Multi Axis Machining

한국델켐주식회사

정 찬 웅

What is multi axis machining?

• 4- axis• Positional 5-axis• Continuous 5-axis• Swarf machining

Benefits of 5-axis Machining

• Reduction of Setups• Improved surface finish• Allows machining of undercuts• Improved tool life• Less EDM required• Less bench work required• Shorter manufacturing times for cavities

Why 5 axis machining

• Market requirements for– Increasing flexibility– Improved productivity– Improvements in surface finish

• Technology advances in machine tools• Affordability of machine tools• Trend to machine shorter batch runs from

solid material– Linked to ever shorter product life cycle

Forecasted Use of 5-axis Machines by Worldwide

Mouldmakers

Remain steadyIncrease slowlyIncrease quickly

36.8%

57.9%

5.3%

Source : CIMdata April 2000

Application Areas

• Aerospace– Structures– Turbine?

• Turbine blades• Tool and die• Medical• Automotive• Marine

Aerospace structure

Thin walled angled wallsThat require swarf machiningWith cutter fanning round the corners

Fanning

Aero EngineBlisk (Bladed DISC)

Turbine Blade

Tool and DieTrimming (profiling around edge)

Tool and Die

Marine

Medical

Hip Joint

Dental

Prosthetics

5-axis machining• Three basic types of machine: -

– Head/head– Head/table– Table/table

• Two machining approaches: -– Positional (3 + 2) and

continuous• 5-axis machining is much more

complex that 3-axis machining, e.g. wider variation in post-processing

PowerMILL 4All 5 Axis Machine Tools are based on 3 configurations

•All Movement in the Head •Movement in Head and Table•All Movement in Table

All OTHER CONFIGURATIONSARE BASED ON THESE

PowerMILL 4

THINGS TO CONSIDER

•Part Position on the table

•Software Constraints

•Physical constraints

PowerMILL 4

Part Position on the Table

Limits are set in the Option File

Positioning the Part could result in Not being able to reach all Areas

PowerMILL 4

Software ConstraintsFind out about the control•Type?•Coordinate transformation?•Linearization?

PowerMILL 4

Physical constraints•Linear and rotary limits?•Will the job fit on the machine? •Can you rotate the tool to get to all areas?

Typical Machine Tool Kinematics

• Two main types of 4 axis machining– Table rotation in C– Table rotation in B

• Three main types of 5 axis machines– Head rotation– Head rotation and table rotation– Table rotation in two axis

• Hexapod Type

What the letters mean

•On most machines, the A,B,and Caxes correspond to X,Y, and Z inthis way:

•The A axis pivots around a center line parallel to the X axis.

•The B axis pivots around a centerline parallel to the Y axis.

•The C axis pivots around a centerline parallel to the Z axis.

Head / Head type

Mecof fork typeHead rotation in C and A

Rye Gantry typeHead rotation in C and B

Head / Table Type

Head rotation in ATable rotation in C

Head rotation in BTable rotation in C

Table / Table Type

Head StaticTable rotates in CTable rotates in B

Mazak Variamatic

Table / Table Type (continued)

Head StaticTable rotates in CTable rotates in A(with A axis nutated)

DMG

Hexapod

View from above

5-Axis Positional Machining

• Machine head is aligned in a series of fixed positions

• Maximum rigidity as head is fixed during each machining stage

• Faster machining possible between head movements

Five-axis Positional Machining• Ideal for machining deep

cores and cavities• Undercut shading assists user

to orientate axes so avoiding collisions

• Short cutters give increased accuracy and higher quality surface finish

• Significant time benefits through reduced set-ups

Positional 5-axis (3+2 Machining)

73% of 5-axis users use 5-axis for positioning.(source: CIMdata April 2000 )

Five-axis Positional Machining

5 Axis Positional MachiningCompany DACMAC (UK)Machine DMU 50EReduction in operations from 12 to 2Parts now set off line (each set up Previously took 90 minutes). Positional 5 Axis with DMG and Delcam

has given Dacmac

• Quicker toolpath generation time• A reduction in costs• Improved flexibility• Improved accuracy • Better surface finish

Doong Ling Ltd., Taiwan• Major manufacturer of

moulds for bumpers• Uses 3 + 2 machining

for large moulds• “The high quality

surface finish produced with PowerMILL has reduced the time needed for hand finishing by 50%” Mr. Tsai, Owner

A.F. Gaskin, UK

• Mould maker and precision engineering

• Uses 5-axis to increase accuracy and reduce set-up times

• “5-axis machining saves a lot of time and money. It is essential to the future of our business” David Gaskin, Director

Continuous 5-Axis in PowerMILL

• Wide range of 5-axis strategies – through a line, through a point, profiling, trimming, pocketing etc.

