Case study
Case study: SLA prototype pedals for Brompton Bicycles
We printed transparent-resin prototype pedals for Brompton Bicycles on SLA, with ±35 µm laser accuracy and a 1.5 µm Ra surface finish.
HenleyPrint3D engineering1 min readUpdated Published
Key takeaways
- Brompton Bicycles UK: transparent-resin SLA prototype pedals.
- ±35 µm laser accuracy.
- Surface finish of Ra 1.5 µm.
Suits
Product teams who need a clear, detailed prototype to check form, fit and internal geometry.
Worth knowing
Resin parts are more brittle than FDM or SLS, so use them for visual and fit checks.
The project
We produced transparent-resin prototype pedals for Brompton Bicycles UK on SLA. The laser holds ±35 µm, and the printed surface reaches Ra 1.5 µm, which is smooth enough to judge form and finish straight from the machine.
Key figures
| Item | Value |
|---|---|
| Customer | Brompton Bicycles UK |
| Part | Prototype pedals |
| Process | SLA, transparent resin |
| Laser accuracy | ±35 µm |
| Surface finish | Ra 1.5 µm |
Why SLA suited this part
SLA cures liquid resin with a UV laser, layer by layer, in layers from 10 microns. That gives fine detail and a smooth surface, and transparent resin lets engineers look through the part. Our standard SLA tolerance is ±0.5% with a minimum of ±0.1 mm, and the build volume is 350 × 250 × 250 mm. Read more in What is SLA 3D printing.
Process choice by prototype requirement
| If the prototype needs | Choose |
|---|---|
| Fine detail and a smooth surface | SLA |
| See-through internal geometry | SLA, transparent resin |
| Larger size or tougher parts | FDM |
| Functional nylon parts | SLS |
See the full Brompton Bicycles case study.
More on this work: consumer product design and 3D printed prototyping, plus our rapid prototyping guide.
Frequently asked questions
What accuracy does SLA reach?
On this project the laser accuracy was ±35 µm. Our standard quoted SLA tolerance is ±0.5% with a minimum of ±0.1 mm.
What surface finish did the pedals have?
Ra 1.5 µm.
Can resin be transparent?
Yes. Transparent resin suits light guides, flow models and prototypes where you need to see inside.
How fast can SLA parts be made?
Lead time starts from 1 calendar day.
Get started
Talk to an engineer about your part.
Send us your CAD or describe the problem. We recommend the process, material and finish, and quote with the lead time up front.
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