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LEGO Missing Piece Checker

Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece and leave with the element ID LEGO asks for, or a link to buy the part.

Tripod Invader

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7051 Tripod Invader

159 pieces in 58 part and color combinations, plus 2 minifigures.

The official piece count includes the 7 parts inside the set's minifigures, which this inventory lists separately. Spare parts are counted in neither figure.

Before you call it missing

Builders who report a missing piece often find it in one of these places. Tick each one off as you look.

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Piece checklist

Technic Pins 21 pieces

  • Technic Pin with Friction Ridges Lengthwise and Center Slots Black Part 2780 Element 4121715 or 278026 1 spare in the box ×18
  • Technic Pin 1/2 without Friction Ridges Blue Part 4274 Element 4143005 1 spare in the box ×1
  • Technic Pin 1/2 with 2L Bar Extension Light Bluish Gray Part 61184 Element 6347715 or 4520320 ×2

Plates Special 19 pieces

  • Plate Special 1 x 1 with Clip Horizontal [Thick Open O Clip] Black Part 61252 Element 6308000 or 4517925 ×5
  • Plate Special 1 x 2 with Clips Horizontal [Open O Clips] Black Part 60470b Element 6310268 or 4556158 ×1
  • Plate Special 3 x 2 with Rounded End, Hole Dark Bluish Gray Part 3176 Element 4225733 ×1
  • Cylinder Hemisphere 2 x 2 Ball Turret Socket Base Light Bluish Gray Part 44358 Element 6249936 or 4211801 ×1
  • Plate Special 1 x 2 Side Handle [Free Ends] Light Bluish Gray Part 2540 Element 4211632 ×3
  • Plate Special 1 x 2 with Clip Horizontal on End Light Bluish Gray Part 63868 Element 6319336 or 4535738 ×2
  • Plate Special 1 x 2 with 1 Stud without Groove (Jumper) Lime Part 3794a Element 4160084 ×6

Technic Connectors 16 pieces

  • Technic Axle and Pin Connector Perpendicular Double Split Black Part 41678 Element 4162857 ×6
  • Technic Connector Block 3 x 3 Triangular with Axle, and Axle Hole Black Part 58177 Element 4497946 ×3
  • Technic Axle Connector Hub with 3 Axles at 120° Light Bluish Gray Part 57585 Element 4502595 ×1
  • Technic Axle Connector Smooth [with x Hole + Orientation] Light Bluish Gray Part 59443 Element 4512360 ×3
  • Technic Axle and Pin Connector Angled #6 - 90° Light Bluish Gray Part 32014 Element 6268924 or 4509886 ×3

Plates 13 pieces

  • Plate 2 x 8 Black Part 3034 Element 303426 ×1
  • Plate 6 x 6 Dark Bluish Gray Part 3958 Element 4211134 ×1
  • Plate 2 x 3 Light Bluish Gray Part 3021 Element 4211396 ×4
  • Plate 1 x 2 White Part 3023 Element 6552100 or 6548261 ×7

Technic Axles 11 pieces

  • Technic Axle 4 with Stop Dark Bluish Gray Part 87083 Element 6083620 or 4560177 ×2
  • Technic Axle 8 with Stop Dark Bluish Gray Part 55013 Element 4499858 ×3
  • Technic Axle 2 Notched Red Part 32062 Element 4142865 ×6

Plates Round Curved and Dishes 10 pieces

  • Dish 6 x 6 Inverted, Radar / Webbed [Anti-studs at 90°] Black Part 4285b Element 6603362 or 4509865 ×3
  • Plate Round 1 x 1 with Solid Stud Dark Purple Part 6141 Element 4566522 1 spare in the box ×5
  • Plate Round 4 x 4 with Pin Hole Light Bluish Gray Part 60474 Element 4515351 ×1
  • Plate Round 1 x 1 with Solid Stud Trans-Neon Green Part 6141 Element 6240223 or 3005749 1 spare in the box ×1

Bricks Special 8 pieces

  • Brick Special 1 x 2 with Grille Dark Bluish Gray Part 2877 Element 4210636 ×2
  • Brick Special 1 x 4 with 4 Studs on One Side Light Bluish Gray Part 30414 Element 4211636 ×3
  • Brick Special 2 x 2 with Pin and Axle Hole Light Bluish Gray Part 6232 Element 6347704 or 4211529 ×3

