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CNC Machining for Robotics and Automation

Joint housings, gearbox flanges, encoder mounts, robot finger links and end effectors — usually aluminium, usually needed sooner than the schedule allows. Quotes in 16 hours, no minimum order.

CNC machined aluminium robot finger linkages, knuckle joints, pivot blocks and finger bases with black rubber pads – GY Machining
The three we hear most

Problems buyers bring us in this sector

Robotics work is iterative and impatient. These are the three problems that come up most, and how we keep them from slowing you down.

“Revision three is due before revision two has arrived”

Quote in 16 hours. We keep programs and setups per part number, so a revision of a part we have already made sits at the fast end of the 7–15 day window. Give us the previous part number in the RFQ and we will find the file.

“The bearing bore is loose — or the bearing will not go in”

Tell us the fit class, not just the nominal. We work ISO 286 IT6–IT7 on bearing bores and check them with a gauge as well as on the CMM, because a bore that measures right and feels wrong is still wrong.

“Bores on two faces do not line up”

On a four-axis setup the part is not re-clamped between faces, so we hold about 0.01 mm between them. If the geometry forces two setups, you hear about it in the quote, not on the first article.

Typical parts

What we machine for robotics customers

Robotics work is iterative: a part gets made, tested, changed and made again. We quote fast and we keep your programs, so revision two is quicker and cheaper than revision one.

Joint and actuator housings

Milled 6061 and 7075 housings with bearing bores held to an interference or transition fit.

Gearbox and motor flanges

Turned and milled flanges with pilot diameters and bolt circles in true position.

Encoder and sensor mounts

Small precision mounts where concentricity to the shaft decides whether the encoder reads true.

End effectors and grippers

Finger links, knuckles, pivot blocks, finger bases, custom jaws, vacuum plates and tool adapters — usually 6061-T6 or 7075, with press-fit pins and smooth pivot bores.

The parts in the hero are a typical set: three proximal links, three distal links, matching knuckle blocks and pivot pins, machined in one batch and anodised black.

Structural plates and brackets

Mounting plates, links and arms milled from plate, anodised or bead blasted.

Cable and harness hardware

Strain reliefs, clamps and guides — small parts nobody wants to wait three weeks for.

From the shop floor

Robot and quadruped joint housings: four views

These are the parts behind the photos: aluminium joint and actuator housings for robot arms and quadruped robots (robot dogs). Each is machined from solid 6061-T6 or 7075, with the bearing bore, bolt circle and mounting face cut in the same setup where the geometry allows.

CNC machined 6061-T6 aluminium robot joint housing with ribbed lightening pockets, central bearing bore and six-hole bolt circle
Ribbed joint housingRadial pockets remove mass without softening the bearing seat. The ribs carry load from the bolt circle into the central bore.
CNC machined aluminium robot dog joint housing held in hand, showing the tall bearing boss, motor bolt pattern and counterbored flange holes
Bearing boss and output flangeThe output side carries the bearing seat and motor bolt pattern. Boring and turning in one setup keeps the bore and bolt circle concentric.
CNC machined aluminium quadruped robot actuator housing with central bearing boss, eight-hole motor pattern, curved lightening pockets and four mounting ears
Actuator mounting faceEight-hole motor pattern around the bearing boss, curved pockets between the bolt bosses, and four outer ears for the joint axis.
CNC machined aluminium robot dog joint housing with deep ribbed pockets, central bore, bolt circle and asymmetric clearance notch
Pocketed joint housingThe asymmetric notch clears the adjoining link through the joint range of motion; the remaining ribs feed load into the bearing bore.

What we hold on this family

  • Bearing bores to IT6–IT7, with roundness checked on the CMM.
  • Concentricity between bearing bore and motor bolt circle: typically 0.01 mm.
  • Flatness on mounting and sealing faces: typically 0.02 mm.
  • Bolt patterns positionally toleranced to Ø0.05 mm, drilled and reamed in one 4-axis setup where possible.
  • Rib and wall thickness controlled to 1.5–2.5 mm to avoid chatter and distortion.

Typical calls, not a guarantee: send the drawing and we will confirm what the feature needs. See 4-axis milling, aluminium grades, anodising and CMM inspection.

Recent work

Robot dog leg brackets and actuator mounts

The other half of a quadruped robot is the structure around the actuator: the brackets that carry the motor, hold the bearing and connect the joint to the leg. These four are recent parts, machined from 6061-T6 aluminium.

