Heavy-Duty Excavator (42121): parts list and STL files

Set 42121, Heavy-Duty Excavator, from 2021, has 569 pieces in 131 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 files

Free: 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.

Need filament? Find PLA on Amazon. We may earn a commission if you buy.

Heavy-Duty Excavator, built (3D picture) — What it looks like built. A 3D picture, not a photo, made from the LDraw model by Philippe Hurbain (CC BY 2.0).

See the finished set (photo) on Rebrickable ↗

Buy the real set on Amazon ↗ We may earn a commission if you buy.

562to print

7to buy

20spares

131kinds

562 to print, 7 to buy, 20 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 42121

Parts in set 42121, Heavy-Duty Excavator
Colour	Part	Qty	Print or buy
Black	15379 Link Tread with Beveled Edge	86	Print
Blue	42924 Pin Long with Friction Ridges Lengthwise, 1 Center Slot	63	Print
Black	61332 Pin with Friction Ridges Lengthwise with No Center Slots	38	Print
Dark Bluish Gray	60483 Beam 1 x 2 Thick with Pin Hole and Axle Hole	20	Print
Light Bluish Gray	4274 Pin 1/2 without Friction Ridges	15	Print
Blue	43093 Axle Pin with Friction Ridges Lengthwise	14	Print
Light Bluish Gray	4519 Axle 3	13	Print
Black	18651 Axle Pin 3L with Friction Ridges Lengthwise and 2L Axle	12	Print
Reddish Brown	24316 Axle 3 with Stop	10	Print
Black	41677 Beam 1 x 2 Thin	10	Print
Black	6536 Axle and Pin Connector Perpendicular	8	Print
Red	11214 Axle Pin 3L with Friction Ridges Lengthwise and 1L Axle	7	Print
Dark Bluish Gray	22961 Pin Connector Hub with 1 Axle	7	Print
Dark Bluish Gray	10928 Gear 8 Tooth [Reinforced]	6	Print
Light Bluish Gray	32054 Pin Long with Friction Ridges Lengthwise and Stop Bush [3 Lateral Holes, Big Pin Hole]	6	Print
Red	32062 Axle 2 Notched	6	Print
Yellow	32140 Beam 2 x 4 L-Shape Thick	6	Print
Black	32250 Beam 3 x 5 L-Shape with Quarter Ellipse Thin	6	Print
Dark Bluish Gray	32278 Beam 1 x 15 Thick	6	Print
Black	3705 Axle 4	6	Print
Black	18654 Pin Connector Round 1L [Beam]	5	Print
Yellow	32123b Bush 1/2 Smooth with Axle Hole Semi-Reduced	5	Print
Light Bluish Gray	32184 Axle and Pin Connector Perpendicular 3L with Centre Pin Hole	5	Print
Black	32316 Beam 1 x 5 Thick	5	Print
Yellow	32523 Beam 1 x 3 Thick	5	Print
Dark Bluish Gray	32525 Beam 1 x 11 Thick	5	Print
Black	32526 Beam 3 x 5 L-Shape Thick	5	Print
Light Bluish Gray	44874 Pin Connector Hub with 2 Pins with Friction Ridges Lengthwise [Small Squared Pin Holes]	5	Print
Yellow	65487 Pin Connector Hub with 1 Pin with Friction Ridges Lengthwise [Centered Friction Ridge]	5	Print
Yellow	15068 Brick Curved 2 x 2 x 2/3	4	Print
Black	2412b Tile Special 1 x 2 Grille with Bottom Groove	4	Print
Tan	32002 Pin 3/4	4	Print
Yellow	32063 Beam 1 x 6 Thin	4	Print
Black	32271 Beam 1 x 9 Bent (7 - 3) Thick	4	Print
Yellow	32524 Beam 1 x 7 Thick	4	Print
Tan	39888 Pin Long without Friction Ridges, with Anti-Roll Notch	4	Print
