6061 Robot Five-Axis Connection Flange CNC Case Study

This circular connection flange looks geometrically simple, but it locates and locks two robot joint modules. The manufacturing challenge is not merely drilling every hole; the center bore, stepped end face and two circumferential patterns must remain in one stable datum relationship.

Project Snapshot

Determine The Functional Datums First

Before programming, OEMach identifies which bore locates the module, which face provides contact and which hole circle creates the clamping force. These functions determine the setup, toolpath and inspection order.

If the center bore is unstable, module location changes. If angular spacing between the outer and inner patterns drifts, screws can load the joint unevenly. The stepped face may also provide contact or clearance, so burrs and residual particles at its root cannot be treated as cosmetic details.

Machining Route: Stabilize The Center Relationship

The process begins by establishing parallel faces and a reliable center datum. Rough machining leaves finishing allowance on the outside profile and steps. After the disc stabilizes, the center bore, outer mounting pattern and inner threaded pattern are completed from a consistent locating state.

Keeping both circular patterns in one setup reduces angular accumulation from repeated flipping. Chamfers must remove burrs without reducing screw contact area or creating an uneven bright line after black anodizing.

Control The End Face In The Free State

A thin circular flange can appear flat while clamped and relax after release if the support is uneven. That movement changes the practical relationship among the center bore, stepped face and hole patterns.

Uniform support and soft location distribute force around the disc. The first part is released and rechecked before the batch continues. This extra check prevents a fixture-induced shape from being mistaken for the real delivered condition.

Inspection Covers The Combined Relationship

First-article inspection covers the center bore, face flatness, face steps, outer pattern, threaded inner pattern, chamfers and black appearance. The key result is not whether one hole passes in isolation, but whether center, face and hole circles remain stable together.

During the batch, tool wear, fixture repeatability and post-anodizing hole edges are monitored. The structure is regular, but repeatable assembly behavior is what matters to the customer.

Black Anodizing, Lead Time And Packaging

Black anodizing does not hide machining defects. Bright hole edges, tool marks at step roots and scratches can become more visible. Before coating, the team checks cleanliness, chamfer consistency and cosmetic surfaces; after coating, color, residue and critical dimensions are checked again.

Prototype lead time is typically evaluated at 5 to 8 working days, with small batches planned at 8 to 12 working days. A complete hole-position report requires additional inspection capacity. Each flange is located in foam to protect its end faces, hole mouths and black finish.

Case Study Summary

The value of this five-axis connection flange lies in creating a repeatable assembly relationship among the center bore, stepped face and two circular hole patterns. Functional datum review, controlled clamping, combined inspection, anodizing management and protected packaging form one closed delivery process.

FAQ

Why is a circular robot flange difficult to machine?

Its difficulty lies in the relationship among the center bore, end face and multiple hole circles. Each feature may pass alone while the full assembly relationship is still incorrect.

Why recheck the flange after unclamping?

Uneven support can temporarily flatten a disc. Free-state reinspection reveals distortion that could affect assembly.

What should be inspected after black anodizing?

Check critical fits, hole edges, threaded features, coating residue, color consistency and scratches on visible surfaces.