Bricks Round and Cones 7 pieces

  • Brick Round 2 x 2 [Grill] Light Bluish Gray Part 92947 Element 4650645 or 4610816 ×1
  • Brick Round Corner 6 x 6 with 33° Slope and Facet Cutout Light Bluish Gray Part 95188 Element 6588816 or 6063878 ×2
  • Dome Hemisphere 3 x 3 Ball Turret Light Bluish Gray Part 44359 Element 6249938 or 4529550 ×2
  • Cone 1 x 1 [Top Groove] Trans-Neon Green Part 59900 Element 6301321 or 6172230 ×2

Technic Bricks 7 pieces

  • Technic Brick 1 x 2 [2 Pin Holes] Dark Bluish Gray Part 32000 Element 4210762 ×3
  • Technic Brick 1 x 2 [1 Pin Hole] Light Bluish Gray Part 3700 Element 4211440 ×3
  • Technic Brick 1 x 2 with Axle Hole Type 1 [+ Opening] and Bottom Pin Red Part 32064a Element 6196217 or 4513987 ×1

Bricks Curved 6 pieces

  • Brick Curved 3 x 1 No Studs Dark Purple Part 50950 Element 6103449 or 4578772 ×6

Bricks Sloped 6 pieces

  • Brick Sloped Inverted 33° 3 x 2, Connections between Studs, Ovoid Bottom Pin Black Part 3747b Element 4500458 or 374726 ×3
  • Brick Sloped 45° 2 x 2 Dark Bluish Gray Part 3039 Element 4211054 ×2
  • Brick Sloped Inverted 45° 4 x 2 Double with 2 x 2 Recessed Dark Bluish Gray Part 4871 Element 4211076 ×1

Technic Special 6 pieces

  • Technic Link 1 x 9 Bent (6 - 4) Black Part 64451 Element 4539296 ×6

Technic Bushes 5 pieces

  • Technic Bush Light Bluish Gray Part 3713 Element 6275844 or 6271817 1 spare in the box ×5

Technic Gears 5 pieces

  • Technic Driving Ring Extension, 4 Ridges Light Bluish Gray Part 32187 Element 4278756 or 4209329 ×2
  • Technic Worm Gear Light Bluish Gray Part 4716 Element 4211510 ×3

Minifig Shields, Weapons, & Tools 4 pieces

  • Weapon Gun Ray / Sci Fi Flat Silver Part 87993 Element 4625812 ×1
  • Weapon Spike Flexible 3.5L Lime Part 64727 Element 4616843 ×3

Bars, Ladders and Fences 3 pieces

  • Lever Small Base with Black Lever Red Part 298c02 Element 74335 1 spare in the box ×2
  • Antenna 1 x 4 with Rounded Top Trans-Neon Green Part 3957a ×1

Windscreens and Fuselage 3 pieces

  • Windscreen 6 x 4 x 2 1/3 Bubble Canopy with Handle Trans-Bright Green Part 87752 Element 6544550 or 4563482 ×2
  • Windscreen 6 x 6 x 3 Canopy Half Sphere with Dual 2 Fingers Trans-Clear Part 50747 Element 4624369 or 4530764 ×1

Bricks Wedged 2 pieces

  • Brick Wedged, Curved 10 x 3 Left Light Bluish Gray Part 50955 Element 4505087 ×1
  • Brick Wedged, Curved 10 x 3 Right Light Bluish Gray Part 50956 Element 4505088 ×1

Tiles 2 pieces

  • Tile 1 x 2 with Groove Light Bluish Gray Part 3069b Element 4211414 ×2

Bricks 1 piece

  • Brick 2 x 4 Black Part 3001 Element 300126 ×1

Hinges, Arms and Turntables 1 piece

  • Hinge Tile 1 x 4 Locking Dual 1 Fingers on Top [8 Locking Ridges] Lime Part 95120 Element 4622571 ×1

Minifig Accessories 1 piece

  • Bag / Briefcase Reddish Brown Part 4449 Element 6268857 or 4211235 ×1

Minifig Headwear 1 piece

  • Headwear, Clinger (Alien Invader) Lime Part 95204pr0001 Element 6021092 or 4646511 ×1

Stickers 1 piece

  • Sticker Sheet for Set 7051-1 [No Color/Any Color] Part 96171 Element 4653111 ×1

Minifigures 2 figures

  • Alien Trooper Minifigure, checked as a whole figure ×1
  • Man, Dark Blue Pinstripe Suit with Gold Tie, Black Hair, Glasses, 3626cpr0792 Minifigure, checked as a whole figure ×1

Tick each piece as you find it, or mark it missing.

When a piece really is missing

Ask LEGO

LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for the set number and each piece's element ID, the number printed beside the piece in the parts list at the back of the instructions. This checker lists both.

Request a replacement from LEGO

Buy the piece

Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from older or second-hand sets.

Keep a record

Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.

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