Black	40490 Beam 1 x 9 Thick	4	Print
Light Bluish Gray	41678 Axle and Pin Connector Perpendicular Double Split	4	Print
Red	59900 Cone 1 x 1 [Top Groove]	4	Print
Black	61409 Brick Sloped 18° 2 x 1 x 2/3 with 4 Slots / Grate	4	Print
White	6141 Plate Round 1 x 1 with Solid Stud	4	Print
Light Bluish Gray	61903 Universal Joint 3L [Complete Assembly]	4	Print
Black	62462 Pin Connector Round [Slotted]	4	Print
Light Bluish Gray	63869 Axle and Pin Connector Perpendicular Triple	4	Print
Red	65304 Pin Long with Friction Ridges Lengthwise and Stop Bush [2 Lateral Holes, Small Pin Hole]	4	Print
Yellow	71708 Beam 2 x 3 L-Shape with Quarter Ellipse Thick	4	Print
Red	87580 Plate Special 2 x 2 with Groove and Center Stud (Jumper)	4	Print
Light Bluish Gray	94925 Gear 16 Tooth Reinforced [New Style]	4	Print
Black	99773 Beam Triangle Thin [Type II]	4	Print
Yellow	24116 Panel Curved and Bent 6 x 3	3	Print
Black	32014 Axle and Pin Connector Angled #6 - 90°	3	Print
Black	32034 Axle and Pin Connector Angled #2 - 180°	3	Print
Black	32270 Gear 12 Tooth Double Bevel	3	Print
Yellow	32526 Beam 3 x 5 L-Shape Thick	3	Print
Black	39793 Connector Beam 3 x 3	3	Print
Light Bluish Gray	42195 Driving Ring Connector Smooth [2 rounded and 2 flat side walls]	3	Print
Black	11478 Beam 1 x 5 Thin with Axle Holes on Ends	2	Print
Black	18677 Plate Special 1 x 2 with Pin Hole Underneath	2	Print
Light Bluish Gray	3069b Tile 1 x 2 with Groove	2	Print
Red	3070b Tile 1 x 1 with Groove	2	Print
Yellow	32009 Beam 1 x 11.5 Double Bent Thick	2	Print
Black	32126 Axle and Pin Connector Toggle Joint Smooth	2	Print
Black	32140 Beam 2 x 4 L-Shape Thick	2	Print
Black	32523 Beam 1 x 3 Thick	2	Print
Yellow	32525 Beam 1 x 11 Thick	2	Print
Tan	3749 Axle Pin without Friction Ridges Lengthwise	2	Print
Yellow	44809 Pin Connector Perpendicular 2 x 2 Bent	2	Print
Black	63869 Axle and Pin Connector Perpendicular Triple	2	Print
Yellow	6632 Beam 1 x 3 Thin	2	Print
Black	71708 Beam 2 x 3 L-Shape with Quarter Ellipse Thick	2	Print
Dark Bluish Gray	87083 Axle 4 with Stop	2	Print
Light Bluish Gray	92693 Linear Actuator Mini with Dark Bluish Gray Head and Orange Axle	2	Print
Red	11477 Brick Curved 2 x 1 No Studs [1/2 Bow]	1	Print
Yellow	11947 Panel Fairing #22 5L Small Smooth, Side A	1	Print
Black	15573 Plate Special 1 x 2 with 1 Stud with Groove and Inside Stud Holder (Jumper)	1	Print
Tan	18575 Gear 20 Tooth Double Bevel with Axle Hole Type 1 [+ Opening]	1	Print
Light Bluish Gray	18654 Pin Connector Round 1L [Beam]	1	Print
Black	18938 Turntable Large Type 3 Top, 60 Tooth	1	Print
Light Bluish Gray	18939 Turntable Large Type 3 Base	1	Print
Dark Bluish Gray	24120 Digger Bucket 4 x 7	1	Print
Dark Bluish Gray	27940 Pin Connector Hub with 2 Axles	1	Print
Black	3022 Plate 2 x 2	1	Print
Yellow	3023 Plate 1 x 2	1	Print
Yellow	3032 Plate 4 x 6	1	Print
Black	32000 Brick 1 x 2 [2 Pin Holes]	1	Print
Black	32013 Axle and Pin Connector Angled #1	1	Print
Light Bluish Gray	32073 Axle 5	1	Print
