5-Axis Machining
Kitamura Mytrunnion 4G — what we run on it.
Trunnion-style 5-axis with a 24″ × 24″ × 19.7″ envelope. Used for parts that need 5-sided machining in a single setup — aerospace brackets, medical implants, complex housings. Typical accuracy on a finished part: 0.0005″ positional, 16 µin Ra.
01 · Specs
The machine.
- Travels (X / Y / Z)
- 24″ × 24″ × 19.7″
- Trunnion (A / C)
- A: ±120° · C: 360° continuous
- Spindle
- CAT-40, 12,000 RPM, 25 HP
- Coolant
- 300 PSI through-spindle, flood, mist
- Tool capacity
- 40 stations, dual-arm ATC
- Probing
- Renishaw OMP60 spindle probe + tool setter
- Positioning accuracy
- 0.0001″ over full envelope
- Max workpiece weight
- 660 lb
02 · Sweet spot
What this machine is for.
The Mytrunnion is our go-to for parts that need simultaneous 5-axis or 5-sided machining where the work would otherwise need 3+ setups on a 3-axis mill. Real applications:
- Aerospace brackets & structural fittings — titanium, 7075, 17-4PH. Pocketed both sides + angled mounting bosses + threaded inserts. 5-axis lets us do all 5 sides in one fixture.
- Medical surgical-tool housings — Ti-6Al-4V or 17-4PH. Angled probe ports, conformal cooling channels, complex sealing surfaces. Critical features under 0.001″ — single setup eliminates stack-up.
- Optical / sensor mounting plates — 6061 or MIC-6. Angled mounting interfaces with shared datum. 5-axis maintains parallelism between non-coplanar features.
- Complex Inconel valve bodies — port angles, bosses, internal passages. The 25 HP spindle handles the heavier roughing cuts; ceramic inserts at 700 SFM.
- Defense fastener & mount geometry — angled through-bolted assemblies where TIR between datum-A and angled threaded holes is <0.0005″.
03 · Fixturing
How we hold the work.
Trunnion machines have a fundamental fixturing constraint: the part swings through the spindle envelope as the trunnion tilts, so fixtures need a small footprint and clear access on all 5 sides. Our standard approaches:
- Schunk Vero-S quick-change pallet system — base pallet bolted to the trunnion C-axis face plate, sub-pallets swap in 90 seconds with 0.0002″ repeatability. Pre-set fixturing offline keeps the machine cutting.
- Mitee-Bite low-profile clamps — for parts that need to be held from one face only. Profile keeps the clamps out of the spindle path.
- Custom soft jaws — for production runs over ~200 pieces. We machine the soft jaws on the same machine for perfect alignment.
- Sacrificial tabbing for tiny parts — parts under ~0.5″ get held in stock with sacrificial tabs, machined complete in 5-axis, then cut free in a separate op.
04 · Programming
CAM strategy.
We post 5-axis programs from ESPRIT using the Mytrunnion-specific post processor that supports tool-tip programming (TWP/TCP). Standard strategies:
- 3+2 indexed for most work. Trunnion locks at fixed angles and machines like a 3-axis. Simpler, faster, more predictable surface finish. ~85% of jobs run this way.
- Simultaneous 5-axis for blends & sweeps. Used for impellers, contoured optical surfaces, conformal cooling channels. Slower but produces surface finish + form accuracy that 3+2 can’t.
- Vericut simulation for everything new. Catches collisions before they happen on a $250K machine. Mandatory for any program with simultaneous 5-axis motion.
- Probe-set work coordinates. Renishaw OMP60 sets WCS off the trunnion C-axis center. Rotational center calibrated weekly with a 1″ precision sphere.
05 · When NOT to pick this machine
Wrong-fit jobs.
The Mytrunnion is excellent at 5-sided medium-precision work, but several jobs run better elsewhere in the shop:
- High-volume single-setup parts → Doosan DVF 5000. The DVF has 8-pallet automation for lights-out runs; the Mytrunnion is single-fixture only.
- Large flat plates / 2D-dominant work → Haas VF-6 or DNM-4500. The Haas has 64″ X travel; the Mytrunnion is 24″.
- Bar-fed turn-mill parts → Doosan SMX 2600. Mill+turn in one chucking is faster for prismatic + cylindrical hybrid parts than tying up the 5-axis.
- 0.0001″ class jig-grinding work → Wire EDM (Fanuc Alpha 1iD). 5-axis milling tops out around 0.0002″ for square features; tighter geometry needs grinding or EDM.
Inspection
How we verify 5-axis work.
For most 5-axis jobs we run in-process probing — Renishaw OMP60 verifies critical dims after each toolpath, alarm if out-of-tolerance. Final inspection moves to the Hexagon Global S 7-10-7 CMM for AS9102 FAI or PPAP packages. CMM picks up GD&T callouts (true position, profile of a surface, runout) that probing can’t verify in-process.
Optical surfaces and conformal channels also get a Keyence VR-6200 scan for surface profile + form deviation, which catches issues a tactile CMM can miss.
Got a 5-axis part you'd like to talk about?
Send a drawing or STEP — we'll tell you whether the Mytrunnion is the right fit, or whether something else in the shop fits better.
Quotes in 24 hours