Services
Structural Design
Turning an approved form into a structure that assembles and manufactures: wall thickness, snap fits, bosses, tolerance chains and assembly sequence.
Structural design is the step that turns "looks right" into "assembles, survives use, and can be made". When surface data arrives, wall thickness may be uneven, snap fits may interfere, bosses may have nowhere to land. Problems not exposed here get exposed after the tool is cut, at an order of magnitude more cost.
Our output is not just data. It is data plus 2D drawings plus assembly sequence plus a tolerance-chain note. Those last three decide whether the shop floor can actually build it the way you intended.
Capabilities
- Deliverables
- Engineering data (STEP / native), 2D drawings, BOM, assembly sequence, DFM report
- Processes covered
- Injection moulding, sheet metal, CNC, die casting, silicone and hybrid structures
- Typical duration
- 2–4 weeks at moderate complexity, including one DFM revision round
- Analysis
- Interference checks, wall thickness and draft analysis, tolerance chain calculation
Solutions
Plastic parts
Even wall thickness, rib layout, snap fits and bosses balanced against strength and sink risk.
Sheet metal and machined structures
Bend sequence, minimum flanges, process holes and fastening arranged around real shop capability.
Assembly and tolerance
Fits are drawn as tolerance chains so we know which dimensions must be tight and which can be left open.
Process Overview
Structural design is a series of trade-offs: nearly every tightened dimension has a cost, every added feature a risk. We spend tolerance on the mating faces that actually drive function and leave the rest to general tolerance. Tightening the whole drawing looks rigorous; in practice it just raises cost and scrap together.
Tolerances & Size Limits
- General tolerance
- ISO 2768-m or as specified on the drawing
- Critical fits
- Called out individually and confirmed item by item at review
- Plastic shrinkage
- Allowed for by material shrink rate; tool corrected after first article measurement
Design Guide (DFM)
Keep wall thickness even
Abrupt changes are where sink and warp appear. Where strength is needed, add ribs rather than thickening everything.
Give snap fits room to flex
The snap can deflect, but surrounding structure has to let it. Otherwise it simply breaks on assembly.
Do not leave bosses isolated
A standalone boss sinks and snaps. Tie it back to a side wall with a rib.
Decide assembly sequence before structure
Sequence determines which faces must close first and which holes must align. Get it wrong and the structure will be reworked.
Leave one adjustable link in the chain
A stack of fits always accumulates deviation. One adjustable step is far cheaper than tightening every dimension.
Quality Control
- Interference and wall thickness analysis completed before drawings are released
- Critical fits calculated as tolerance chains rather than estimated
- Must-inspect dimensions marked on the 2D so inspection is not a full measure
- DFM report delivered with the data, risks written down rather than mentioned verbally
FAQ
We only have exterior surfaces. Can you work from that?
Yes — that is the normal starting point. We run a feasibility pass first and list the styling changes needed before starting.
Can we cut tooling straight from your data?
The data is built to tooling requirements, but we recommend a DFM sign-off with the tool shop first. They know their own equipment best.
Can you also run a small production batch?
Yes. Once structure is frozen we can move directly to CNC prototypes or rapid tooling, with the same team following through.
Need structural design? Send the drawing to an engineer.
First reply within 30 minutes during working hours (4 working hours at the latest); full quote and DFM feedback typically within 12 working hours.