GETMILK

Polaris — Tactile Star Map for Blind Astronomers

A 3D-printed and resin-cast star chart that lets blind and low-vision astronomers read the night sky with their fingertips, with each major constellation paired to a sound and a Braille caption. Designed with — not for — students from the Lisbon school for the blind.

complexity: mediumtolerance: precision
Polaris — Tactile Star Map for Blind Astronomers

Snapshot

Feasibility at a glance

PT localization

10/10

Full

The whole build can be sourced in Portugal.

Per unit

€95–€160 per map

at 300-unit volume

Starter batch

300units

minimum viable run

To first batch

12weeks

6 phases, design to ship

Budget

€29K–€67K

all-in estimate

Bottom line

Reproject Hipparcos catalogue into the disc's frame at the chosen epoch.
Read full insight

Picked based on the localization score (10/10) plus the dominant process (sla printing). For an early build at this batch size, this gives you the best balance of cost, risk, and speed of iteration.

What it does

4 capabilities

Lets the reader feel the geometry of every visible constellation.

Speaks the name and story of any star they touch through bone conduction.

Switches between northern and southern hemispheres with one disc swap.

Pairs with a school-grade telescope so a blind student can guide a sighted partner.

How it's made

4 stations · build route

  1. 1

    Plot the sky

    Reproject Hipparcos catalogue into the disc's frame at the chosen epoch.

  2. 2

    Print the relief

    SLA print the master, then cast in pigmented epoxy for a tougher finish.

  3. 3

    Wire the audio

    Capacitive touch under each star, mapped to a short narrated clip.

  4. 4

    Co-design with users

    Every prototype goes back to the students before the next revision.

Risks to watch

3 identified · 0 blocking

3 medium

Medium

Buyer doesn't recognise the category

An unusual product needs unusual education before it sells.

Mitigation — Ship 50 units to lighthouse customers free for the first quarter.

Medium

Fragile / temperature-sensitive shipping

Bio / consumable products need controlled shipping that small couriers skip.

Mitigation — Build a corrugated insulation insert and fly your own first 20 boxes.

Medium

Open-design drift dilutes the brand

Other makers will fork the design — you need a moat that isn't the file.

Mitigation — Sell the cartridge / refill / service, not the device.

Production timeline

12 weeks to first batch

wk 1wk 7

SLA 3D printing

wk 1–2

Casting

wk 3

Laser cutting

wk 4

FDM 3D printing

wk 5

Soldering

wk 6

Functional QA & batch sign-off

wk 7

wk 1–2 is the longest stretch — SLA 3D printing takes 2 weeks of the 7 weeks on this build.

What goes into it

5 materials · 6 processes

Materials

Pigmented epoxy resinWalnut wood frameRecycled brass studsConductive carbon inkPiezo audio driver

Processes

sla_printingcastinglaser_cuttingfdm_printingsolderingfinal_assembly

Design philosophy and best practices

5 principles

A tactile star map must be easy to read by touch, durable under daily handling and paired with clear audio. Dot size, spacing and contrast for touch decide usability more than visual looks.

1

Follow tactile graphics guidelines

Use spacing and dot heights similar to braille conventions so features are distinct under the fingertip.

2

Use a few textures, clearly different

Too many textures confuse. Separate stars, constellation lines and planets by height and feel.

3

Make touch zones match audio

Touch-sensitive points on the rim must line up with the right audio clip.

4

Choose wear-resistant surfaces

Resin and brass must keep their shape after years of touching.

5

Test with blind users

Testing with real readers finds problems early.

Common pitfalls

Avoid

Dots too close together to tell apart.

Avoid

Sharp edges from printing or casting.

Avoid

Audio that is hard to hear or too slow to respond.

Avoid

Wood frames moving with humidity and loosening the disc.

10-year evolution forecast (2026-2036)

4 phases

Accessible science tools are growing in museums and schools. The points below are trends.

2026–2028

Printed tactile models

Trend: 3D printing makes custom tactile materials cheaper.

2028–2031

Audio and touch together

Trend: tactile models combined with audio guides.

2031–2034

Accessibility rules

Trend: the European Accessibility Act raises expectations for accessible products.

2034–2036

Shared design libraries

Trend: open libraries of tactile designs spread.

Outlook

Expect demand from museums, planetariums and schools wanting accessible exhibits.

Materials intelligence

5 materials

Pigmented epoxy resin

Medium supply risk

Constellation disc

Sourced from: Epoxy is made by chemical companies in Europe, the US and Asia.

Walnut wood

Low supply risk

Frame

Sourced from: Walnut comes from Europe and North America.

Recycled brass

Low supply risk

Star studs

Sourced from: Brass is recycled widely in Europe.

Conductive carbon ink

Low supply risk

Touch sensing traces

Sourced from: Made by ink producers in Europe, the US and Asia.

Piezo audio driver

Low supply risk

Sound output

Sourced from: Mostly made in China and Japan.

Prototyping and rapid manufacturing in Portugal

4 companies from the atlas

3DWays

Oeiras

SLA and FDM printing

Master patterns for the constellation disc.

FAN3D

FDM printing

Rim housing prototypes.

DIB4T

Marinha Grande

Laser cutting and assembly

Cutting frame parts and templates.

Systion Electronics

Setúbal

Electronics soldering

Audio rim wiring.

462 Portuguese manufacturers matched

None cover the whole build — it splits across steps.