• Automatic calculation of optimum lead and lag

• Gouge and collision checking on all toolpaths

• Supports full range of cutters

Tool axis direction

PowerMILL uses 5 different methods of orientatingThe tool axis.

Automatic Control of Lead and Lag Angles

Lead Angle- defines a rotation of theTool axis in the direction of travel, can bePositive or negative.

Automatic Control of Lean Angle

Lean Angle- defines a rotation of theTool axis at right angles to the directionof travel, can be positive or negative toIndicate a right/ left lean.

Towards a pointThe machining direction will always pass a point in space with thecutting end pointing towards the point at the start of the projection.

Pattern location

Plane Projection (pattern isPlane)

Pattern Location

Point/line projection (patternIs a sphere)

Towards a point

From a point

The machining direction will always passThrough a point in space with the cuttingEnd pointing away from the point at theStart of the projection.

Towards a line

The machining direction will always passthrough a user defined line in space withthe cutting end pointing towards the line. The tool axis is oriented towards a line at the Start of the projection.

Cutter Drive Issues

• Profiling keeps tool perpendicular to the edge at any particular point

• Drive surface machining keeps the tool parallel to the t or u direction at any particular point

• Swarf cutting keeps the tool parallel to the ruling direction at any particular point

Full Simultaneous 5 Axis Machining (Surface Normal)

5 Axis in PowerMILL

•The skirt of this Italian High Speed Train was manufactured using PowerMILL 5 Axis•Franco Calloni (Delcam Italia) used a combination of :-

•Positional 5 Axis [or 3+2]•5 Axis continuous with use of a reference surface as the drive curve.

5 Axis Machining using a Reference Surface as the drive

curve• Can be used as concept

prototype• Needs PowerSHAPE to

create the reference surface

• PowerMILL user can apply lead/ lean angle for tool that will use reference surface as the drive curve.

Drive Surface 5-axis

• Projection direction and tool orientation determined by drive surface

• Single drive surface but multi-surface part

• Full gouge protection• All cutter types

Video of 5 Axis Machining Using A Reference Surface

Machining normal to the surface

• Easiest method for programming but can be inefficient

• Only uses tip of cutter so wear is concentrated in a small area

• Contact is with centre of cutter so cutting speed is lower

• Can lead to greater movement of head than necessary

• Can be impossible to reach some areas without collisions

Swarf Machining

Swarf cutting is when you cut with the side of the tool. It can only work with developable surfaces where the ruling direction is perpendicular to the parametric direction you are machining along.

Machining with variable lead and lag

• Variation of cutting angle gives better cutting conditions and more even wear of cutter

• Head movement is reduced allowing faster machining

• Allows access to “difficult”surfaces without risk of gouging

5-axis machining of slots• Using 3-axis machining

with a ball-nose cutter will leave a fillet in the corners. The corner must then be finished by hand

• Using 5-axis machining with an end-mill, leaves a sharp corner, needing minimal hand finishing

• The reduction in hand finishing saves time and improves quality

5-axis machining of slots

5-axis profiling

• 5-axis profiling uses new-style cutters with longer flute length

• Allows smoother surfaces to be machined with fewer cutting operations

• Similar approach can be used for trimming e.g. of composite mouldings

Rojac, UK• Major supplier of models,

patterns and tooling to the automotive industry

• Uses 5-axis machining for deep cavities, trimming and drilling

• “With 5-axis machining, we can produce a better surface finish at a higher speed”Gerry Hart, CADCAM Manager

Rojac UK

5-Axis Drilling• CAM system can recognise

hole features defined in CAD system

• Main application in drilling holes at fixed angles to complex surfaces

• “For a typical component, we have reduced the drilling time from two days to an hour” Gerry Hart, CADCAM Manager, Rojac

5-axis Drilling

Benefits of Continuous 5 axis machining

• Ideal for profiling parts • Ideal for machining deep cores and cavities • Short cutters give increased accuracy and higher

quality surface finish • Allows for machining with the flank or bottom of the

tool • Can be used with a full range of tool types • Full gouge protection • Can be used with models in STL format (with the

exception of profiling)

5-axis machining of bottle

Machining of V Block

5 Axis engraving

Machining of scanned data

•Can be used with models in STLformat

Turbine blades

Sand casting

5 Axis Machining from solid

• Trend to machine complete from block– Shorter product life

cycles– Shorter development

lead times– Smaller production

runs• Replaces castings or

forgings

5 Axis simulation and verification

4-axis machining• Job rotates around the

X axis with linear, spiral or circular machining strategies along Y and Z axes.