01
A sealing face that weeps
As-built SLM surfaces carry Ra 8–12 μm and partly bonded powder. Bolt it against a gasket and it leaks at 2 bar. The mating face needs to be cut, not printed.
3D Printing and Machining
Auto Parts 3D Printing
Print the geometry first, then cut the critical faces. We run SLM metal and SLA/SLS plastic for auto parts 3D printing, and finish sealing faces, bores and threads on 127 CNC machines to ±0.005 mm.
SLM metal printingSLA and SLS plastics±0.005 mm finishingIATF 16949:2016No MOQNDA on request
±0.005 mmAchievable tolerance after finishing
127High-precision CNC machines
12 hQuote and free DFM analysis
3–5 daysTypical shipping window
Where printed auto parts fail
Why a Printed Auto Part Can Still Be Rejected
Printing gets the shape. These four problems show up at test fit, at pressure check, or on the dyno.
02
A bore that will not hold a bearing
Print tolerance is usually ±0.1 mm on a good day. Press a bearing into that and the fit is either loose in the housing or cracked during installation.
03
A thread that strips on the second torque
Printed threads in aluminum or nylon shear at the root. A 3D printed bracket is fine for a cable clip, not for an M8 mount pulled to 25 N·m.
04
A quote that hides the finishing step
The print price looks low, then the sealing face, bearing bore and thread inserts get quoted separately. The real cost only appears after two rounds of RFQs.
How we build printed auto parts
Print Near-Net, Machine the Faces That Matter
One shop handles both steps, so the print and the cut are planned together instead of arguing over who missed the tolerance.
Step 1
SLM Metal Printing for Functional Auto Parts
For parts that see heat, pressure or vibration, we print in metal by SLM. Titanium TA1, TA2 or TC4 (Ti-6Al-4V), Inconel and 17-4PH stainless cover most brackets, manifolds, heat shields and lightweight housings. Aluminum grades such as 6061 and 7075 can also be printed, though for a flat plate a machined blank is still cheaper.
Print orientation decides the outcome. A housing printed flat has different layer lines at the flange than one printed upright, and the layer direction sets the fatigue path. We set orientation so that load goes along the layers, not across them, then machine the sealing face, bearing bores and threads.
- 1Wall thickness from 0.8 mmThin shells print cleanly; below that, expect porosity and rework.
- 2Build size to 250 mm classLarger parts get split and joined, or move to CNC.
- 3Support removal by handInternal channels need drain paths, or supports stay trapped.
Step 2
SLA and SLS Plastic Prototypes for Fit and Form
Plastic covers the early rounds. SLA in ABS-like resin and SLS in PA or glass-filled nylon give you a part in your hand weeks before tooling. Use them for connector housings, ducting, clips, covers and dash parts where the question is fit and shape, not strength.
Plastic auto parts have a short list of failure modes: creep under a constant load, UV fading, and heat softening near an engine bay. We call those out in the DFM note before printing, so the material choice matches where the part actually sits. Carbon fibre reinforced nylon is the usual pick when a clip needs stiffness.
- 1Tolerance ±0.1 mmEnough for fit checks, not for a press fit.
- 2Ra 1.6–3.2 μm as-printedFine for covers; polish if the surface is visible.
- 3Hand finishing availableSanding, primer and paint on request.
Choosing a process
Printed, Machined, or Printed Then Machined?
Use this to pick the route before you request a quote.
| Route | Best for | Limits |
|---|---|---|
| SLA resin print | Fit checks, covers, interior trim | Not for load or heat |
| SLS nylon print | Clips, ducts, brackets under light load | Creeps under constant load |
| SLM metal print | Complex organic shapes, low volume | Needs bore and face finishing |
| SLM plus CNC | Functional prototypes, small runs | Highest cost per part |
| 5-axis CNC from billet | Flanges, manifolds, suspension links | Tool access limits deep pockets |
What we run
Services Behind Printed Auto Parts
Printing is one step. These are the rest of the shop, so a part does not leave here half finished.
01
Custom 3D Printing
SLM metal, SLA resin and SLS nylon. Orientation, supports and heat treatment planned before the build.
02
5 Axis CNC Machining
16 simultaneous 5-axis centers cut sealing faces, bearing bores and threads on printed blanks.
03
CNC Milling and Turning
16 mill-turn centers handle shaft and housing features in one setup, so concentricity holds.
04
Rapid Prototyping
From one prototype to a 10,000+ part run. No minimum order quantity at either end.
05
Metal Die Casting
ADC12 and aluminum castings once the printed design is frozen and volume justifies tooling.
