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Injection-moulded canard sleeve for ST Engineering

A black injection-moulded sleeve for ST Engineering's storage canister: designed for moulding, mould made and samples measured, ahead of production.

Client
ST Engineering
Made for
ST Engineering Advanced Material Engineering, Singapore
Built for
Long storage inside a canister, under a constant load
The mould
Two side slides and push-plate ejection
Quote a moulding job (opens WhatsApp) Send a brief
Pieces quoted for production, over two years
Over 2,000
Samples in each trial round
10
Tolerance on the six critical dimensions
±0.1 mm
From mould release to the first moulded sleeves
About 4 weeks

What we brought

  1. What we can do

    From 3D printed parts to a production mould

    The sleeve began as 3D printed PC parts. When ST Engineering needed thousands, we moved it to injection moulding.

  2. How we look after you

    Every moulding detail agreed before steel is cut

    Gate, parting lines, ejection, sink and shrinkage were agreed on one drawing before the mould was released.

  3. What you get

    Samples checked against your critical dimensions

    We measured each sample round against the six critical dimensions and logged it in an inspection report.

The build

How we built it

5 steps, from the brief to the finished piece. Pick a step to jump to it.

The brief

Step 1 of 5 · 19/06/2026

Storage life
At least ten years, with low water absorption
Load
Holds its shape under a constant load of about 20 kg
Toughness
Good vibration, impact and wear resistance
Heat
Deflection temperature above 100 °C
Quantity
Over 2,000 pieces quoted for production, over two years

At Additive Inn, our 3D printing studio in Singapore, we deliver injection-moulded parts. ST Engineering asked us for a tough black sleeve to sit inside a storage canister. They had tested 3D printed versions and now needed thousands of pieces over two years.

Design for moulding

Step 2 of 5 · 22/07/2026

We consolidated the sleeve into one drawing, V8.2, with six critical dimensions held to ±0.1 mm. Our DFM review planned a single-cavity mould and checked sink, wall thickness and shrinkage before ST Engineering released it for tooling.

  1. Revision 0

    The six critical dimensions, each ±0.1 mm.

    DrawingRender +1 more

  2. Revision 0 · 17/07/2026

    ST Engineering approved V8.2 as the single design the mould would be made to.

  3. Revision 1 · 22/07/2026

    We agreed the gate, parting lines, push-plate ejection and a 1.02 shrink allowance, and the mould was released.

    Render +1 more

Making the mould

Step 3 of 5

We had the steel mould machined, wire cut and spark eroded, with copper electrodes for the fine features. The thin steel rib that forms the 2.5 mm fin slot was the most delicate part of the tool.

A steel mould block, ready for machining.
Wire EDM cutting a mould part.
Copper electrodes for the EDM work.
One half of the steel mould.
The mould half, polished.
Checking the cavity edges up close.

Samples and checks

Step 4 of 5 · 21/08/2026

The first moulded sleeves came off the tool in August. We checked each sample round against the critical dimensions, recorded it in a dimensional inspection report and looked over the gate mark in its shallow recess.

One of the first moulded sleeves.
The gate mark, in its recess.
Measuring a sample's length.

The final build

Step 5 of 5 · 05/10/2026

We delivered the moulded samples to ST Engineering for their own tests. Their load test called for a stiffer plastic, so the next round was PC-ABS, which held its shape after two days under load. Its height and diameter are now being tuned.

A round of ten moulded samples.

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