Bugatti Tourbillon Supercar Uses a 3D Printed Chassis

The Bugatti Tourbillon supercar uses an additively manufactured structural element as the center of its chassis concept. That is the part worth studying. A printed chassis is not a printed car. The structure carries load, and everything bolted to it was made another way.

Why print it at all? A conventional monocoque is limited by what a mold and a press can reach. Printing removes that limit. Ribs can follow the actual load path instead of a straight line. Wall thickness can change along a single piece. Two brackets that would need four fasteners can become one continuous geometry.

The trade is not free. Layer-by-layer build leaves anisotropy: strength along the build direction differs from strength across it. Surface finish as-built sits far coarser than a machined face. So the printed section handles shape and stiffness, while the machined section handles fit.

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  Printed structureLoad paths, hollow sections, integrated ribs
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  Machined interfacesBearing bores, mounting faces, threaded holes
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  Bonded jointsAdhesive or fastener lines between the two

Every additive process leaves a tolerance stack that a bearing or a suspension pickup point cannot absorb. Metal powder bed fusion typically holds a few tenths of a millimeter on as-built features. That is fine for a rib, useless for a Ø40 mm bearing seat that must sit within ±0.005 mm.

The usual answer is near-net printing followed by CNC finishing. Print the blank oversized by 0.3 to 0.8 mm on critical faces, then machine them back to drawing. This keeps the internal channels and hollow cores that only printing can make, while the datums, bores and sealing faces come off a 5-axis machine.

Our shop does this daily on automotive and aerospace parts. Sixteen simultaneous 5-axis machining centers handle the finishing passes, and a Ø400 mm rotary table lets us reach five sides of a printed blank without re-fixturing. Re-fixturing is where position error creeps in, so we avoid it when the part allows.

One more thing engineers ask about: heat. Printing leaves residual stress. If a printed blank is machined before stress relief, the part can move after the last pass and the bore goes oval. Plan the stress relief step before finish machining, not after.

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  As-built printed feature±0.2–0.4 mm typical
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  Machined critical face±0.005 mm achievable
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  Stress reliefBefore finish passes, not after

Printing wins when geometry is complex, count is low, and the part carries stiffness rather than sliding contact. Chassis nodes, suspension arms, brackets with internal channels, and heat-exchanger cores all fall into that group. If the design has ten features that a mold cannot pull, printing is likely cheaper than re-designing for casting.

Machining wins when the part needs a tight bore, a flat sealing face, a thread, or a wear surface. It also wins on simple geometry at volume. A solid aluminium bracket with three holes does not need a printer; it needs a 3-axis mill and a good fixture. Running a 10,000 piece order through a printer is slow and expensive.

The middle ground is the interesting one. Print the hard geometry, machine the functional faces, and finish the rest. For aluminium 6061-T6, 7075 or Ti-6Al-4V printed blanks, we machine to Ra 0.8–1.6 μm on sealing faces and Ra 0.2–0.8 μm where a bearing runs. Anodizing, hardcoat or bead blasting follow if the part needs wear or corrosion protection.

Do not print a part that only needs to be milled. We see this often: a designer sends a solid block for printing when a 4-axis mill would make it in one setup for less. Send the drawing and we will say which route fits.

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  Choose printingComplex internal geometry, low volume, stiffness-driven
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  Choose CNCTight bores, wear faces, simple geometry at volume
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  Choose bothNear-net printed blank plus machined interfaces

Material selection usually decides the process before geometry does. Aluminium 6061-T6 and 7075 machine well and print with moderate difficulty. Titanium Ti-6Al-4V prints well and machines slowly, but its strength-to-weight ratio justifies the cycle time on suspension uprights and brackets.

Steel grades 4130, 4140 and 4340 remain the default for high-load machined links and hubs. They are rarely printed. Stainless 17-4PH bridges both worlds: printable in powder bed systems and machinable to tight tolerances after a heat treat cycle.

For non-structural covers, ducting and interior brackets, plastics are often enough. ABS, PC, POM and PA cover most prototype work. PEEK and carbon fibre reinforced grades appear when temperature or stiffness demands it, though both raise cost and reduce machinability.

We stock and machine all of these. If you are weighing a printed titanium node against a machined 7075 one, the deciding number is usually stiffness per gram against cost per part, not raw strength.

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  Aluminium6061-T6, 7075, 6082, ADC12
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  TitaniumTA1, TA2, TC4 (Ti-6Al-4V)
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  Stainless17-4PH (SUS630), 316L, 303
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  PlasticsABS, PC, POM, PA, PEEK, carbon fibre