How to specify 5-Axis Machining Centre on a drawing

5-Axis Machining Centre is a machining centre that can orient the cutter or the workpiece on two additional rotary axes. It is used for parts with compound angles, deep cavities and features that would otherwise need several setups. This entry explains what it is, what the numbers on a data sheet mean, and what to put on a drawing.

It is written from the point of view of the buyer and the drawing office: the values that are realistic in production, the ones that cost money, and the way the result is verified. Where an industry sets the requirement, rail is used as the example: documented welds, coatings and fire smoke toxicity compliance.

What belongs on the drawing

A clear drawing for 5-Axis Machining Centre states the function, the tolerance and the verification, and leaves the route open where the function allows it.

• The feature and its tolerance: ±0.01 mm, applied to the features that locate the part.
• The material and its condition: Ti-6Al-4V titanium, with the certificate requirement.
• The surface finish: Ra 0.8 µm achievable with a finishing pass, called out only where it does something.
• The verification: AS9100 with material traceability, and the standard the report is written to.

Mistakes that cost money

• The tool centre point not compensated, so the length is wrong as soon as the head tilts, which makes the part more expensive without making it better.
• Collision between the holder and the part, which only shows up in a simulation, which makes the part more expensive without making it better.

A workable note

Where a general note is used, say so once in the title block and keep the feature level call outs for the dimensions that matter. Tolerance the locating datums and leave the free form surfaces general toleranced

Applications

5-Axis Machining Centre is used for parts with compound angles, deep cavities and features that would otherwise need several setups, and in practice it appears most often in impellers and blisks, aerospace structural parts, medical implant trials, mould cores.

How it fits into a machining route

The route is fixed before the first part is cut, and it is the route rather than the individual setting that holds the result: programming time and simulation, not machine hourly rate. Where a drawing calls for something the route cannot hold economically, that is raised at quotation rather than after the parts are made.

Standards, documentation and what is issued

The documentation requirement is AS9100 with material traceability. Material is supplied against a certificate where the application calls for it, inspection results are recorded with the job, and the records are kept so that a repeat order can be compared with the first instead of being measured from scratch.

CMM with a five axis probe head, or structured light scanning for free form faces is the verification step. Where a customer format or a standard report is required, it is agreed before the batch starts, because a report written after the event is a report nobody can use.

Frequently asked questions

What tolerance should be specified for 5-Axis Machining Centre?

±0.01 mm is realistic in production. Tightening it beyond the functional requirement increases cost without improving the part.

Which material is usually used?

Ti-6Al-4V titanium is the usual choice, supplied against AS9100 with material traceability.

How is the result verified?

CMM with a five axis probe head, or structured light scanning for free form faces, with the results recorded so a repeat order can be compared with the first.

What is the most common mistake?

Collision between the holder and the part, which only shows up in a simulation.

How long does it take and what does it cost?

A realistic cycle is 40 to 120 minutes for a complex part, and the cost driver is programming time and simulation, not machine hourly rate.

Related capability

If you are specifying 5-Axis Machining Centre on a drawing and want a second opinion on the route, send the model and the quantity. The first response is a manufacturability review with the likely risk points and a quotation, so the decision can be made on facts rather than on a price alone.

Machining, inspection and documentation are handled in one place, which is why the dimensional report and the material certificate arrive with the parts rather than after them.

Related entries

These entries sit next to 5-Axis Machining Centre in the encyclopedia: Coordinate Measuring Machine, CNC Drilling Machine, Hard Milling. Reading them together gives a fuller picture of how the process, the material and the measurement affect each other.