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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.

Build-A-Bob

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3826 Build-A-Bob

440 pieces in 116 part and color combinations, plus 1 minifigure.

The official piece count includes the 5 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.

Look-alike colors in this set

These parts appear in this set in two colors that are easy to confuse. If you are one short in one color, check whether it went in where the other color belongs. Each color has its own element ID in the parts list at the back of the instructions.

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Piece checklist

Yellow 208 pieces

  • Brick 1 x 1 Yellow Part 3005 Element 300524 ×18
  • Brick 1 x 10 Yellow Part 6111 Element 4200026 or 4192022 ×4
  • Brick 1 x 16 Yellow Part 2465 Element 4264963 or 246524 ×2
  • Brick 1 x 2 Yellow Part 3004 Element 4613966 or 300424 ×24
  • Brick 1 x 4 Yellow Part 3010 Element 301024 ×14
  • Brick 1 x 6 Yellow Part 3009 Element 300924 ×26
  • Brick 2 x 2 Yellow Part 3003 Element 4103588 or 300374 ×10
  • Brick 2 x 6 Yellow Part 2456 Element 4181143 or 245624 ×7
  • Brick Arch 1 x 6 x 2 - Thick Top with Reinforced Underside Yellow Part 3307 Element 330724 ×1
  • Brick Curved 1 x 2 x 1 1/3 with Curved Top Yellow Part 6091 Element 6388492 or 6361082 ×4
  • Brick Curved 2 x 4 x 1 1/3 Yellow Part 6081 Element 6388489 or 4204625 ×2
  • Brick Round 2 x 2 Dome Top, Blocked Open Stud, Bottom Axle Holder Yellow Part 30367b Element 4185784 ×1
  • Brick Round 2 x 2 with Axle Hole Yellow Part 3941 Element 614324 or 394124 ×6
  • Brick Sloped Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] Yellow Part 3660 Element 366024 ×10
  • Brick Sloped Inverted 75° 2 x 1 x 3 Yellow Part 2449 Element 6546481 or 6146485 ×32
  • Brick Special 1 x 1 with Headlight Yellow Part 4070 Element 407024 ×6
  • Hinge Brick 1 x 2 Base Yellow Part 3937 Element 393724 ×1
  • Hinge Plate 1 x 2 Locking with 1 Finger On End, with Groove Yellow Part 44301a Element 4588025 or 4295303 ×2
  • Hinge Plate 1 x 2 Locking with 2 Fingers On End, with Groove, 9 Teeth Yellow Part 44302a Element 4183981 ×4
  • Plate 1 x 2 Yellow Part 3023 Element 302324 ×3
  • Plate 1 x 6 Yellow Part 3666 Element 366624 ×6
  • Plate 2 x 6 Yellow Part 3795 Element 379524 ×4
  • Plate 4 x 6 Yellow Part 3032 Element 303224 ×4
  • Plate 6 x 10 Yellow Part 3033 Element 303324 ×3
  • Plate Special 3 x 2 with Rounded End, Hole Yellow Part 3176 Element 4188313 or 4141738 ×1
  • Plate Special 6 x 12, Studs on 3 Edges Yellow Part 6178 Element 4542680 or 4295304 ×2
  • Technic Brick 1 x 6 [5 Pin Holes] Yellow Part 3894 Element 389424 ×1
  • Technic Brick Special 2 x 2 with Axle Hole, Rotation Joint Ball Half [Vertical Side], Vertical Axle Hole End Yellow Part 47431 Element 4218234 ×2
  • Technic Brick Special 2 x 3 with Pin Holes, Rotation Joint Ball Half [Horizontal Top], Rotation Joint Socket Yellow Part 47454 Element 4218105 ×2
  • Technic Rotation Joint Ball Loop with Two Perpendicular Pins with Friction Yellow Part 47455 Element 6518951 or 4220498 ×4
  • Tile 1 x 2 with Groove Yellow Part 3069b Element 306924 ×2

