CNC Machine Buying Questions, Answered

Count the faces. If the part is machined from one side and the setup is quick, a vertical centre costs less and is easier to load. If the part needs three or four faces done in one clamping, a horizontal with a pallet changer pays for itself in setup time and in the accuracy you keep by not re-clamping. Horizontals also clear chips better, which matters on long unattended runs and on cast iron.

Box ways carry a wide sliding contact on an oil film, which damps vibration and suits heavy roughing, interrupted cuts and tough material. Linear guides roll instead of slide, so they move faster and accelerate harder, which suits high-speed contouring and light alloy. Most work sits in the overlap. There is a fuller comparison, with cross-sections, on our about page.

If the geometry is a true sculptured surface, an impeller or a blade, you need simultaneous five-axis. If you are reaching several faces at compound angles but each cut is still three-axis, 3+2 positioning does the job for considerably less money and is easier to programme and staff. Send the part and we will tell you honestly which one it needs.

Allow for the fixture, not just the part. As a working rule the table wants to be around one and a half times the part footprint once workholding is on it, and the Z travel has to clear the longest tool with the part at its tallest point. Table load rating matters as much as size: a small heavy casting can exceed a table long before it runs out of room.

The control is named in the contract rather than left as “CNC system”. Fanuc, Siemens and Mitsubishi are the usual choices for export machines, and we will fit whichever your programmers already know, because operator familiarity is worth more than a spec-sheet comparison. Domestic controls are available where budget outweighs familiarity.

Belt-driven, direct-drive and built-in motor spindles. Belt drive gives torque low down and suits heavy cutting in steel and cast iron. Direct drive removes the belt as a vibration path and holds finish better. Built-in motor spindles reach the speeds that light alloy and small cutters need. The choice follows the material and the finish you have to hold, not the headline rpm figure.

Named brands, written into the contract by model number. Linear guides and ballscrews are typically HIWIN, PMI, THK or NSK; spindle bearings come from established Japanese or European suppliers. Nameplates are photographed before the machine is crated and the photographs travel with the machine documents, so what you ordered and what arrives can be checked against each other.

Yes. Travels, table size, column height, coolant arrangement, chip conveyor type and automation are all configurable, and a large share of what we build is not a catalogue machine. Non-standard configurations add to the lead time because the castings and the guarding change, so tell us early if the part will not fit a standard envelope.

Armless carousels typically hold 16 to 24 tools; arm-type magazines run from 24 to 40 and upwards, with faster tool change. Size the magazine against the whole family of parts you plan to run, not one job, and leave room for sister tooling if the machine will run unattended.

ISO 230-2 is the standard for measuring positioning accuracy and repeatability of a numerically controlled axis. A laser interferometer is set along each axis, the axis is driven to a series of target positions from both directions and the error is recorded. The report gives positioning accuracy and repeatability per axis over the full travel, with the machine serial number on it. Repeatability is the figure to read first: it tells you what the machine will hold shot after shot.

Yes. Every machine cuts a test piece and the piece is measured, not just looked at. Where you have supplied a sample part we will cut that instead, which is far more useful than a standard test block because it proves the machine against your tolerance rather than a generic one.

Yes, and we would rather you did than take the report on trust. SGS, TUV, BV and your own engineer are all welcome to witness acceptance testing before the machine is crated. Agree the inspection scope when the order is placed so the machine is at the right stage when your inspector arrives.

Beds, columns and saddles are cast in Meehanite-practice iron and aged outdoors in our own yard before any cutting starts, so the residual stress in the casting relaxes before the geometry is machined rather than after the machine is in your shop. Guideway faces on box-way machines are then hand-scraped against a reference straightedge.

A serial-numbered inspection report with the laser measurements, the test-piece results, the nameplate photographs of the main components, electrical and pneumatic diagrams, the parts list, and operation and maintenance manuals. Certificates of origin, packing lists and any certification agreed for the destination go with the shipping documents.

Read the quotation for what is missing rather than what is listed. Cutting tools, toolholders, workholding and fixtures, foundation work, the site transformer if the supply does not match, import duty and local taxes, and engineer travel for installation are the items most often quoted separately. We list them as separate lines so the comparison against another quotation is like for like.

All three, and it is worth asking for more than one. FOB Shanghai suits buyers with their own freight forwarder. CIF puts the sea freight and insurance on us to your named port. DDP delivers to your door with duty paid, which is simplest but requires us to price your local charges. Comparing two suppliers only works when both quotes use the same term.

Not by default, because tooling is specific to your part and most buyers already have a supplier and a preferred holder taper. We will quote a tooling package against your drawing if you want the machine to arrive ready to cut, including holders, collets, a vice or a dedicated fixture.

Quotations carry a stated validity, typically 30 days, because casting, control and linear-motion component prices move. Freight is the most volatile line of all and is re-checked at order. Where a project runs longer than the validity we will say what has changed rather than quietly re-price the whole machine.

The configuration is confirmed in writing, castings are drawn from the ageing yard and machined, guideway faces are scraped where the machine has box ways, the machine is assembled in a temperature-controlled hall, then levelled, laser-measured and run in. Acceptance testing and the test piece come last, before crating. You can ask for photographs at each stage, or come and watch.

Machined surfaces are coated with rust preventative, the machine is wrapped in VCI film with desiccant, bolted to a fumigated timber skid and cased. Loose items, the toolkit and the documents travel in a separate marked box inside the case. Tilt and shock indicators can be fitted on request, which is worth doing if the machine transships.

Shanghai, roughly two hours by road from the plant. As a guide, sea freight runs about 30 to 35 days to Northern Europe, 25 to 30 to the US West Coast and 18 to 22 days to Southeast Asia, before customs clearance at your end. Larger machines that exceed container dimensions ship as breakbulk or on a flat rack, which changes both the cost and the schedule.

Yes. Commercial invoice, packing list, bill of lading and certificate of origin are prepared as standard. CE marking can be arranged for machines going into the EU. Tell us the destination country at enquiry stage, because the certification route is quoted with the machine rather than added afterwards.

Whatever your site runs. 380 V at 50 Hz is standard for China and much of Europe; 220 V, 415 V, 440 V and 460 V at 60 Hz are all available, and a matching transformer is fitted where the supply does not match the machine. Confirm the site voltage, frequency and phase at order, because rewiring after arrival is slow and avoidable.

Positioning on the foundation, levelling on the machine feet with a precision level, connecting power, air and coolant, powering up and checking the axes, re-checking geometry after transport, then cutting a part. Levelling is the step that gets rushed and the one that shows up later as taper and out-of-square work, so it is done properly before anything is signed off.

Wear items and common electrical parts are held in stock and go out by courier, typically within a few days of the request. Control and drive components come from the original supplier, so the lead time follows theirs. Quote the machine serial number when you ask and the right part is identified first time, which is the usual cause of delay.

Yes. Most faults are diagnosed from the alarm code, a photograph of the screen and a short video, over email or WhatsApp, in the same working day. Where the control supports it, a network connection allows the parameters and ladder to be read directly. An engineer travels only when the fault genuinely needs hands on the machine.

Technical support continues for the life of the machine at no charge, and spare parts remain available. Chargeable service visits, retrofits and accuracy re-checks can be arranged. A machine bought from us in 2010 can still get a part and an answer, which is the point of naming the components in the contract in the first place.

Yes. Operation and maintenance manuals, electrical and pneumatic diagrams and the parts list are supplied in English, along with the original control manufacturer's documentation. Other languages can be arranged where the destination requires them. Ask at order stage rather than after shipment.