GlossaryKind of term: Manufacturing termComplete machining (done in one)
What is complete machining?
Complete machining means machining a part, front and back, on a single machine, with no transfer to another machine in between.
It runs from stock to a fully machined part; how the back gets machined depends on the machine. On a mill-turn centre or Swiss-type lathe with a sub-spindle, the sub-spindle takes the part over and the back is finished there. On a 5-axis machine the part can be machined from bar or on a clamping margin and then finished in a second fixture on the same machine, moved there by a robot or by hand. Whether a manual reclamp on the same machine still counts as complete machining varies between shops. Post-treatments such as hardening or anodising fall outside it.
When can a part be machined complete?
Whether a part can be machined complete depends on the machine and the part together: the kinematics and number of spindles, live tooling and a Y axis, the gripping surfaces for the transfer, access to the back, the number of tool stations and the stiffness of the part during the last operations. The transfer to the sub-spindle is an automated reclamp. How well front and back line up therefore depends on the alignment between main and sub-spindle, the surface the sub-spindle grips on, the repeatability of the clamping and the thermal behaviour of the machine. That is often better than a manual reclamp on a second machine, but it is not a given.
How does complete machining work in practice?
Complete machining shifts work from handling to the machine. Waiting between machines, manual reclamping and realignment can disappear, and less work in progress sits on the floor. The trade-off is usually a higher machine hour rate and more programming time. The cycle time on that one machine is often longer than either step of the two-machine route on its own, unless operations on main and sub-spindle run at the same time. Turret-mounted driven tools also usually have less power and stiffness than a machining-centre spindle, so heavy milling can take longer on a mill-turn centre. Which route is cheaper per piece depends on quantity, rates, the share of milling, the tolerances between front and back and the available capacity. For the same part, complete machining and a two-machine route are often both defensible.
What is complete machining often confused with?
Complete machining is not mill-turn: mill-turn is the process and the machine class, complete machining the outcome it can deliver, as a Swiss-type lathe or a 5-axis machine can. Nor is it necessarily one setup: the transfer to the sub-spindle is a second setup, only automated. Whether your estimate counts it separately is a matter of convention.
How do you see complete machining in Blake?
In Blake mill-turn is a process of its own, with material, machining, setup and programming as separate lines, per piece and per batch, at the hourly rate of the machine in the route. You enter the setups per route yourself and accept or undo them; whether you enter the transfer to the sub-spindle as a setup of its own is your call. The result is labelled as an estimate. More on mill-turn.
Frequently asked questions
When does complete machining pay off over a two-machine route?
That depends on quantity, hourly rates, the share of milling and the tolerances between front and back. The advantage grows when reclamping, waiting and realignment weigh heavily. For simple parts with little milling, a two-machine route is often defensible.
Is complete machining more accurate than reclamping on a second machine?
Often for dimensions between front and back, because manual alignment disappears. But the transfer to the sub-spindle is also a reclamp: the result depends on the alignment between the spindles, the clamping and the thermal behaviour of the machine.
Does a completely machined part come off the machine finished?
Finished as far as machining goes, if every feature can be reached in the machine. Deburring, a finish such as anodising or hardening and off-machine inspection can still follow.