01
Joint housings that bind after anodizing
Bearing bores machined to nominal, then anodized, then the bearing will not seat. The coating adds several microns. We cut bore pre-plate and control the finish so the press fit stays in spec.
Robotics & Automation
Precision Robot Parts, CNC Machined
GreatLight machines robot parts — joint housings, arm links, wrist flanges, base plates — on 16 simultaneous 5-axis centers. Tolerances to ±0.005 mm, from a single prototype to 10,000+ part runs.
±0.005 mm tolerance16 five-axis centersNo MOQISO 9001:201512-hour quote3–5 day shipping
±0.005 mmAchievable tolerance
16Simultaneous 5-axis centers
127High-precision CNC machines
99.99%Qualification rate
Common Problems
Where robot parts usually go wrong
These are the failure modes we see most often when a robotics team sends a new design to a shop.
02
Arm links that flex under load
A linkage that looks fine on a drawing deflects at full reach. Thin walls, sharp internal corners, no rib. We flag the stiffness problem at DFM and suggest a geometry change before the first cut.
03
Axis alignment drift across a sub-assembly
Each part passes inspection. Bolted together, the axes do not line up. Datum choices and hole-to-hole position matter more than any single dimension. We control position, not just size.
04
A good prototype that cannot be produced
The prototype runs on one machine with hand work. At 500 units the process does not scale. We plan the prototype around the production process from the first quote.
How We Build Robot Parts
One shop for the joint, the link and the frame
5-axis milling, turning and inspection under one roof — so the datum stays the same from raw stock to finished part.
Joint Geometry
5-axis cutting for joints and wrist housings
A robot joint is mostly a set of related bores and faces. Bearing seats, motor pilot, encoder mount, cable passage. If they are cut in separate setups, the stack-up shows up as backlash or a stiff axis.
Our 16 simultaneous 5-axis centers cut the bearing bore, the perpendicular mounting face and the bolt pattern in one setup. That removes the re-fixturing error. A Ø400 mm rotary table handles larger joint bodies without repositioning.
- 1Bearing seats in one setupBore, face and bolt circle held to a single datum.
- 2Thin-wall joint bodiesLight finishing passes and low clamping force to avoid distortion.
- 3Hard and light materials7075, 6061-T6, TC4 (Ti-6Al-4V), 17-4PH, carbon fibre.
Structure & Frame
Arm links, base plates and mounting flanges
Structural robot parts are about stiffness per gram. You want the lightest link that still holds position when the arm is extended and the payload is at full reach.
We machine arm segments, adapter plates, base frames and end-effector flanges from aluminum and titanium billet. Pocketing, ribbing and wall thickness are decided together with you at DFM, not after the part is cut.
Long parts are not a problem. Our largest travel is 4,000 × 400 × 150 mm, so a single-piece arm rail does not need to be spliced.
- 1Up to 4,000 mmMaximum processing size for long rails and frames.
- 2Motor integration featuresPilot bores, keyways, dowel holes, tapped patterns.
- 3Prototype to 10,000+Same process scales from one part to a production run.
Part Families
Which process fits which robot part
A rough guide. The final call depends on geometry, quantity and tolerance.
| Part | Process | Why |
|---|---|---|
| Joint housing | 5-axis milling | Multiple bores and faces, one datum |
| Wrist flange | 5-axis + turning | Round body with bolt pattern |
| Arm link | 3 or 4-axis milling | Long part, features on few faces |
| Motor shaft adapter | CNC turning | Concentric diameters, tight runout |
| Base plate | 3-axis milling | Flat part, hole pattern, pockets |
| Prototype shell | 5-axis / vacuum casting | Thin walls, low quantity first |
| End-effector bracket | Mill-turn | Turning plus cross features |
| Large arm rail | 5-axis, 4,000 mm travel | One piece, no splice joint |
Services
What we do for robotics teams
Six services cover most robot part programs. All run in-house.
01
5-Axis CNC Machining
Complex joints and housings cut in one setup. 16 simultaneous 5-axis centers.
02
CNC Milling & Turning
Shafts, adapters, inserts and mill-turn parts with tight concentricity.
03
Rapid Prototyping
Functional metal and plastic prototypes before you commit to tooling.
04
Surface Finishing
Anodizing, plating, bead blasting, laser marking. Bore compensation handled.
05
Sheet Metal Fabrication
Covers, brackets and enclosures that pair with machined structural parts.
06
Vacuum Casting & 3D Printing
Small-batch covers and shells when quantity is low and geometry is complex.
