Message Decoder (6831): parts list and STL files
Set 6831, Message Decoder, from 1989, has 34 pieces in 26 kinds of part and colour. Here is every part, with the ones you can 3D print at home and the ones to buy.
Get the free print filesFree: an STL file for every part you can print, the parts list and a BrickLink shopping list for the rest. Pro adds print-ready plates for a 256 mm bed and our printing guide. About ProYour Pro includes the print-ready plates.
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See the finished set (photo) on Rebrickable ↗
Buy the real set on Amazon ↗ We may earn a commission if you buy.
10 to print, 24 to buy, 2 spares. Print: plain bricks, plates and beams you can make on a home 3D printer. Buy: clear, printed, rubber, electric and very thin parts, which are better ordered. Spares are the extras in the box.
Every part in set 6831
| Colour | Part | Qty | Print or buy |
|---|---|---|---|
| Blue | 4070 Brick Special 1 x 1 with Headlight | 2 | |
| Black | 3020 Plate 2 x 4 | 1 | |
| Black | 3022 Plate 2 x 2 | 1 | |
| Blue | 3039 Brick Sloped 45° 2 x 2 | 1 | |
| Black | 3832 Plate 2 x 10 | 1 | |
| Blue | 3937 Hinge Brick 1 x 2 Base | 1 | |
| Black | 3938 Hinge Brick 1 x 2 Top Plate Thin | 1 | |
| Black | 4590 Plate Special 1 x 4 Offset with Bar Holes | 1 | |
| Blue | 4859 Wedge Plate 3 x 4 without Stud Notches | 1 | |
| Black | 4288 Wheel Balloon with Axle hole | 4 | Buy |
| Black | 122c01 Plate Special 2 x 2 with Wheels Red | 2 | Buy |
| Black | 298c02 Lever Small Base with Black Lever | 2 | Buy |
| Black | 3787 Wheel Arch, Mudguard 2 x 4 [Smooth] | 2 | Buy |
| Black | 3957a Antenna 1 x 4 with Rounded Top | 2 | Buy |
| Trans-Red | 4740 Dish 2 x 2 Inverted [Radar] | 2 | Buy |
| Trans-Red | 6141 Plate Round 1 x 1 with Solid Stud | 2 | Buy |
| Black | 3298pr0013 Brick Sloped 33° 3 x 2 with 'POLICE' Print (Space Police I) | 1 | Buy |
| Black | 4873 Bar 1 x 6 [Open Studs] | 1 | Buy |
| White | 2446 Helmet, Standard | 1 | Buy |
| Trans-Red | 2447 Headwear Accessory Visor For Standard Helmet | 1 | Buy |
| Yellow | 3626apr0001 Minifig Head Standard Grin Print [Solid Stud] | 1 | Buy |
| Black | 3838 Minifig Neckwear Airtanks | 1 | Buy |
| Black | 970c27 Hips and White Legs | 1 | Buy |
| White | 973c03h27pr0006 Torso, Classic Space Logo, Futuron Black Print, Black Arms, White Hands | 1 | Buy |
| Trans-Red | 2447 Headwear Accessory Visor For Standard Helmet | 1 spare | Buy |
| Black | 298c02 Lever Small Base with Black Lever | 1 spare | Buy |
Print set 6831 at home
The set tool makes an STL file for each of the 10 printable pieces, sorted by colour, plus a shopping list for the 24 to buy. Free, no account, and it runs on your own phone or computer.
Get the free print filesPro adds print-ready plates for a 256 mm bed. About Pro
Parts data: Rebrickable, and it can differ slightly from your box. Part shapes: LDraw Parts Library (CC BY 4.0). Browse all sets. Independent project, not sponsored, authorised or endorsed by any brick company.