BlockTalk Find Your Set

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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.

U.S.S. Constellation

Checking

10021 U.S.S. Constellation

975 pieces in 101 part and color combinations.

LEGO counts 973 pieces. This inventory comes from a separate parts catalog and lists 975; the two do not always count the same elements, so their totals differ. 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

Plates 518 pieces

  • Plate 1 x 1 Black Part 3024 Element 302426 ×26
  • Plate 1 x 2 Black Part 3023 Element 302326 ×68
  • Plate 1 x 3 Black Part 3623 Element 362326 ×20
  • Plate 1 x 4 Black Part 3710 Element 371026 ×24
  • Plate 1 x 6 Black Part 3666 Element 366626 ×18
  • Plate 1 x 8 Black Part 3460 Element 346026 ×45
  • Plate 2 x 2 Black Part 3022 Element 302226 ×18
  • Plate 2 x 3 Black Part 3021 Element 302126 ×21
  • Plate 2 x 4 Black Part 3020 Element 302026 ×12
  • Plate 2 x 6 Black Part 3795 Element 379526 ×21
  • Plate 2 x 8 Black Part 3034 Element 303426 ×42
  • Plate 4 x 10 Black Part 3030 Element 303076 or 303026 ×3
  • Plate 4 x 6 Black Part 3032 Element 303226 ×3
  • Plate 4 x 8 Black Part 3035 Element 303526 ×1
  • Plate 6 x 10 Black Part 3033 Element 303326 ×1
  • Plate 1 x 1 Light Gray Part 3024 Element 302402 ×26
  • Plate 2 x 4 Light Gray Part 3020 Element 302002 ×3
  • Plate 2 x 6 Light Gray Part 3795 Element 379502 ×4
  • Plate 1 x 1 Red Part 3024 Element 302421 ×2
  • Plate 1 x 2 Red Part 3023 Element 302321 ×3
  • Plate 1 x 4 Red Part 3710 Element 371021 ×3
  • Plate 1 x 6 Red Part 3666 Element 366621 ×2
  • Plate 2 x 2 Red Part 3022 Element 4613974 or 302221 ×2
  • Plate 2 x 4 Red Part 3020 Element 302021 ×2
  • Plate 2 x 8 Red Part 3034 Element 303421 ×4
  • Plate 4 x 6 Red Part 3032 Element 303221 ×1
  • Plate 4 x 8 Red Part 3035 Element 303521 ×1
  • Plate 6 x 8 Red Part 3036 Element 303671 or 303621 ×2
  • Plate 1 x 1 White Part 3024 Element 6548262 or 302401 ×10
  • Plate 1 x 2 White Part 3023 Element 6552100 or 6548261 ×22
  • Plate 1 x 3 White Part 3623 Element 6552105 or 6550144 ×6
  • Plate 1 x 4 White Part 3710 Element 6552108 or 6548266 ×18
  • Plate 1 x 6 White Part 3666 Element 6552107 or 6548265 ×20
  • Plate 1 x 8 White Part 3460 Element 6550141 or 346001 ×18
  • Plate 2 x 4 White Part 3020 Element 6552098 or 302001 ×4
  • Plate 2 x 6 White Part 3795 Element 6550146 or 379501 ×1
  • Plate 1 x 1 Yellow Part 3024 Element 302424 ×6
  • Plate 1 x 2 Yellow Part 3023 Element 302324 ×11
  • Plate 1 x 3 Yellow Part 3623 Element 362324 ×8
  • Plate 1 x 4 Yellow Part 3710 Element 371024 ×5
  • Plate 2 x 2 Yellow Part 3022 Element 4613978 or 302224 ×6
  • Plate 2 x 3 Yellow Part 3021 Element 302124 ×3
  • Plate 2 x 4 Yellow Part 3020 Element 302024 ×2

Bricks 199 pieces

  • Brick 1 x 1 Black Part 3005 Element 300526 ×36
  • Brick 1 x 2 Black Part 3004 Element 300426 ×40
  • Brick 1 x 3 Black Part 3622 Element 362226 ×6
  • Brick 1 x 4 Black Part 3010 Element 301026 ×11
  • Brick 1 x 6 Black Part 3009 Element 300926 ×3
  • Brick 1 x 8 Black Part 3008 Element 300826 ×6
  • Brick 2 x 10 Black Part 3006 Element 4617860 or 300626 ×5
  • Brick 2 x 2 Black Part 3003 Element 4103587 or 300326 ×2
  • Brick 2 x 3 Black Part 3002 Element 300226 ×11
  • Brick 2 x 4 Black Part 3001 Element 300126 ×6
  • Brick 2 x 8 Black Part 3007 Element 6037390 or 300726 ×16
  • Brick 1 x 1 Red Part 3005 Element 300521 ×2
  • Brick 1 x 2 Red Part 3004 Element 4613961 or 300421 ×6
  • Brick 1 x 4 Red Part 3010 Element 301021 ×1
  • Brick 1 x 6 Red Part 3009 Element 300921 ×3
  • Brick 1 x 8 Red Part 3008 Element 300821 ×3
  • Brick 2 x 8 Red Part 3007 Element 6036408 or 300721 ×2
  • Brick 1 x 1 White Part 3005 Element 6552096 or 6548258 ×6
  • Brick 1 x 2 White Part 3004 Element 6548257 or 4613964 ×16
  • Brick 2 x 2 White Part 3003 Element 6552095 or 6548256 ×16
  • Brick 2 x 4 White Part 3001 Element 6552094 or 300101 ×1
  • Brick 2 x 8 White Part 3007 Element 6619309 or 6033776 ×1

