Win more NC Programming projects with fast, accurate estimation

Win Contract Bids by minimizing machine runtime estimations, quickly and accurately in CATIA V5.

You have to quote a 100 part program in 2 weeks. This is a time-consuming effort with no guarantee you will win the job. Do you take the time to make sure you are competitive and accurate, or do you add extra ‘padding’ to ensure you won’t lose money? Will that padding cost you the job? These are the day to day struggles in maintaining that balance.

Material cost is a straight forward calculation, but estimating machine run times for these parts is a large part of the equation. By leveraging a few tools that already exist in CATIA, you can estimate your programming time on these parts in a fraction of the time as compared to tribal knowledge and manual calculations.

Process Specifics
With the use of knowledge based machining practices one can minimize NC Programming time dramatically. The intention is not to program the part to run in reality, but rather to estimate realistic runtimes on the machine to accurately quote individual parts. With the use of Process Catalogs, one can quickly build an NC Program on any part to derive a machine run time. Process Catalogs is a methodology that CATIA V5 uses to capture NC Programming knowledge, techniques, machine operation specifics, sequence of machining operations, and more.

Once a series of machining operations are created in CATIA V5, one can run a simple script, which is included with every CATIA V5 installation, to generate a total run time for the programmed part. Of course some of the specifics that are captured with Process Catalogs include speeds and feeds, machine rapid values, and max machining feed-rate of the machine tool. Therefore, when CATIA V5 uses the above mentioned script, the total runtime value is accurate.
Of course, if interested in Knowledge Based Machining, one must “populate” CATIA V5 with the machining specifics required to use this technology. Three fundamental approaches are used to build Process Catalogs within CATIA.

Prismatic Machining

runtime 1

If the parts are more Prismatic in nature, for example, a lot of axial type features, the process catalog can be highly automated to allow CATIA to query a part and then assign machining operations based upon the type of geometrical features that are discovered. For example, CATIA discovers some .500” tapped holes. First off, CATIA will make a machining pattern automatically of the hole locations for this feature. The machining operations defined to machine this feature could be; spot drill each feature hole location, drill each hole to a specific diameter (probably a .469” diameter), then tap the hole with a .500” diameter tap. So for this one particular feature, CATIA has applied automatically three different machining operations with all the necessary settings to correctly machine this geometry.

Surface Machining

Runtime 2

If the parts are more Surface Machined geometries, the process catalog development can still be very automated, basically applying a series of operations in a specific sequence to completely machine the part, even including reworking operations to machine smaller areas of geometry the larger end mills cannot reach. For example; when I machine surfaced parts I will start with a Roughing Operation to remove as much material as possible. The next operation will actually rework the roughing to continue breaking the part down to manageable geometries the finishing tools can start addressing. A series of finishing operations will occur to machine the part to necessary finish requirements. And lastly, rework some of the finishing operations that occurred with larger finish end mills that will probably leave unfinished areas on the part. You guessed it, CATIA will automatically calculate the rework areas’ where remaining material exists, and then apply rework machining operations to machine the remaining materials with the appropriate smaller end mills.

5-Axis Machining

Runtime 3

Often times with very complex 5 Axis geometries, one will need more control and have to make NC Programming decisions on the fly to address 5 Axis control. So a combination of automated process catalogs can be introduced to complete 75% to 80% of the programming, and then use some individualized process catalogs for 5 axis operations to add to the part program to completely finish the part. The individualized process catalogs will have individual machining operations completely defined except for geometry. So the NC Programmer simply adds the machining operations to the program, selects the appropriate geometry and computes machining activity. Still very quick and precise programming.

Machining Time Estimation

Once all of the programming activity has been generated, one simply applies a script to calculate the total machining time for the part program. This script runs very quickly; only a matter of seconds to provide you with the valuable machine runtime information.

Runtime 4

Runtime 5

With this process, it is feasible to program a lot of parts in a short amount of time and have confidence the “machine runtime” value will be in the 90 percentile of accuracy.

Inceptra has developed a set of pre-defined Process Catalogs and Tooling to speed up the implementation of this solution.

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