01
The print looks fine, then the thread strips
SLA resin taps badly and SLS nylon holds a thread only in thick walls. If the part needs M3 threads under load, printing is the wrong call. We machine those features instead.
Additive Manufacturing
3D Printing Technology
We print prototypes in SLA, SLS and metal, then machine the same geometry on 127 CNC machines when the design locks. One supplier from first sample to 10,000-part runs.
SLA / SLS / SLM±0.005 mm CNC toleranceNo minimum order12-hour quoteISO 9001 · IATF 16949NDA on request
2011Printing and machining since
127High-precision CNC machines
±0.005 mmTolerance on machined parts
3–5 daysTypical part shipment
Where it goes wrong
Four Problems Engineers Bring Us
Most 3D printing complaints come from picking the process before the geometry.
02
Layer lines ruin a sealing face
As-printed surfaces sit around Ra 8–16 μm with visible stair-stepping. A gasket face or O-ring groove printed flat will leak. Plan a machined face or a post-finish step.
03
The prototype passes, the production part does not
A resin model can pass a fit check and still fail in service, because the printed material is not the material you will ship. Test on the real alloy.
04
Nobody can quote it because the CAD is not watertight
Open shells and zero-thickness walls stall a quote for days. One DFM pass before printing saves a rebuild.
Our approach
Print for Speed, Machine for Reality
We treat 3D printing technology as a step in the route, not the whole route.
Step one
Printed Prototypes in Days, Not Weeks
3D printing is additive: a head or laser lays down material layer by layer from a CAD file, so there is no mold and no block of stock to remove. Setup cost is close to zero, which is why the first unit is cheap and the thousandth unit is not.
We use it where it wins. SLA gives a smooth surface for form-and-fit checks and clear parts. SLS builds tough nylon parts with living hinges and snap fits, and it handles internal channels that a cutter cannot reach. Metal printing suits lattice and conformal-cooling geometry that would need many setups on a mill.
- 1Form and fitSLA or SLS within days of a frozen CAD file
- 2Complex internal geometryChannels and lattices a cutter cannot reach
- 3No toolingDesign changes cost nothing until you cut metal
Step two
When to Stop Printing and Cut Metal
Printed parts are anisotropic. SLS nylon is weaker across the layer direction than along it, and resin creeps under sustained load. Anything that carries a load, seals a fluid, or takes a thread insert usually belongs on a CNC machine.
That switch is where we add the most value. The same shop that printed your sample machines the production part to ±0.005 mm with finishes from Ra 0.2–0.8 μm, so tolerances and datums do not get renegotiated between two vendors. We quote both routes side by side and tell you which one the geometry actually needs.
- 1Load-bearing featuresMachined threads, bores and bearing seats
- 2Sealing surfacesGround or milled faces at Ra 0.8–1.6 μm
- 3Tight tolerances±0.005 mm on critical dimensions
Selection guide
Which Process Fits the Part
Use this as a first filter. Geometry and load decide, not the price sheet.
| Requirement | 3D printing | CNC machining |
|---|---|---|
| Surface finish | Ra 8–16 μm as built | Ra 0.2–3.2 μm |
| Tolerance | ±0.1 mm typical | ±0.005 mm |
| Wall thickness | 0.8 mm and up | 0.5 mm and up, rigid |
| Best batch size | 1 to 50 units | 1 to 10,000+ units |
| Threads | Inserts or coarse only | Cut threads, all sizes |
| Material choice | Resin, nylon, metal powder | 40+ alloys and plastics |
| Lead time | 3–5 days | 3–5 days after DFM |
| Design changes | Free until you cut | New program per revision |
Services
What We Run In-House
01
Custom 3D Printing
SLA, SLS and metal printing for prototypes, jigs and low-volume functional parts, quoted from your STEP or STL file.
02
Rapid Prototyping
Printed or machined samples in days so a design review happens on a real part, not a screen.
03
5 Axis CNC Machining
16 simultaneous 5-axis centers for contoured surfaces, deep pockets and single-setup datums.
04
CNC Milling & Turning
27 three-axis machines, 12 four-axis mills and 16 mill-turn centers up to 4,000 mm.
05
Vacuum Casting
Urethane copies from a printed master when you need 20 to 50 look-and-feel units in production resin.
06
Part Surface Finishing
Anodizing, plating, powder coating, bead blasting and laser marking on printed and machined parts.