CNC machined aluminium quadruped robot leg saddle bracket with six-hole actuator pad, counterbored ears and curved locating faces
Leg saddle bracketSix-hole actuator pad, counterbored ears and curved locating faces. The saddle locates the leg link; the pad carries the actuator.
CNC machined aluminium robot dog leg joint bracket showing a five-hole saddle face and an eight-hole actuator pattern on the round face
Leg joint bracket – saddle sideFive counterbored holes on the curved face, eight-hole actuator pattern on the round face. Both faces are machined square to each other.
CNC machined aluminium robot dog actuator mount bracket held in hand, showing two bolt circles around a central bore and a relieved body
Actuator mount bracketTwo bolt circles around a central bore, with the body relieved to clear the link. Both patterns share one bore datum.
CNC machined aluminium quadruped robot joint bracket output side with central boss, eight-hole bolt pattern and angled body
Joint bracket – output sideCentral boss, eight-hole pattern and angled body. The circular face and the saddle face are checked for squareness on the CMM.

What these brackets have in common

  • Two or three mounting planes, machined square to each other — typically 0.02 mm.
  • Counterbores for M3–M6 socket-head screws, with the bolt pattern positionally toleranced.
  • A central bore that has to stay concentric with the actuator pattern, usually within 0.01 mm.
  • Relief around the link so the bracket clears through the full range of joint travel.
  • Bead blast, anodising or laser marking on request; 6061-T6 standard, 7075 for higher stiffness.

Send the drawing and the mating parts; we will quote the bracket, the housing and the pin as one set. See CNC machining services, 4-axis milling and get a quote.

Materials and finishes

What these parts are usually made from

6061 for most structure, 7075 where stiffness or strength decides it, POM and nylon where weight or noise does.

What matters on these drawings

What we watch on a robotics drawing

CNC machined 6061-T6 aluminium robot joint housing with a twelve-hole bearing circle, central spigot and machined mounting pads – GY Machining
6061-T6 · bearing face · 12-hole circle
Typical requirements

Bearing fits, concentricity and mounting faces

Almost every robotics part we make comes down to a bearing bore and the features around it. The housing in the photo is a 6061-T6 prototype: bearing bore, 12-hole circle and mounting pads cut in two setups. Nineteen of our 32 machining centres are four-axis, so a housing with bores on more than one face can stay in a single setup and hold true position between them.

  • Bearing bore fitsISO 286 IT6 – IT7
  • Bore-to-bolt-circle concentricity0.01 mm, one setup
  • Bolt pattern positionØ0.05 mm
  • Mounting face flatness0.02 mm
  • Achievable, milled±0.002 mm on critical features
  • Surface finishRa 0.8 – 1.6 µm
  • Four-axis centres19 of 32
  • Typical quantity1 – 500
  • Unmarked dimensionsISO 2768-mK
Case

Motor swing arms and joint links for gimbals, drones and small robot arms

Polished CNC machined aluminium robot joint links and motor swing-arm brackets for gimbals, drones and small robotic arms, machined by GY Machining
Joint links · motor swing arms · bright finish
What the customer needed

Elbow and shoulder joint brackets that a motor bolts straight into

These are the arms that carry a motor in a gimbal, a drone or a small robotic arm: a bearing seat at one end, a motor bolt pattern at the other, and a thin web between them that has to stay flat. We machine the family as a set — link, swing arm and the motor housing they mount to — so the bolt circles and bores are cut to the same datums and the joint goes together without shimming.

  • Part familyJoint links, swing arms, motor housing
  • Used inGimbals, drones, small robot arms
  • Critical featuresBearing bore, bolt circle, web flatness
  • FinishPolished bright
Quote a similar part
Questions

What buyers in this industry ask

How fast can you turn a revision around?
Quote in 16 hours, parts usually 7–15 working days. For a revision of a part we have already made, the setup and program exist, so it is normally at the fast end — tell us the previous part number in the RFQ and we will find the file.
Can you hold concentricity between bores on different faces?
On a four-axis setup, yes — around 0.01 mm, because the part is not re-clamped between faces. If the drawing needs better than that, or the geometry forces two setups, we will say so in the quote rather than discover it on the first article.
Do you do small assemblies?
Simple ones, yes — pressing in bearings and bushings, fitting dowels, thread inserts and light sub-assembly. We are not an assembly house, so anything involving electronics, wiring or calibration stays with you.
Processes used

How we make them

CNC Milling

Housings, plates and brackets on 3- and 4-axis centres. CNC milling →

CNC Turning

Shafts, bushings and fittings on twelve lathes. CNC turning →

Inspection

First article on the CMM before the run continues. Quality →

Ready for a quote?

Send the drawing — price and lead time within 16 hours. STEP, IGES, X_T, DWG, DXF or PDF.
No minimum order.

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