Capability
Machine and tolerance range
Numbers you can check a drawing against before you send it.
| Item | Range | Note |
|---|---|---|
| Tolerance | ±0.005 mm | ±0.0002 in on critical features |
| Fine finish | Ra 0.2–0.8 μm | Bearing seats and sealing faces |
| Standard finish | Ra 0.8–1.6 μm | General machined surfaces |
| As-machined | Ra 1.6–3.2 μm | Non-critical faces |
| 5-axis centers | 16 | Simultaneous, 5 sides per setup |
| Largest travel | 4,000 × 400 × 150 mm | Long rails and frames |
| Rotary table | Ø400 mm | Large joint bodies |
| Materials | Aluminum, stainless, steel, titanium, plastic | 6061-T6, 7075, TC4, 17-4PH, PEEK |
Why GreatLight
What you get that a general shop does not offer
15Y
Machining since 2011
15 years of precision work, 3 wholly-owned plants, 7,600 m² of floor.
±0.005
Tolerance held in production
Not just on a first article. In-process monitoring on every run.
12h
Quote and DFM in 12 hours
You get a manufacturability read before you place the order.
24h
Production starts in 24 hours
Material on the floor and programs ready once drawings are released.
0
No minimum order quantity
One prototype or 10,000+ parts. Same process, same inspection.
100%
Inspection before shipment
Raw material check, in-process monitoring, final inspection.
127CNC machines total
150Technicians
7,600 m²Manufacturing space
<2%Historical late-delivery rate
Applications
Robot part families we machine
Arm and joint assemblies
Joint housings, links and wrist flanges for multi-axis arms.
- ±0.005 mm
- 5-axis
- 6061-T6 / 7075
Humanoid structural parts
Lightweight shells, frames and adapter plates.
- Thin-wall
- Ra 0.8–1.6 μm
- Anodized
Drive and transmission parts
Shaft adapters, inserts and gearbox mounting plates.
- Turning
- Concentric
- 17-4PH / TC4
End-effector and tooling
Brackets and mounts that bolt to a wrist flange.
- Mill-turn
- Bolt pattern
- No MOQ
FAQs
Questions robotics engineers ask us
What tolerance can you actually hold on a robot joint housing?
We quote ±0.005 mm on critical features such as bearing bores and mating faces. That is not a shop-wide default for every dimension.
Non-critical faces are usually held at ±0.05 mm, which keeps the part affordable. Tell us which features carry the axis alignment and we will put the tight tolerance there.
Can you machine a one-off prototype and then scale it to production?
Yes. There is no minimum order quantity. We run one part or 10,000+ parts.
The point is to plan the prototype around the production process. If the prototype is cut with a method that does not scale, you will pay for a second process later.
How do you handle anodizing on a bearing bore?
Hardcoat and clear anodizing add coating thickness, typically a few microns per surface. A bore cut to nominal will be undersized after coating.
We cut the bore to a pre-plate dimension that accounts for the coating, and we mask bores that must stay conductive. Tell us the final fit and the coating type at quoting.
Which materials do you recommend for a lightweight arm link?
6061-T6 is the usual choice for a general arm link. It machines well and anodizes cleanly.
7075 gives higher strength for the same wall thickness, but it costs more and is less weldable. TC4 (Ti-6Al-4V) is for high-load joints where weight matters most. We will flag the trade-off at DFM.
Can you machine a single-piece arm rail instead of splicing it?
Our largest travel is 4,000 × 400 × 150 mm, so a long rail can be cut as one part.
A single piece removes the splice joint, which is often where stiffness and alignment are lost. Send the length and we will confirm it fits the travel.
What inspection data comes with the parts?
Every order gets raw material check, in-process monitoring and final inspection before shipment. Inspection reports are available on request.
If a drawing has a critical feature, we will record the measured value for it. Ask for the report at quoting so it is scheduled into the run.
How fast can you quote and ship a robot part order?
Quotation and free DFM analysis come back within 12 hours. Production can start within 24 hours after drawings are released.
Standard parts ship in 3–5 days. Quantities and finishing add time, and we will state that in the quote rather than after the order.
Do you sign an NDA for robot designs?
Yes. Uploads are secure and confidential, and we sign an NDA on request.
Robot designs often carry real IP in the joint geometry. We treat drawings and CAD files as confidential by default.
Send your robot part drawings
Upload a STEP file and we will return a quote with a DFM read within 12 hours. One prototype or 10,000+ parts.
12-hour quoteNo MOQ100% inspectionNDA on request