Bricks Round and Cones 60 pieces

  • Brick Round Corner 2 x 2 Macaroni with Stud Notch Black Part 3063b Element 306326 ×8
  • Brick Round 1 x 1 Open Stud Light Gray Part 3062b Element 306202 ×52

Bricks Sloped 54 pieces

  • Brick Sloped 45° 2 x 1 Double with Ovoid Bottom Pin Black Part 3044b Element 304426 ×3
  • Brick Sloped 45° 2 x 1 with Bottom Pin Black Part 3040b Element 4121966 or 304026 ×10
  • Brick Sloped 45° 2 x 2 Black Part 3039 Element 303926 ×1
  • Brick Sloped Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] Black Part 3660 Element 366026 ×6
  • Brick Sloped 45° 2 x 1 Double with Ovoid Bottom Pin Red Part 3044b Element 304421 ×1
  • Brick Sloped 45° 2 x 1 with Bottom Pin Red Part 3040b Element 4121934 or 304021 ×8
  • Brick Sloped 45° 2 x 2 Red Part 3039 Element 303921 ×12
  • Brick Sloped 45° 2 x 2 Double Red Part 3043 Element 304321 ×1
  • Brick Sloped Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] Red Part 3660 Element 366021 ×4
  • Brick Sloped Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] White Part 3660 Element 366001 ×8

Tiles 38 pieces

  • Tile 1 x 1 with Groove Black Part 3070b Element 307026 1 spare in the box ×38

Bars, Ladders and Fences 26 pieces

  • Fence Lattice 1 x 4 x 1 Black Part 3633 Element 4187209 or 363326 ×26

Plates Special 24 pieces

  • Plate Special 3 x 2 with Rounded End, Hole Black Part 3176 Element 317676 or 317626 ×6
  • Plate Special 1 x 2 with 1 Stud without Groove (Jumper) Light Gray Part 3794a Element 379402 ×12
  • Technic Plate 2 x 4 [3 Holes] Red Part 3709 Element 370921 ×4
  • Technic Plate 2 x 8 [7 Holes] Red Part 3738 Element 373821 ×2

Bricks Special 16 pieces

  • Brick Special 1 x 1 with Headlight Yellow Part 4070 Element 407024 ×16

Technic Bushes 15 pieces

  • Technic Bush Light Gray Part 3713 Element 4125313 or 659002 1 spare in the box ×15

Technic Bricks 6 pieces

  • Technic Brick 1 x 2 [1 Pin Hole] Black Part 3700 Element 370026 ×6

Hinges, Arms and Turntables 5 pieces

  • Hinge Plate 2 x 5 with Large Hole [Complete Assembly] Black Part 3149bc01 Element 4161112 or 4106943 ×1
  • Hinge Plate 2 x 9 with Hole Close to Hinge [Complete Assembly] Black Part 3324ac01 Element 4187212 or 4106945 ×2
  • Turntable 2 x 2 Plate - Top Light Gray Part 3679 Element 367952 or 367902 ×1
  • Turntable 2 x 2 Plate, Base Red Part 3680 Element 368021 ×1

Technic Axles 5 pieces

  • Technic Axle 10 Black Part 3737 Element 373726 ×3
  • Technic Axle 2 Notched Black Part 32062 Element 4109810 or 3206226 ×1
  • Technic Axle 4 Black Part 3705 Element 370526 ×1

Technic Connectors 2 pieces

  • Technic Axle and Pin Connector Light Gray Part 3651 Element 4105243 or 365102 ×2

Bricks Curved 1 piece

  • Brick Arch 1 x 4 Black Part 3659 Element 365926 ×1

Gear Parts 1 piece

  • Poster, U.S.S. Constellation (set 10021-1) [No Color/Any Color] Part 4191767 ×1

Minifig Heads 1 piece

  • Minifig Head [Plain] [Blocked Open Stud] Yellow Part 3626b ×1

Stickers 1 piece

  • Sticker Sheet for Set 10021-1 [No Color/Any Color] Part 45246 Element 4187376 ×1

String, Bands and Reels 1 piece

  • String Cord Medium Thickness 50cm Black Part 7916c50 ×1

Technic Pins 1 piece

  • Technic Axle Pin without Friction Ridges Lengthwise Light Gray Part 3749 Element 4184168 or 4154179 ×1

Wheels and Tyres 1 piece

  • Wheel with Split Axle hole Light Gray Part 3482 Element 348202 ×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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