AutoCAD ETO

Inventor Engineer-to-Order (ETO) Series is a product that allows the automation of repeatable designs. ETO captures engineering logic and taking care of the code typically required for configuring, placing and creating parts and assemblies in Inventor.

A little known fact is that ETO can also be used with AutoCAD much in the same way that it can be used with Inventor.

In this simplified example I have created an ETO model called "MarksDesign". "MarksDesign" is a model for laying out bolt configurations. It allows for the specification of bolt layout and type and provides some simple design attribution.

In AutoCAD, ETO adds an additional panel which displays information about the loaded ETO design model. Currently as shown below the design is using "M10" bolts, has 2 bolts per array and has two arrays.

By adjusting the parameters in the design we can see that the AutoCAD design will be updated.

We set the array quantity to three and the number of bolts in an array to four.

And set the bolt type to "M4", note the drop down list for selecting values.

After clicking "Ok" we can see that the drawing and annotations have been updated.

An ETO design is captured in a language called Intent, it looks similar to Visual Basic and shares some syntax, but that's where the similarities end.

ETO's Intent language is all about capturing the rules that create a design. When you look at Intent code you don't see the complexities of dealing with AutoCAD entities in the same way that you would with .Net, VBA or AutoLisp.

The code that is behind this demo ETO Design is as follows:

 

Design MarksDesign : AcDrawingDocument my_designs_Root    
    
    <%%Choices("M10,M4")> _
    Parameter Rule boltType  As String  = "M10"
    Parameter Rule arrayQuantity  As Integer  = 2
    Parameter Rule boltsInArray  As Integer  = 2
    Uncached Rule totalBolts As Integer = arrayQuantity * boltsInArray
    Child boltArray As :BoltArray, Quantity = arrayQuantity
        basePoint = Point(0,500 * (child.index - 1),0)         
    End Child
    
    Child BoltArrayDimension As :LinearDimension        
        fromPoint = nth(1,boltArray).basePoint 
        toPoint = nth(arrayQuantity,boltArray).topPoint 
        location = Point(-50,0,0)
        dimtype = :Vertical
        charHeight = 40
    End Child    
    
    Child TotalBoltLeader As :TextLeader
        charHeight = 30.0
        Text = "Total Bolts: " + stringValue(totalBolts) + "x  " + _
        boltType
        location = nth(1,boltArray).basePoint + Vector(300,200,0)
        toPoint =  nth(arrayQuantity,boltArray).topPoint 
    End Child
End Design

Design BoltArray : my_designs_Root LightweightPart
    Parameter Rule basePoint As Point  = Point(0,0,0)
    Parameter Rule topPoint As Point  = basePoint + _
    Vector(0,50 * (length(hBolt) - 1),0)
    Lookup Rule boltType  As String  = "M3"
    Lookup Rule boltsInArray = 5
    Child hBolt As :Insert, Quantity = boltsInArray
        blockName = :HexBolt
        libraryFile = "G:\Dynamic Blocks\Mechanical - Metric.dwg"
        sourceName = "Hex Socket Bolt (Side) - Metric"
        reload? = False        
        origin = Vector(0,50 * (child.index - 1),0) + basePoint
        dynamicProperties = {"Size", boltType}
    End Child
End Design
			

 

At first glance the Intent code may appear daunting, but on closer inspection you'll see that all it is doing is creating properties that the user can interact with, creating arrays (groups) of elements in the design, and positioning where things should appear in the design.

To achieve something similar in a maintainable, reusable, rules orientated way in another language would require hundreds of lines of more code. This structured rules oriented way of designing saves a few man hours when creating a demo but is multiplied exponentially on a real project.

This is only the first snowflake on the tip of the iceberg of what ETO can do, for some online samples and videos check out: http://etosamples.autodesk.com/

Comments

[Shardy]

Great article is there any chance I can take it and copy it onto my own blog