Black	32184 Axle and Pin Connector Perpendicular 3L with Centre Pin Hole	1	Print
Tan	32198 Gear 20 Tooth Bevel	1	Print
Dark Bluish Gray	32524 Beam 1 x 7 Thick	1	Print
Red	3623 Plate 1 x 3	1	Print
Red	3706 Axle 6	1	Print
Yellow	3710 Plate 1 x 4	1	Print
Light Bluish Gray	3713 Bush	1	Print
White	40490 Beam 1 x 9 Thick	1	Print
Yellow	44294 Axle 7	1	Print
Black	44567b Hinge Plate 1 x 2 Locking with 1 Finger on Side, without Groove	1	Print
Red	47905 Brick Special 1 x 1 with Studs on 2 Sides	1	Print
Black	54200 Brick Sloped 30° 1 x 1 x 2/3 (Cheese Slope)	1	Print
Black	57360 Hinge Cylinder 1 x 2 Locking with 2 Click Fingers and Axle Hole, 7 Teeth	1	Print
Dark Bluish Gray	59426 Axle 5.5 with Stop [Rounded Short End]	1	Print
Yellow	59443 Axle Connector Smooth [with x Hole + Orientation]	1	Print
Light Bluish Gray	60485 Axle 9	1	Print
Dark Bluish Gray	61904 Axle and Pin Connector Block 4 x 3 x 2 1/2 [Linear Actuator Holder]	1	Print
Yellow	64391 Panel Fairing # 4 Small Smooth Long, Side B	1	Print
Yellow	64683 Panel Fairing # 3 Small Smooth Long, Side A	1	Print
Light Bluish Gray	65489 Pin Connector Hub Perpendicular 3L with 4 Pins (Squared Holes)	1	Print
Tan	6589 Gear 12 Tooth Bevel	1	Print
Yellow	87079 Tile 2 x 4 with Groove	1	Print
Light Bluish Gray	92907 Axle and Pin Connector Perpendicular Split	1	Print
Light Bluish Gray	98138 Tile Round 1 x 1	1	Print
Black	15379 Link Tread with Beveled Edge	4 spare	Print
Light Bluish Gray	4274 Pin 1/2 without Friction Ridges	2 spare	Print
Black	61332 Pin with Friction Ridges Lengthwise with No Center Slots	2 spare	Print
Light Bluish Gray	18654 Pin Connector Round 1L [Beam]	1 spare	Print
Black	18654 Pin Connector Round 1L [Beam]	1 spare	Print
Red	3070b Tile 1 x 1 with Groove	1 spare	Print
Tan	32002 Pin 3/4	1 spare	Print
Yellow	32123b Bush 1/2 Smooth with Axle Hole Semi-Reduced	1 spare	Print
Light Bluish Gray	3713 Bush	1 spare	Print
Black	54200 Brick Sloped 30° 1 x 1 x 2/3 (Cheese Slope)	1 spare	Print
White	6141 Plate Round 1 x 1 with Solid Stud	1 spare	Print
Light Bluish Gray	98138 Tile Round 1 x 1	1 spare	Print
Light Bluish Gray	60849 Equipment Hose Nozzle / Gun with Side String Hole Simplified	2	Buy
Trans-Clear	98138 Tile Round 1 x 1	2	Buy
Trans-Clear	24116 Panel Curved and Bent 6 x 3	1	Buy
Trans-Orange	58176 Light Cover 1 x 1 Round with Internal Bar / Barraki Eye	1	Buy
[No Color/Any Color]	72184 Sticker Sheet for Set 42121-1	1	Buy
Trans-Orange	58176 Light Cover 1 x 1 Round with Internal Bar / Barraki Eye	1 spare	Buy
Light Bluish Gray	60849 Equipment Hose Nozzle / Gun with Side String Hole Simplified	1 spare	Buy
Trans-Clear	98138 Tile Round 1 x 1	1 spare	Buy

Print set 42121 at home

The set tool makes an STL file for each of the 562 printable pieces, sorted by colour, plus a shopping list for the 7 to buy. Free, no account, and it runs on your own phone or computer.

Get the free print files

Pro 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.