Capabilities
Printing and Machining Scope
| Item | Range | Notes |
|---|---|---|
| Maximum part size | 4,000 mm | Larger parts split and joined |
| Machining tolerance | ±0.005 mm | ±0.0002 in |
| Fine finish | Ra 0.2–0.8 μm | Polished and lapped faces |
| Standard finish | Ra 1.6–3.2 μm | As machined |
| Materials | 40+ grades | Aluminium, stainless, titanium, PEEK, nylon |
| Order quantity | 1 to 10,000+ | No minimum order quantity |
| Inspection | 100% before shipment | Reports on request |
| Certifications | ISO 9001, IATF 16949, ISO 13485, ISO 27001 | Audited annually |
Why GreatLight
Six Reasons Engineers Keep Sending Files
±0.005
Machined tolerance held
Critical dimensions verified against the drawing, with inspection reports available on request.
12 h
Quote and DFM back
You get a price, a lead time and a DFM note on wall thickness or tool reach within 12 hours.
24 h
Production start
Once the drawing is released and material is confirmed, machining can begin the next working day.
99.99%
Qualification rate
Raw material check, in-process monitoring and final inspection on every order.
40+
Materials in stock
6061-T6, 316L, 17-4PH, TC4, Inconel, PEEK and carbon fibre among the standard list.
NDA
Confidential by default
Uploads stay private, and a signed non-disclosure agreement is available on request.
15 yearsSince 2011
7,600 m²Manufacturing space
3Wholly-owned plants
150Technicians
In the field
Where Printed Samples Lead to Machined Parts
Robotics
Printed joint housings for motion checks, then machined aluminium links for the build.
- 5-axis
- ±0.005 mm
Automotive & EV
Bracket prototypes in SLS nylon, production parts in 6061-T6 with IATF 16949 process control.
- IATF 16949
- Ra 0.8–1.6 μm
Medical Devices
Printed fixtures for trial fits, machined 316L parts with full traceability.
- ISO 13485
- 316L
Electronics
Printed enclosures for board fit, then milled and anodized housings for the pilot run.
- Anodizing
- Pilot run
FAQs
Questions We Get About 3D Printing
How does 3D printing technology actually build a part?
A slicer cuts the CAD model into layers, usually 0.05–0.2 mm thick, and writes a toolpath for each one. The machine then stacks and fuses those layers, either by curing resin with a laser, sintering powder, or melting filament and metal powder.
Because material is added instead of removed, internal channels, lattices and undercuts that would need several CNC setups come out in one build. The trade-off is surface finish and material properties across the layer direction.
What tolerance can I expect from a printed part?
±0.1 mm on a well-oriented SLA or SLS part is realistic, and ±0.3 mm on long thin sections where shrinkage and warping pull the geometry. Metal printing lands in a similar band after support removal.
If the drawing calls for ±0.005 mm, printing will not hold it. We print the sample and machine the feature, or machine the whole part.
Which parts should never be printed?
Anything that seals a fluid, carries a sustained load, or needs a fine thread. Layer lines give a leak path, printed threads strip under torque, and resin creeps over time.
Bearing bores, hydraulic faces and press fits also belong on a mill or lathe. We flag these in the DFM note before you commit to a process.
Do you print in metal?
Yes, in powder-bed metal for lattice and conformal-cooling geometry. We also machine the same alloys, so a printed prototype in TC4 or 17-4PH can be followed by a machined production part in the same grade.
Tell us the load case and we will say whether printing or machining is the better route.
Can I move a printed prototype straight to production without changes?
The geometry usually survives; the material and tolerances do not. A printed part is isotropic in the build plane only, and its surface is rougher than a machined face.
In practice we keep the design intent, adjust wall thickness and add machining allowance on critical faces, then cut the production part to ±0.005 mm.
What files do you need for a quote?
A STEP file for machining and an STL or 3MF for printing, plus a 2D drawing if any dimension is toleranced. Note the critical faces and the finish.
We return a price, a lead time and a DFM analysis within 12 hours. Files stay confidential, and an NDA is available on request.
How many units before CNC becomes cheaper?
It depends on part size and feature count, but printing usually stops paying above roughly 50 units, once per-part machine time and setup dominate the cost.
We quote both routes on the same RFQ so you can see the crossover point for your geometry instead of guessing.
Do you handle finishing after printing?
Yes. Printed and machined parts both go through the same finishing line: anodizing, plating, powder coating, bead blasting, polishing and laser marking.
Laser marking needs a minimum character height of 1.5 mm. Ask for it on the drawing so the marking sits on a flat face.
Send a File, Get a Route and a Price
Upload your CAD and we will come back with a process recommendation, a quote and a DFM note within 12 hours.
12-hour quote100% inspectionNo minimum orderNDA on request