06
Part Surface Finishing
Anodizing, electroless nickel, bead blasting, black oxide and laser marking down to 1.5 mm characters.
Scope
Printed and Machined Auto Part Scope
Numbers we work to every day.
| Item | Capability | Note |
|---|---|---|
| Achievable tolerance | ±0.005 mm | On machined features |
| Fine finish | Ra 0.2–0.8 μm | Bores and sealing faces |
| High finish | Ra 0.8–1.6 μm | General mating surfaces |
| Maximum part size | 4,000 mm | Largest machine travel |
| Materials | Aluminum, stainless, steel, titanium, plastics | Full list on the quote page |
| Inspection | 100% before shipment | Reports on request |
Why GreatLight
Fifteen Years of Cutting Metal After Printing It
Six things that decide whether a printed auto part ships or sits in a rework bin.
2011
In business since 2011
15 years of prototype and low-volume auto work across 3 wholly-owned plants and 7,600 m² of floor space.
±0.005 mm
Tolerance we hold
Machined features reach ±0.005 mm, so a printed housing can carry a press-fit bearing.
99.99%
Qualification rate
Raw material check, in-process monitoring and final inspection on every order.
16
Simultaneous 5-axis centers
Complex printed blanks get cut in one setup, which keeps datums consistent.
12 h
Quote turnaround
Quotation and free DFM analysis within 12 hours. Production can start within 24 hours.
<2%
Historical late-delivery rate
Parts ship in 3–5 days on the standard route, and we track the exceptions.
IATF 16949:2016Automotive quality system
ISO 9001:2015Quality management
ISO 27001:2022Data and file security
150Technicians on staff
Printed auto parts in the field
What These Industries Require, and What We Deliver
Engine and powertrain
Printed intake and bracket shapes, then sealing faces and bolt holes cut flat.
- Ra 0.8–1.6 μm
- ±0.005 mm
- 3–5 days
EV and battery hardware
Busbar covers and mounting frames printed for fit, then machined at the contact faces.
- No MOQ
- 100% inspection
- 12 h quote
Suspension and chassis
Load paths run along the print layers; bearing bores and threads are cut afterward.
- IATF 16949:2016
- ±0.005 mm
- 5-axis
Under-hood brackets
Heat and vibration decide the material; we flag creep and softening before printing.
- SLM metal
- SLS nylon
- NDA on request
FAQs
Questions Engineers Ask Before Printing Auto Parts
When is 3D printing the wrong choice for an auto part?
When the part carries a repeating load, sees more than about 120 °C, or has a sealing face. Printed layers are the weak direction, and as-built surfaces leak.
A machined billet part is usually cheaper than a printed one on simple geometry, so printing only pays off when the shape is genuinely complex.
Can a printed part hold a press-fit bearing?
Not as printed. The bore needs to be machined after the build, which is why we keep 5-axis centers next to the printers.
With a machined bore at ±0.005 mm, a printed aluminum housing can take a bearing the same way a billet housing does.
Which metal should I pick for a functional prototype?
Ti-6Al-4V (TC4) for strength at low weight, 17-4PH stainless when corrosion and hardness matter, Inconel for exhaust-side heat.
For a bracket that only needs stiffness, printed aluminum or a machined 6061 blank is the cheaper answer.
How do you handle layer orientation?
We set the build orientation so the main load runs along the layers rather than across them. On a bracket that means printing it upright so the tensile load follows the layer plane.
Where the load direction changes, we thicken the section or move that feature to a machined insert.
What tolerance can I expect on the printed surface?
Around ±0.1 mm on a well-supported SLA or SLS part, and similar on SLM metal before finishing.
Machined features reach ±0.005 mm. Plan your critical dimensions on faces that a cutter can reach.
Do printed auto parts need support removal?
Yes for SLM and SLA. Internal channels need drain paths, or supports stay trapped inside the part.
We review the model during the DFM pass and tell you where a channel will trap material before the build starts.
How fast can I get a printed prototype?
Quotation and free DFM analysis come back within 12 hours, and production can start within 24 hours.
Parts ship in 3–5 days on the standard route. The historical late-delivery probability is below 2%.
What about confidentiality on new vehicle designs?
Uploads are secure and confidential. We hold ISO 27001:2022 for information security.
An NDA is available on request before you send any model file.
Send Your Model, Get a Print and Machining Plan
Upload the CAD file and we come back within 12 hours with a quote and a free DFM analysis covering print orientation, support strategy and which faces need cutting.
12-hour quote100% inspectionNo minimum order quantityNDA on request
