Yield |
|---|---|---|---|
| Support Frame | Severe structural flexing under lopsided loads | Welded steel/aluminum RHS longitudinal beam grid | Maintains flat, deflection-free part transport |
| Trolley Wheels | Wheels lock up from paint overspray dust | High-load casters with sealed precision bearings | Ensures smooth, low-friction rolling inside cleanrooms |
| Chassis Finish | Chemical cleaners strip structural coatings | Industrial, mil-spec green rust-proof finish | Extends equipment lifespan and resists chemical corrosion |
| Frame Storage | Bulky frames block busy workshop routes | Integrated folding hinges and collapsible joints | Reclaims valuable cleanroom floor space when not in use |
Frequently Asked Questions
clarifying the design choicesWhy is steel RHS preferred over solid steel bars for the frame?
Solid bars are extremely heavy, making the trolley hard to push. Hollow RHS beams offer similar structural strength and bending resistance at a fraction of the weight.
How does the trolley design prevent overspray buildup?
We used an open, parallel beam grid instead of a solid flat deck. This allows sprayed paint to pass through the frame, reducing cleaning maintenance.
What specific benefits do sealed caster bearings provide?
Standard bearings capture floating paint dust and overspray, which quickly dry and seize the wheel. Sealed bearings block dust, ensuring smooth rolling over long shifts.
How does the collapsible frame design save workshop space?
The side supports use heavy-duty hinges. When the trolley is empty, operators can fold the frame flat and stack it against the cleanroom wall.
Can the trolley handle lopsided, irregularly shaped loads?
Yes. We added diagonal steel gussets to each corner. This reinforcement distributes off-center loads evenly across the chassis, preventing frame warping.
Why did this trolley project remain as a design proposal?
Although the mechanical concept and CAD models were fully validated, budget limitations at EPTEC delayed the physical build, leaving the design ready for future rollout.
Memory Hooks
mechanical tagsWelded hollow beams stop frame flexing without adding excess mass.
Specify closed bearings to prevent paint overspray from seizing wheels.
Use parallel frame cuts to let overspray pass through cleanly.
Incorporate heavy-duty hinges to reclaim valuable workshop floor space.
Practical Applications
industrial use-casesMilitary Paint Facilities
Providing heavy-duty, solvent-resistant parts carts for coating aerospace or marine components safely.
Body Assembly Lines
Using open, rigid trolley structures to transport engine parts and body panels between welding booths.
Shipyard Workshops
Deploying heavy-load, chemical-resistant carts to transport massive deck fittings across wet shipyards.
FEA Deflection Checks
Using structural CAD simulations to verify steel deflection ranges, protecting equipment from dynamic failure.
Centralized Control Panels
Using waistband push bars and locked caster brakes to ensure operators maneuver heavy carts safely.
Hygienic Steel Audits
Designing sloped, easy-to-clean profiles for industrial carts to minimize product dust trap zones.