Black 82 pieces

  • Brick 1 x 1 Black Part 3005 Element 300526 ×8
  • Brick 1 x 2 Black Part 3004 Element 300426 Also in Dark Bluish Gray ×6
  • Brick 1 x 6 Black Part 3009 Element 300926 ×2
  • Brick 2 x 2 Black Part 3003 Element 4103587 or 300326 ×4
  • Brick 2 x 2 Corner Black Part 2357 Element 235776 or 235726 ×4
  • Brick Curved 6 x 1 Black Part 42022 Element 4160393 ×4
  • Brick Curved 6 x 2 Black Part 44126 Element 4180548 ×2
  • Brick Round Corner 2 x 2 Macaroni with Stud Notch Black Part 3063b Element 306326 ×8
  • Brick Round Corner 4 x 4 Full Brick Black Part 2577 Element 6188426 or 6078094 ×4
  • Brick Round Corner 4 x 4 Macaroni Wide with 3 Studs Black Part 48092 Element 6252902 or 6173190 ×4
  • Brick Sloped 45° 2 x 1 with Bottom Pin Black Part 3040b Element 4121966 or 304026 ×4
  • Brick Sloped 45° 2 x 2 Black Part 3039 Element 303926 ×4
  • Brick Wedged, Angled 4 x 2 Left Black Part 41768 Element 6078889 or 4644755 ×4
  • Brick Wedged, Angled 4 x 2 Right Black Part 41767 Element 6078886 or 4644754 ×4
  • Dish 2 x 2 Inverted [Radar] Black Part 4740 Element 474026 ×1
  • Lever Small Base with Black Lever Black Part 298c02 Element 73587 1 spare in the box ×6
  • Plate Special 1 x 2 [Side Handle Closed Ends] Black Part 48336 Element 4225201 ×1
  • Technic Axle 10 Black Part 3737 Element 373726 ×2
  • Technic Axle 4 Black Part 3705 Element 370526 ×1
  • Technic Axle and Pin Connector Angled #1 Black Part 32013 Element 6284699 or 4107085 ×1
  • Technic Axle and Pin Connector Angled #2 - 180° Black Part 32034 Element 6271869 or 4107783 ×1
  • Technic Gear 36 Tooth Double Bevel Black Part 32498 Element 4255563 or 4177434 ×1
  • Tile 1 x 6 with Groove Black Part 6636 Element 663626 ×4
  • Tile Special 1 x 1 with Clip and Straight Tips Black Part 2555 Element 255526 ×2

White 42 pieces

  • Brick 1 x 12 White Part 6112 Element 6548281 or 611201 ×2
  • Brick 1 x 4 White Part 3010 Element 6550135 or 301001 ×5
  • Brick 1 x 6 White Part 3009 Element 6552097 or 6548259 ×2
  • Brick 2 x 6 White Part 2456 Element 6552122 or 4249698 ×2
  • Brick Round 2 x 2 with Axle Hole White Part 3941 Element 6601920 or 614351 ×6
  • Brick Sloped 45° 2 x 2 with Radar Screen Print White Part 3039pr0005 Element 4261941 or 82024 ×1
  • Dish 8 x 8 Inverted [Radar] with Medium Blue Circle with Black Center Print White Part 3961pr0011 Element 4293538 ×2
  • Hinge Brick 1 x 2 Top Plate Thin White Part 3938 Element 393801 ×1
  • Minifig Head [Plain] [Blocked Open Stud] White Part 3626b ×2
  • Plate 1 x 2 White Part 3023 Element 6552100 or 6548261 ×3
  • Plate 1 x 4 White Part 3710 Element 6552108 or 6548266 ×1
  • Plate 2 x 2 White Part 3022 Element 6552099 or 6548260 ×4
  • Plate 2 x 4 White Part 3020 Element 6552098 or 302001 ×2
  • Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) White Part 4032a Element 6601914 or 403201 ×4
  • Technic Brick Special 2 x 2 with Pin Hole, Rotation Joint Socket White Part 48169 Element 6328452 or 4218483 ×2
  • Tile 1 x 2 with Computer Keyboard Standard Print White Part 3069bpr0030 Element 4293350 ×1
  • Wedge Plate 3 x 2 Left White Part 43723 Element 6552121 or 4179875 ×1
  • Wedge Plate 3 x 2 Right White Part 43722 Element 6552120 or 4179874 ×1

Dark Bluish Gray 27 pieces

  • Brick 1 x 2 Dark Bluish Gray Part 3004 Element 4211088 Also in Black ×7
  • Panel 1 x 4 x 1 with Rounded Corners [Thick Wall] Dark Bluish Gray Part 43337 Element 6092647 or 4267940 ×1
  • Plate 2 x 8 Dark Bluish Gray Part 3034 Element 4210997 ×2
  • Plate 4 x 4 Dark Bluish Gray Part 3031 Element 4243831 or 4211089 ×2
  • Plate Round Corner 3 x 3 Dark Bluish Gray Part 30357 Element 4212075 ×4
  • Plate Round Corner 4 x 4 Dark Bluish Gray Part 30565 Element 4222042 ×4
  • Technic Axle 3 with Stud Dark Bluish Gray Part 6587 Element 6587199 or 6129590 ×2
  • Tile 1 x 4 with Train Controls Print Dark Bluish Gray Part 2431pr0028 Element 6020825 or 4215740 ×1
  • Wedge Plate 4 x 2 Left Dark Bluish Gray Part 41770 Element 4210788 ×2
  • Wedge Plate 4 x 2 Right Dark Bluish Gray Part 41769 Element 4210782 ×2

