Chassis, Machine Frame & Baseframe Fabrication
Contents
- Chassis, Machine Frame & Baseframe Fabrication
- Materials for Base Frames
- Applications of Base Frames
- Fabrication Steps of Baseframes and Chassis
- Dimensional Drift in Welded Base frames
- Case Study : Oversized Machine Chassis
- Case Study 2: Cost Optimisation in Frame Design
- Case Study 3: Planning for Hot-Dip Galvanised Hollow Base frames
- How can we help you ?
Chassis & Base Frame Fabrication refers to the production of a structural framework or base component that serves as the foundation or support for a larger system, device, or equipment. These base frames are commonly used in various industries to provide structural integrity, ensure stability, and house components or machinery.
Materials for Base Frames
Fabrication Steps of Baseframes and Chassis
Dimensional Drift in Welded Base frames
Background
During a fabrication project at Novelty Structures, an initial manufacturing sequence resulted in unexpected dimensional movement after final machining. The original plan was to complete welding, send the baseframe for thermal stress relief, and then execute all machining operations. However, removing significant amounts of metal during final machining reintroduced secondary stresses and altered the final tolerances.
The Solution & Sequence Optimization
Novelty Structures revised the manufacturing route to split machining into two distinct stages, placing thermal stress relief between rough cutting and final finishing:
Original Sequence
Revised Best-Practice Sequence:
By rough machining first, the bulk of material removal and its associated stresses took place before heat treatment. Thermal stress relief then stabilised both the weldment and the rough-machined surfaces, leaving only light finishing cuts to achieve the exact final geometry. This process aligns with established heat-treatment guidance, which recommends stress relieving after rough machining to minimise post-finishing movement.
Case Study : Oversized Machine Chassis
Background
When designing large-scale structural frames—such as an 18-metre long, 4-metre wide machine support cradle—a single-piece frame creates severe manufacturing, coating, and transport bottlenecks. While structurally sound on paper, single-piece frames often exceed road transport limits, galvanising bath sizes, and machine shop capacities.
The Solution & Process Optimisation
Novelty Structures addresses large frame design by dividing the structure into manageable, transportable modules with structural bolted splice joints. To overcome potential alignment challenges during site installation, trial assemblies are performed in the workshop before dispatch.
Production Route Checklist
Before finalising module dimensions and connection details, Novelty Structures evaluates the design against every stage of the manufacturing journey:
| Production Stage | Engineering Design Considerations |
|---|---|
| Fabrication & Handling | Module weight, centre of gravity, lifting lug locations, and turning clearance during welding. |
| Machining | Machine bed envelope, table load limits, tool access, and clamping clearance—not just nominal frame size. |
| Galvanising | Kettle dimensions, dipping orientation, suspension points, and internal venting/drainage. |
| Surface Coating | Access for grit blasting, paint spray clearance, and curing oven dimensions. |
| Transport & Delivery | Transport envelope, route height/width restrictions, crane offloading limits, and site access. |
| Final Assembly | Joint access, reference datums, bolt torque access, and final alignment verification. |
Case Study 2: Cost Optimisation in Frame Design
Background
On complex chassis projects, applying tight tolerances uniformly across an entire fabrication significantly drives up manufacturing costs. In many cases, a complete multi-ton frame must be secured on an ultra-large CNC machining centre simply to finish a few small mounting pads.
The Solution & Process Optimization
Novelty Structures isolates critical functional interfaces from surrounding structural components. By concentrating precision machining strictly on defined mounting surfaces, the overall frame remains in a standard fabricated condition without compromising machinery performance.
Tolerance Allocation Review Framework
| Frame Feature | Evaluation Metric | Strategic Design Action |
|---|---|---|
| Equipment Mounting Pads | Which surfaces require controlled flatness, height, or alignment? | Machine raised pads only, keeping surrounding frame unmachined. |
| Locating Bores & Holes | Which holes position equipment vs. providing clearance? | Precision-bore critical alignment points; use clearance holes for fasteners. |
| Outer Frame Boundaries | What variance can surrounding installation space accept? | Apply standard structural steel fabrication tolerances. |
| Non-Contact Surfaces | Is machining functionally necessary for operation? | Retain approved as-welded or coated finish without post-weld cutting. |
Case Study 3: Planning for Hot-Dip Galvanised Hollow Base frames
Background
A fully welded hollow-section baseframe met all structural and dimensional requirements but required unexpected shop-floor modifications before hot-dip galvanising. Sealed tubular members, capped ends, and internal partition plates lacked proper venting and drainage openings.
The Solution & Process Optimisation
During hot-dip galvanising at ~450°C, trapped air inside closed sections expands rapidly, posing safety risks, while trapped cleaning acids prevent zinc coverage. Novelty Structures incorporates internal venting and drainage detailing directly into the 3D model stage in accordance with industry galvanising design guidelines.
Hollow-section venting and drainage
Galvanising Review Checklist
How can we help you ?
Chassis and baseframe fabrication services are indispensable to various industries and their success depends on the careful selection of fabrication suppliers.
Novelty Structures stands out as a reliable partner in providing high-quality machine frame and baseframe fabrication services tailored to demanding industrial needs.
