3-axis, 4-axis or 5-axis: what does your work need?

When is a 4th axis enough, and when does a part need five?

A 3-axis machine moves in X, Y and Z, but the part never turns and the tool always points the same way. A hole or pocket on another face means unclamping the part, turning it and setting it up again.

On a VMC, the 4th axis is a rotary table on the machine's table. It turns the part about one axis, so the faces and features around that axis come to the spindle in one clamping. Some 4th axes only index, turning to an angle and locking while the spindle cuts; a full 4th axis can also turn while it cuts.

A 5-axis machine has two rotary axes that tilt and turn the part or the head. Hwacheon's 5-axis catalogs list what that adds: the tool can come at the work from any direction, including undercuts a 3-axis machine cannot reach; shorter tools do the job; and a ball end mill can cut with its side instead of only its tip.

A 5-axis machine works two ways, and Hwacheon's catalogs name both. In 3+2 work, the rotary axes tilt to an angle and hold it while X, Y and Z cut. Simultaneous 5-axis moves all five at once, so the tool can stay tilted to a curved surface as it cuts.

So the part decides. If turning it about one axis brings every feature to the spindle, a 4th axis does it. If it does not, because a feature is tilted in two directions or sits behind an overhang, or a surface has to be cut with the tool tilted, the part needs the fifth axis.

How is a 4th axis added to a VMC?

It takes an interface on the machine for the rotary table, and for a full 4th axis, a fourth axis in the control. On Hwacheon's machines these are options:

• •On the VESTA-1100, the standard FANUC 0i-MF Plus controls three axes. The 4-Axis Interface option brings the 4-axis functions with it: a fourth controlled axis, four simultaneous axes and cylindrical interpolation, for features wrapped around a diameter.
• •On the HiT series of tapping centers, Hwacheon lists a Rotary Table (4-Axis) and a Rotary Table Interface as options, and an Index Interface on the HiT-400 and HiT-400L.

For a machine you already own, start from its builder's option list for that model, with the make, model and control in hand.

For the table itself, the Add-ons on our Machines page list NIKKEN for rotary tables and tool holders and Golden Sun for rotary tables.

How big a part fits on a 5-axis machine?

On a tilting-table machine the part and its fixture tilt and turn with the table, so the table's size and load rating set the work it takes. When a part is too big or too heavy to swing, the rotary axes go in the head instead: the SIRIUS-2500/5AX and SIRIUS-3000/5AX carry a universal head, and Hwacheon builds them for large dies and molds.

The eight Hwacheon 5-axis machines on our Hwacheon page, lightest table load first:

Hwacheon · Multiplex 5-axis machining centersBuilt to orderD2-5AX5-axis vertical machining center for parts machining12K · 14K · 20K · 24K

X / Y / Z travel

25.6 / 19.7 / 19.7 in

Table size

Ø23.6 in

Spindle

BBT-40 up to 20,000 rpm; HSK-A63 at 24,000 rpm

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Hwacheon · Multiplex 5-axis machining centersBuilt to orderM1-5AXHigh precision 5-axis vertical machining center for parts20K · 32K

X / Y / Z travel

29.5 / 19.7 / 17.7 in

Table size

Ø11.8 in

Spindle

BBT-40 20,000 rpm or HSK-E40 32,000 rpm

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Hwacheon · Multiplex 5-axis machining centersBuilt to orderM2-5AXHigh precision 5-axis vertical machining center20K · 32K

X / Y / Z travel

29.5 / 25.6 / 19.7 in

Table size

Ø19.7 in

Spindle

BBT-40 20,000 rpm or HSK-E40 32,000 rpm

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Hwacheon · Multiplex 5-axis machining centersBuilt to orderSIRIUS-2500 5AX5-axis angle head vertical machining center for die and mold

X / Y / Z travel

122.0 / 90.6 / 39.4 in

Table size

129.9 x 78.7 in

Spindle

BBT-40, 15,000 rpm

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Does the control move all five axes at once?

Not on every machine as standard. The D2-5AX and D3-5AX come with a FANUC 0i-MF Plus that Hwacheon lists as 4+1 axis controlled: five axes under control, four of them moving at once. Simultaneous 5-axis is the FANUC 31i-B5 Plus option. The M1-5AX, which runs Hwacheon's HARMONY on a FANUC 31i-B5 Plus, and the M2-5AX, M3-5AX and M4-5AX list five simultaneous axes as standard.

If your parts need the tool tilting while it cuts, ask for simultaneous 5-axis control on the quote.

Can a 5-axis machine change its own parts?

Hwacheon's AWC is an automatic workpiece changer for the D2-5AX and M1-5AX. It holds 8, 20 or 40 workpieces on holders with an HSK-T100 interface, with a setup station of its own for loading raw parts and collecting finished ones. On the 8 and 20-position versions a workpiece can be up to 16.5 x 6.7 in (420 x 170 mm), or Ø11.8 in (Ø300 mm) if round, and 176 lb (80 kgf); the 40-position version takes round parts up to Ø5.9 in (Ø150 mm) and 66 lb (30 kgf). The weights include the work holder.

With the AWC, the D2-5AX's standard table is the Ø19.7 in (Ø500 mm) round table. For other machines, Hwacheon's catalog calls for technical consultation. For robots, gantry loaders and pallet systems, see the guide to automating a CNC lathe or mill.

Hwacheon · AutomationBuilt to orderAWCAutomatic workpiece changer8P · 20P · 40P

Compatible machines

D2-5AX, M1-5AX

Workpiece capacity

8, 20 or 40 (8P, 20P, 40P)

Max workpiece size

16.5 x 6.7 in or Ø11.8 in

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What should I settle before ordering a first 5-axis machine?

• •The largest part with its fixture, against the table size, the load rating and the travels.
• •Spindle and taper, matched to the holders you run. BBT-40 is standard on the D2-5AX, D3-5AX, M1-5AX, M3-5AX and SIRIUS-2500/5AX, BBT-50 on the M4-5AX and HSK-A63 on the SIRIUS-3000/5AX, and the M1-5AX and M2-5AX offer a 32,000 rpm HSK-E40.
• •Tool count. The D2-5AX, D3-5AX, M1-5AX, M2-5AX and M4-5AX carry 30 tools standard, the M3-5AX and SIRIUS-2500/5AX 40, and the SIRIUS-3000/5AX 90. Options run to 60 on the M1-5AX, M2-5AX and D3-5AX, to 90 on the M3-5AX and M4-5AX, and to 120 on the D2-5AX.
• •The control: simultaneous 5-axis or 4+1.
• •CAM and a post-processor. Simultaneous 5-axis programs come from CAM software, through a post-processor made for the machine and its control. Hwacheon's H-SIMUL 5X machining simulation is standard on the M1-5AX and an option on the D2-5AX, D3-5AX, M3-5AX and M4-5AX.
• •Probing. Renishaw or Blum tool and workpiece probes are options on the six tilting-table machines, and so is HRCC, Hwacheon's system that measures and sets the center of the rotary axes.
• •The first part. Before you order, ask who writes the post-processor and who proves out the first part, and get the answer in writing.
• •Power, air and floor: see what your shop needs ready before a CNC machine arrives.