Reddish Brown 25 pieces

  • Brick 1 x 12 Reddish Brown Part 6112 Element 4222627 ×4
  • Brick 1 x 2 Reddish Brown Part 3004 Element 4613963 or 4211149 ×6
  • Brick 1 x 4 Reddish Brown Part 3010 Element 4211225 ×8
  • Brick Round 4 x 4 with 4 Side Pin Holes and Center Axle Hole Reddish Brown Part 6222 Element 6177805 or 4223681 ×2
  • Plate 2 x 6 Reddish Brown Part 3795 Element 4211247 ×3
  • Plate 6 x 6 Reddish Brown Part 3958 Element 4217848 ×2

Red 18 pieces

  • Brick Special 1 x 4 with 4 Studs on One Side Red Part 30414 Element 4177991 or 4157223 ×3
  • Lever Small Base with Black Lever Red Part 298c02 Element 74335 1 spare in the box ×1
  • Plate 1 x 6 Red Part 3666 Element 366621 ×1
  • Plate 2 x 6 Red Part 3795 Element 379521 ×1
  • Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) Red Part 4032a Element 403221 ×3
  • Plate Special 1 x 1 with Clip Light, Bar Hole [Thick Ring] Red Part 4081b Element 6281994 or 4632572 ×2
  • Technic Axle 2 Notched Red Part 32062 Element 4142865 ×1
  • Tile 2 x 2 with Groove Red Part 3068b Element 306821 ×2
  • Wedge Plate 3 x 2 Left Red Part 43723 Element 4372321 or 4180533 ×2
  • Wedge Plate 3 x 2 Right Red Part 43722 Element 4372221 or 4180504 ×2

Light Bluish Gray 16 pieces

  • Brick 2 x 2 Light Bluish Gray Part 3003 Element 4211387 ×3
  • Brick 2 x 4 Light Bluish Gray Part 3001 Element 4211385 ×2
  • Brick 4 x 6 Light Bluish Gray Part 2356 Element 4217371 ×2
  • Tap 1 x 1 with Hole in Spout Light Bluish Gray Part 4599a ×1
  • Technic Bush 1/2 Smooth with Axle Hole Reduced Light Bluish Gray Part 32123a 1 spare in the box ×2
  • Technic Gear 12 Tooth Double Bevel Light Bluish Gray Part 32270 Element 32270194 or 4211634 ×2
  • Technic Gear 20 Tooth Double Bevel with Axle Hole Type 2 [X Opening] Light Bluish Gray Part 32269 Element 32269194 or 4211635 ×1
  • Tile Special 1 x 2 Grille with Bottom Groove Light Bluish Gray Part 2412b Element 4211350 ×3

Tan 10 pieces

  • Technic Axle Pin without Friction Ridges Lengthwise Tan Part 3749 Element 4666579 or 4186017 ×2
  • Technic Brick 1 x 2 [1 Pin Hole] Tan Part 3700 Element 4205107 or 370005 ×8

Blue 5 pieces

  • Brick Special 2 x 2 with 2 Pins and Axle Hole Blue Part 30000 Element 3000023 ×2
  • Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) Blue Part 4032a Element 403223 ×2
  • Technic Rubber Belt Medium [26mm ID] [Round Cross Section] Blue Part 85545 Element 6049730 or 4544147 ×1

Trans-Clear 4 pieces

  • Hat, Chef / Baker Trans-Clear Part 3898 Element 4640921 or 4292835 ×4

Trans-Dark Blue 1 piece

  • Plate Round 1 x 1 with Solid Stud Trans-Dark Blue Part 6141 Element 6514055 or 6240214 1 spare in the box ×1

Trans-Yellow 1 piece

  • Plate Round 1 x 1 with Solid Stud Trans-Yellow Part 6141 Element 6514056 or 6240216 1 spare in the box ×1

[No Color/Any Color] 1 piece

  • Sticker Sheet for Set 3826-1 [No Color/Any Color] Part 56215 Element 4294107 ×1

Minifigures 1 figure

  • Plankton 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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