DLP solutions for TWS earbuds, custom in-ear monitors, hearing aids and hearing protection. Chambers, sound tubes and driver mounts are formed in one part — no draft angles and no tooling — running the same parameters from appearance validation to 10–500 unit batches.
Application scenarios
For the same kind of shell, TWS prioritises fit and batch consistency, HiFi prioritises acoustics and internal structure, and hearing aids prioritise contact safety. Different routes mean different materials, layer heights and finishing.
The chamber conforms to the concha and canal opening, balancing long-wear comfort with a recognisable look; case interfaces, magnet locations and contact clearances are formed with the shell.
Multi-driver chambers, crossover mounts and labyrinth sound tubes are formed in one piece, cutting bonding steps. Clear material turns internal structure into part of the exterior.
Canal geometry is rebuilt from ear-impression scans with left and right modelled separately; contact parts use biocompatible materials with matching batch documentation.
Sensors, batteries and PCBs must fit inside one shell. Open sandwich structures and cable channels are printed directly, so assembly order can change without tooling changes.
Capability support
These five capabilities run through everything from model to finished part, and are the areas we have validated repeatedly on hearables projects.
Surfaces are rebuilt from impression or intraoral scans, with continuous transitions across the concha, tragus and canal opening so pressure spreads and long wear stays comfortable.
Additive forming has no parting line or draft direction, so internal undercuts, thin-wall ribs, driver seats and threaded insert bores are built with the shell.
Sound tubes, damper grooves, front/rear chamber separation and pressure-relief ports are printed directly, reducing bond lines and the batch variation that assembly brings.
Clear, translucent, tough and high-temperature resins are selected by application; for ear-canal contact parts we recommend a medical-grade material with biocompatibility documentation and a stated use case.
Whole-layer exposure cures every part in the build together. 50 units and 500 units run the same slice parameters, the same post-processing sequence and the same inspection criteria.
The above describes process capability; achievable tolerance and surface depend on part structure and finishing requirements. We run a printability assessment before any order.
Route A
Design freedom
Injection moulding forces compromises on undercuts, recesses and complex parting. DLP has no such constraint: chamber tweaks, added or removed wings, local texture and edition differences are all a file change — with no tooling cost or modification cycle.
From appearance validation to small-batch supply, one model and one post-processing standard are used — avoiding the sample-versus-production mismatch.
Route B
Acoustic structure
Driver seats, crossover mounts and sound tubes are integrated into one shell, so assembly needs no repeated bonding or re-alignment and tube routing stays consistent across revisions.
Clear parts are affected by UV and sweat over time; we recommend anti-yellowing formulations and internal colouring by application, and itemise manual operations such as polishing in the quote.
Process scenarios
From plate layout and impression modelling to surface finishing, every stage affects final dimensions and appearance.
Whole-layer exposure cures every part together; layout is arranged by height and projected area to improve utilisation.
Shell surfaces are rebuilt from ear-impression or intraoral scans, modelled separately for left and right and delivered as a pair.
Sanding, blasting, polishing or coating are selected by application; clear parts can add polishing for transparency.
Hearables FAQ
Three options work: (1) STL from an ear-impression scan; (2) canal data exported from an intraoral scanner; (3) ship a silicone impression and we scan it. More complete data gives a more natural concha-to-canal transition; if data is partial we will say what is missing.
Critical dimensions are split by assembly function: driver seats and shell at ±0.05 mm, plug and snap fits with 0.1–0.15 mm clearance, other external dimensions at ±0.1 mm. The first article is trial-assembled, and slice parameters are locked for the batch once feel is approved.
Photopolymer resins gradually discolour under UV and sweat exposure — a material characteristic, not a process defect. We recommend anti-yellowing formulations, internal colouring or translucent alternatives by use case, with a comparison at sample stage so lifetime requirements can be assessed.
With complete files, standard hearables parts ship first articles in 24–48 hours including cleaning and post-cure, excluding manual operations such as polishing. Custom projects needing impression modelling or several fitting rounds are scheduled by agreed milestones.
Yes. DLP needs no tooling and can run a single build — from one piece. 10–500 units is our recommended small-batch range, where unit cost falls as plate utilisation improves, so submitting the full quantity at once is usually more economical.
We check wall thickness, minimum features, assembly clearance and support contact faces, then give material recommendations, unit price and lead time. Assessment and revision advice are free.