VMC Machining
VMC machining is CNC milling on a vertical machining centre, where the spindle points down onto the workpiece. VMCs are the workhorse for prismatic parts such as plates, housings, brackets and fixtures, combining milling, drilling, boring and tapping in one setup.
What it is
A VMC holds the part in a vice or fixture on a moving table, with an automatic tool changer loading end mills, drills, taps and boring bars as the program runs. Several operations are completed without the operator touching the part.
With a rotary 4th axis added, a VMC can also machine several faces of a part in one clamping, improving accuracy between features.
Typical applications
- Machine parts and base plates
- Gearbox and pump housings
- Hydraulic manifolds and valve blocks
- Jigs, fixtures and tooling
- Automotive and automation components
Suitable materials
- Aluminium
- Mild steel and alloy steels
- Stainless steel
- Cast iron and steel castings
- Engineering plastics
Points to consider
- Fixtures and setups drive cost at low volume; dedicated fixtures pay back on repeat production.
- Datum surfaces should be clear on the drawing so every setup references the same features.
- Castings and forgings need clear datum features or locating points for the first operation.
- Tight positional tolerances between faces benefit from 4th-axis or single-setup machining.
Frequently asked questions
What does VMC stand for?
VMC means Vertical Machining Centre, a CNC milling machine with a vertical spindle and automatic tool changer.
What is the difference between VMC and HMC?
A VMC has a vertical spindle and suits plates and smaller prismatic parts. An HMC (horizontal machining centre) has a horizontal spindle and a pallet changer, better for heavy, multi-face production parts.
Can a VMC machine castings?
Yes. Castings and forgings are routinely finish-machined on VMCs once suitable locating datums are established.