Machine Selection Guide
Choosing a machine is one of the biggest decisions a shop makes. It's not about buying the most expensive or most capable machine — it's about matching the machine to the parts you actually make.
Decision Factors
| Factor | Questions to ask |
|---|---|
| Part geometry | Cylindrical? Prismatic? Complex 3D? |
| Part size & weight | Diameter/length? Does it need a VTL or lathe? Table load? |
| Material | Aluminum (high speed) or steel (high torque)? |
| Tolerances | ±0.05 mm or ±0.005 mm? Drives accuracy class. |
| Operations needed | Turning only, or turn-mill? Drilling? Grinding? |
| Production volume | One-off (VMC fine) or 10,000/year (HMC + automation)? |
| Budget & ROI | What's the payback? Can you use existing tooling? |
Quick Decision Tree
Part is cylindrical?
→ Short, large diameter, heavy? → VTL
→ Long, small diameter? → Horizontal CNC lathe
Part is prismatic?
→ One-off, plates, molds? → VMC
→ Production, multi-sided? → HMC
→ Complex 3D surfaces? → 5-axis
Need precision on hardened parts? → Grinder
Need internal corners in hard material? → EDM
Example: A shop grows from prototype to production
Job shop starts with a VMC — perfect for one-offs and prototypes. As production volumes grow, they're flipping parts 4 times on the VMC and losing money. The next investment is an HMC with a pallet changer: load 4 parts, walk away, come back to finished parts. The VMC stays for prototypes. Neither machine replaces the other — they serve different jobs.