CNC From Solid
Monolithic Frame Parts

A monolithic machined frame is a single-piece structural component machined from solid billet that replaces a multi-part welded or bolted frame assembly. All structural interfaces, mounting faces, and load-transfer features are machined from one coordinate origin — eliminating weld distortion, joint stiffness variation, and assembly tolerance stack-up.

(1) No weld distortion — welded frames distort 0.5–3 mm over typical equipment frame sizes; (2) No post-weld re-machining — all interfaces are correct in the machined state; (3) Better fatigue life — no weld heat-affected zones that initiate fatigue cracks; (4) Cleaner for medical/food environments — no weld bead voids that trap contamination; (5) ±0.01 mm interface accuracy — impossible to achieve reliably with welded assemblies.

For small to medium frames (<500 mm, <5 kg), monolithic machining is often comparable in cost to welding + post-weld re-machining when labour, distortion rework, and CMM inspection time are included. For large frames (>500 mm), the billet material cost increases, but the elimination of fixturing and re-work stages brings the total cost closer. HXC provides a cost comparison on request.

Standard 5-axis machining envelope: 800 × 600 × 500 mm. For larger frames up to 1,200 × 800 mm, we use precision fixture indexing on our 4-axis gantry machines, maintaining interface positional accuracy by re-referencing to on-machine probe measurements between setups.

Al 6061/7075: most common — lightweight, excellent machinability, anodizable. 42CrMo4 / C45 steel: for high-load frames requiring rigidity and wear surfaces. SUS304/316L: for food, medical, and cleanroom equipment frames. Ti Grade 5: for weight-critical aerospace frames. Cast iron can be considered for very large machine tool frames.

Large frame roughing removes >70% of billet material, releasing residual stress. HXC manages this by: (1) two-stage roughing with a stabilisation period between stages; (2) natural ageing (room temperature stabilisation, 24–48 hours); (3) for critical frames, vibratory stress relief as an optional process. Finishing passes are made only after stress relief.

Yes — internal cooling channels and cable routing bores are machined by gun drilling or deep-hole drilling (L/D up to 30:1) before or during the main machining operations. Intersecting channels are designed with plugged access ports. HXC drills and verifies internal channels as part of the main machining scope.

Prototype (complex monolithic frame, custom workholding): 9–14 days. Small batch: 14–20 days. Production: 20–30 days. Large frames (>600 mm) add 3–5 days.