kojin mould case study

Institute of Manufacturing Technology

Manufacturing Information Technology Division

Kojin Mould Case Kojin Mould Case StudyStudyLiu PeilingCAPT Group

NC Verification



AgendaAgenda Introduction NC Program Errors Requirements for Kojin Mould Commercial Solutions Our Approach

– “WhatYouSee is WhatYouCut” NC Verification Samples in

Practice



Our Client --- Kojin MouldOur Client --- Kojin Mould

Design and manufacture plastic molds. A wholly owned subsidiary of Omni

Industries Limited. Over 60 employees including

– 3 mold designers– 7 NC programmers using 4 seats UG CAM– One seat VERICUT 4.0 for NC simulation



What is NC Verification?What is NC Verification?

Check NC Code Safety

– No cutter clash or damage– No cut clamps or fixtures

Quality – No undercut or gouge– All appropriate stock

removed – Surface finish and tolerance– Air cut

(33C1B-DIA 63-R6.0)(18-MAR-00)G90G0X0Y0Z100.G05P10000G00X-82.898Y14.76Z3.Z2.217G01Z-.783F1500X-52.898X-44.215Y-12.904...



NC Program Errors 1NC Program Errors 1

The Low Quality of The Low Quality of SurfacesSurfaces The surface deformation.

– Example: data exchange problem. The surface tolerances are too low.

– Example: 0.1mm. The geometry data defects.

– Example: there are gaps between surfaces.




Unstable CAM AlgorithmsUnstable CAM Algorithms Path planning is a very difficult

task. There is no exact offset solution

for free form curves and surfaces The toolpath sampling method

varies quite differently.



Toolpath planning errors, too many jumps Un-uniform water level cut

plungezigzag

Offset calculation errors Water level toolpath become zigzag



10 meters arc

10 meters arc

10 meters arc


The Post-Processor BugsThe Post-Processor Bugs




The Human ErrorsThe Human Errors The patching up of surfaces. Plan machining process. Wrong part face, check face and

boundary choice. Wrong machining set-up. Wrong cutting parameters



Why They Need NC Verification? 1Why They Need NC Verification? 1

The 3D CAM MigrationThe 3D CAM Migration The 3D CAM requires more NC

programs and programmer than 2D CAM.– NC program exceeds one million

lines– One designer needs two NC

programmers– Using sub-contractor for NC

programming




High Speed MachiningHigh Speed Machining The fast NC verification of huge tool path

– The HSM requires over half million blocks of G/M code. The simulation process must be quicker than test cut.

Dynamic simulation of the cutting process– The HSM feed rate could be ten meter per minute. The cutter

will break under uneven load.

Automatic check over-cutting and gauging– Visual check is time consuming and unreliable.




Outsourcing Outsourcing ManufacturingManufacturing

Product designer - HP Contract manufacturer - Omni Industry

Mold maker - Kojin MouldMold designer - Super SolidCAM programmer - SINCAMElectrode maker - Atech

Outsourcing NC programs



Requirements from Kojin Requirements from Kojin MoldMold Cut SafeCut Safe

– Instant check for overcut & gougingInstant check for overcut & gouging– Quick check for High Speed

Machining Cut better

– Surface roughness simulation Cut faster

– Air cut removal



Commercial SolutionsCommercial Solutions Animated pictures made of pixels Rough View

angle dependent

Machining load ?

zoomed pixels



Problem with view-angle dependant:Strait edges become zigzag after rotation



Our ApproachOur Approach 1 1

WYSWYC WYSWYC what you see is what you cut

machine table

block

roughing

finishing



smooth vertical walls along curves

Our Approach 2 Our Approach 2

Rotate & Zoom to See Rotate & Zoom to See DetailDetail



Overcut error

toolpath

car model

Our Approach 3Our Approach 3

Instant Check for Overcut Instant Check for Overcut




FasterFaster Batch ProcessingBatch Processing Traditional simulation does it step by step

Read one block of NC code Parsing to check grammar errors Generating sweeping volume Subtract this sweeping volume from Z buffer Update display

There is no grammar error for CAM NC! We can read and simulate the whole NC

file ten times faster than traditional simulation.




Interactive Toolpath Interactive Toolpath ControlControl

The NC data text file can be turned off



Our ApproachOur Approach 6 6

In-process Stock In-process Stock is a must for next is a must for next step Cutting Plan. step Cutting Plan.

roughing

Middle roughing

Semi finishing

Finishing

We can define We can define intermediate intermediate model as a set model as a set of NC toolpath, of NC toolpath, cutter and initial cutter and initial stock. We only stock. We only need to store need to store these three these three parameters in a parameters in a database. We database. We cancan regenerate regenerate the the intermediate intermediate model anytime model anytime using a NC using a NC simulator. simulator.



Out Approach 7Out Approach 7

Output Process Data SheetOutput Process Data Sheet



Our Approach 8Our Approach 8 GUI CustomizationGUI CustomizationView toolbarToolpath control stock

Multiple view

inspection



Implementation in Kojin Implementation in Kojin MouldMould One seat for CAD/CAM department– with direct UG CLSF interface & STL import– In-process stock to help CAM programmer– Quick process sheet and post-processing

One seat for CAM out-sourcing– G/M code simulation for different CAM

system– Automatic check and documentation

One seat for shop floor machinists– NC tool path and setup preview



How to help NC programmer?How to help NC programmer?

Cut Mould InsertCut Mould Insert



How to Help NC How to Help NC Programmer?Programmer?

Plane

Curve surface

Plane

Pocket

EDM

Slot



How to help NC programmer? 1 How to help NC programmer? 1

Planer Mill to Cut Plane Planer Mill to Cut Plane AreaArea

planer area



planer area




Rough and Finish the Rough and Finish the SurfacesSurfaces

Cut curved surface

Fill this pocket




Finish the Small DetailsFinish the Small DetailsLocal mill for small area



How to help NC programmer? 4How to help NC programmer? 4

Roughing Pocket for EDMRoughing Pocket for EDM

Clear pocket for EDM



The cutter cannot cut to the designed part shape due to the limitation of cutter size. The EDM process will clean the remaining stock.



Detail zoom in



Cellar Phone Mould Core Cellar Phone Mould Core InsertInsert

Plane

Flush face

Curved surface

EDM



Fixed Contour for FinishingFixed Contour for Finishing



Over cut? Over cut?

Over cut?



Over cut?

Over cut?



Over cut ?



Over cut 0.02?



Over cut >0.02?



Feedback from Kojin MoldFeedback from Kojin Mold As of early 1999... At present this software not only able to create

the model by the program data , it also : provide the lowest Z value checking of Z level from the model import the actual model and compare both parts together edit of tool path and re-post the program direct read in the CLS files from UG able to zoom in/out with good display able to have dynamic rotation

Lastly we would like to express our appreciation...



Thank Thank YouYouLiu PeilingLiu Peiling

Tel: (65) 7938356Tel: (65) [email protected]@gintic.gov.sg

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