Passing Flat Pattern Geometry from a CAD System to Automatic Machining and Press Brake Programming

Transcription

1 Passing Flat Pattern Geometry from a CAD System to Automatic Machining and Press Brake Programming For specific information on how to interface from each of the main CAD systems on the market for sheet metal design see section 2 of this document. The system offers almost total integration with AutoPOL (Fleming Software is a reseller for this product). API interfaces from Solid Works, Solid Edge, Pro-E and Inventor are under development. 1. General overview of the format required Automatic Machining and Press Brake Programming accept flat pattern geometry in two formats, DXF or SPAN data. Span data is a very compact way of describing 2D geometry, but few modern CAD systems support geometry output in this format, so the normal way of transferring geometric data is in DXF format. If Press Brake Programming is in use the system requires both flat pattern part geometry (outer contour and apertures), and bend information, including: 1) Bend centre lines 2) Bend inside angles 3) Bend inside radii (bend specific or global for all bends on the part) 4) Bend directions (up/down) 5) K-Factors (bend specific or global for all bends on the part) The system also needs to know: 1) Part name 2) Material type (a two character code, e.g. MS for mild steel) 3) Thickness If Automatic Machining is in use but not Press Brake Programming, the bend information is desirable but not essential. Any of the above information can be added to the part or modified after loading the information available to Automatic Machining or Press Brake Programming, but the better the quality and quantity of the information passed directly inside the DXF file the easier the system will be to use. Other information in the DXF file is not relevant and will be ignored (drawing frame, dimensions etc.). The flat pattern part geometry should ideally be at FULL SCALE in MM units. The optimum format is as follows: 1) Part flat pattern geometry and apertures are passed in CONTINUOUS line type in a layer separate from other drawing information, ideally called CONTOUR. 2) Bend centre lines are passed in CENTER line type in a layer named BEND-LINES. 3) Part name, material type and thickness information may be passed in one of two ways: a. Text strings in the DXF file using the EXACT format specified below (same spacing and all in lower case the data is enclosed in square brackets). This text can be HIDDEN, or defined in a block that is not inserted if required so that it is invisible to the user in the CAD system, as long as it appears as a text strings in the DXF file. partname : [] thickness : [] material : [] Optionally the thickness line can also include global bend radius and K-factor settings, or these can be specified associated with each bend line: thickness : [] Radius : [] K-Factor = []

2 b. Alternatively this information can be communicated using the layer name for the flat pattern geometry: PPPP_MM_TTT Where i. PPPP is the part name (a text string) ii. MM is a two character material type code (upper case) iii. TTT is the material thickness expressed in unit of hundredths of a millimeter (250 is 2.5mm thick) (decimal point is not a valid character in a DXF layername). So a layer name of: ABC12345_SS_120 Would be interpreted as part name ABC12345, stainless steel, 1.2mm thick. 4) The bend internal angle, bend radius, and K-factor can be transferred as text strings in the layer name BEND_ANGLES. The positioning point for the text should be close to the mid-point of the bend line to which the information relates. For example: -90 R=1 K=0.75 would signal a 90 degree DOWN bend with inside bend radius of 1.0 and a K-factor of ) The bend direction can be communicated either using the sign of the bend angle Positive for UP and negative for DOWN, or using the bend line COLOUR, GREEN (DXF colour number 3) for UP bends, and MAGENTA (DXF colour number 6) for DOWN bends. The next section covers each major CAD system currently in use for Sheet Metal design and flat pattern development, and how to get the output as close as possible to the optimum format described above.

3 2. How to Extract the Flat Pattern Geometry from Your CAD System 2.1 AutoPOL AutoPOL is a 3D sheet metal design and flat pattern development system developed by FCC Software AB in Sweden. Fleming Software is a re-seller for this product. After creating a part in 3D, or importing a solid model of a sheet metal component in STEP or SAT format, switch to 2D (flat pattern development mode).

4 Export the file to DXF.

5 AutoPOL, since late 2003, includes a DXF export template called Fleming Software. This is pre-configured to create DXF files that will communicate seamlessly with Automatic Machining and Press Brake Programming. Just select Fleming Software from the User defined settings menu. Alternatively, or for older AutoPOL versions, you can create a new template for export to Automatic Machining or Press Brake Programming. Here we have created one called AutomaticMachining. When you then export the DXF file you may select this template to get the exact output required for a seamless interface from AutoPOL to Automatic Machining or Press Brake Programming. Use the Save button, specify the new template name and click Create New to create the new template. Then click Line & Text Settings to setup details of the new template.

6 Copy and paste the following text strings into the relevant boxes so you get the format exactly right: 1) Contour lines,text: thickness : [<T>] Radius : [<R>] K-Factor = [<K>] 2) Bend angle text, Up: <> R=<R> K=<K> 3) Bend angle text, Down: -<> R=<R> K=<K> Also ensure the Internal angle is checked, and layer names, precision, line types and colour are exactly as specified. The only information not available in AutoPOL is the material type, which you can specify in Automatic Machining or Press Brake Programming after loading part geometry exported from AutoPOL using this template. Otherwise the interface is seamless.

7 2.2 Solid Works An API interface to integrate Automatic Machining and Press Brake Programming with Solid Works 2004 is currently under development. Contact Fleming Software for further details: Tel:

8 2.3 Solid Edge An API interface to integrate Automatic Machining and Press Brake Programming with Solid Edge is currently under development. Contact Fleming Software for further details: Tel:

9 2.4 Pro-E An API interface to integrate Automatic Machining and Press Brake Programming with Pro-E is currently under development. Contact Fleming Software for further details: Tel:

10 2.5 Inventor An API interface to integrate Automatic Machining and Press Brake Programming with Inventor is currently under development. Contact Fleming Software for further details: Tel:

11 2.6 AutoCAD or other 2D CAD system See section 1 for details of the format required.