Three levels of lathe complexity
| Capability | What it adds | Post challenges |
|---|---|---|
| Y-axis | Off-centre milling and drilling with live tools | Plane selection, Y moves, C-axis clamping |
| Sub-spindle | Machining both ends in one cycle | Part transfer, sync, back working coordinates |
| Multi-channel | Two or more tools cutting at once | Separate programs, wait codes, timing |
Y-axis lathes
Without a Y-axis, off-centre features need C-axis interpolation (polar or cylindrical). With a Y-axis, the live tool can move off centre directly, giving true flats, pockets and off-axis holes. The post must choose the right plane for face and side work, output Y moves, clamp or position C as needed, and switch between turning and milling modes cleanly. See Y-axis lathe posts.
Sub-spindle lathes
A typical done-in-one sequence is: machine the first end, move the sub-spindle in, grip, synchronise spindles, cut off, retract and machine the back end. Fusion has operations for part transfer and cut-off; the post turns them into your machine's codes for sync, clamping, positioning and torque or position checks. On the sub-spindle, Z direction and offsets change, so back working coordinates must be handled carefully. See sub-spindle posts.
Multi-channel machines
On machines with two or more turrets, each channel runs its own program. The programs meet at wait points, which keep channels in step. Wait syntax is control-specific, and the exact codes are defined by the machine builder. A simplified example with two channels:
(CHANNEL 1) (CHANNEL 2)
T0101 T0303
(wait 10) (wait 10)
G1 X20. F0.2 G1 X30. F0.15
(wait 20) (wait 20)
M30 M30Every wait number in one channel must match the same wait number in the other. A missing wait can stall the machine or cause a collision. See multi-channel posts.
Machine definitions and simulation
For advanced lathes, a Fusion machine definition with spindles, turrets and axes makes simulation meaningful. Simulating transfers and parallel cutting before trials catches most problems. Final proving should start in single block with conservative overrides.
The more a lathe can do in one cycle, the more the post must know about it.
Checklist before you start
- Machine model, control and options (Y-axis, sub-spindle, channels)
- Builder codes for sync, transfer, clamping and waits
- Proven programs from the machine
- How your team wants operations ordered between channels
- Bar feeder, part catcher and conveyor details
Advanced lathe post services
See Fusion mill-turn posts, and read dual spindle post processors and multi-turret post processors.