Feature Script: Roll Form Die - How to subtract transformed parts in a loop?

ludwig_haas

Hi Onshapers,

In essence, I am trying to create a roll form die from an imported part.

I have identified two ways of doing this:

Way #1: "Rotate Part around roll"

In this case, I import the part, drop a MateConnector on its center and create a cylinder as a "roll" above it. The center of the cylinder is aligned with the center of the part, but moved up, by the radius R.

With the following code I rotate the part around the MC while moving its tangential point accordingly and create a copy for every step.

This yields me a number of parts (from -90° to +90° it is 180) that I then have to subtract from the cylinder.

My question is: How do I incorporate the opboolean to subtract every new generated part from the cylinder.

(Doing this by hand takes some time and some parts fail to subtract)

&nbsp;&nbsp;&nbsp;    precondition<br>        <br>    <br>    {<br>        annotation { "Name" : "My Query", "Filter" : EntityType.BODY, "MaxNumberOfPicks" : 1 }<br>        definition.Part is Query;<br>        <br>        annotation { "Name" : "Mate Connector", "Filter" : BodyType.MATE_CONNECTOR, "MaxNumberOfPicks" : 1 }<br>        definition.mc is Query;<br>         <br>        annotation { "Werkstuck2" : "My Query", "Filter" : EntityType.BODY, "MaxNumberOfPicks" : 1 }<br>        definition.cyl is Query;    <br>    <br>    }<br>    {<br>        <br>        const parentId = id + "tools";<br>        const parentId2 = id + "boolean";<br>        var i = 0;<br>        var angle = -90;<br>        for (var i = 1; i < 180; i += 1)<br>        {<br>        <br>        var mc = evMateConnector(context, { "mateConnector" : definition.mc });<br><br>        var rotation = rotationAround(line(mc.origin, mc.xAxis), angle * degree);<br>        <br>        var verschieben = transform(vector((5.31496*sin(angle * degree))+((angle/180*5.31496*PI)*-cos(angle * degree)), 0, (5.31496*-cos(angle * degree)+5.31496)+((angle/180*5.31496*PI)*-sin(angle * degree))) * inch);<br>        <br>                <br>        opPattern(context, parentId + toString(i), { "entities" : definition.Part,<br>                                 "transforms" : [verschieben * rotation],<br>                                 "instanceNames" : ["1"],<br>                                 notFoundErrorKey("entities") : ErrorStringEnum.COPY_SELECT_PARTS });   <br>        angle = angle + 1;<br>        <br><br>        opBoolean(context, parentId2 + toString(i), {<br>                "tools" : definition.Part,<br>                "targets" : definition.cyl,<br>                "operationType" : BooleanOperationType.SUBTRACTION,<br>                "keepTools": true<br>        });<br>        <br>        }<br>                             <br>    });<br>

Way #2: "Rotate and move Roll on tool"

In this scenario I am placing the cylinder on the very left of the part and then perform a rotational and translational movement to the roll. (The slot was just to track if the rotation was correct).

Again I am struggeling to incorpoorate the boolean subtraction into my loop.

precondition<br>        <br>    <br>    {<br>       annotation { "Tool" : "My Query", "Filter" : EntityType.BODY, "MaxNumberOfPicks" : 1 }<br>        definition.Part is Query;<br>        <br>        annotation { "Roll" : "My Query", "Filter" : EntityType.BODY, "MaxNumberOfPicks" : 1 }<br>        definition.cyl is Query;<br>        <br>        <br>        annotation { "Name" : "Cylinder", "Filter" : EntityType.FACE && GeometryType.CYLINDER, "MaxNumberOfPicks" : 1 }<br>        definition.Constant is Query;<br>            <br>    <br>    }<br>    {<br>        const parentId = id + "tools";<br>        const parentId2 = id + "tools2";<br>        const parentId3 = id + "boolean";<br>        var i = 0;<br>        var angle = 90;<br>        //for (var i = 1; i < 5; i += 1)<br>        //{<br>        <br>        var axis = evAxis(context, { "axis" : definition.Constant });<br><br>        var rotation = rotationAround(axis, angle * degree);<br>        <br>        var move = transform(vector(((angle/360)*PI*2*5.158241), 0, 0) * inch);<br>        <br>                             <br>        opTransform(context, parentId + toString(i), {<br>                "bodies" : qOwnerBody(definition.cyl),<br>                "transform" : move * rotation <br>        });<br>        <br>        opTransform(context, parentId2 + toString(i), {<br>        "bodies" : qOwnerBody(definition.Constant),<br>        "transform" : transform(vector(((angle/360)*PI*2*5.158241), 0, 0) * inch)<br>        });<br>        <br>                          <br>        opBoolean(context, parentId3 + toString(i), {<br>                "tools" : definition.Part,<br>                "targets" : qOwnerBody(definition.cyl),<br>                "operationType" : BooleanOperationType.SUBTRACTION,<br>                "keepTools": true<br>        });<br>        <br>        //angle = angle + 1;<br>        //}                       <br>    });

Follow up question: The Roll needs to be imported into a simulation tool. If the boolean leaves me with a rough surface, I might need to smoothen it. Is there a way to do that?

Thanks in advance

Ludwig

konstantin_shiriazdanov

The Envelope feature is not very perfomant, so the regen time for 50 cross sections per 50 points in each is about 60 seconds and it is the best I could do with the functions avaliable.

RotTrace creates an array of tool body instances in their intermediate positions during the motion relatively to workpiece body.

Envelope feature detects the points of envelope surface using raycast function.

If your tool body has any symmetry I would absolutely reccomend to use a minimal nontrivial part of this body and then creating the pattern of resulting envelope geometry

konstantin_shiriazdanov

Surprisingly, I was resently asked about pretty similar example

https://cad.onshape.com/documents/8debf48a92e4eff2ad42217d/w/a8176d7619e9aff1cac8d3e6/e/4a3af5cbdf6a64e5fdb2e136

Jacob_Corder

konstantin_shiriazdanov said:

Surprisingly, I was resently asked about pretty similar example

https://cad.onshape.com/documents/8debf48a92e4eff2ad42217d/w/a8176d7619e9aff1cac8d3e6/e/4a3af5cbdf6a64e5fdb2e136

@konstantin_shiriazdanov
That is really amazing!!. Perfect surface quality also. 

ludwig_haas

@konstantin_shiriazdanov

Thanks for the Imput, that looks great!

So RotTrace performans a rotation and movement around the center of the cylinder, while Envelope 3D combines the surface of the parts to one part.

Does this result in a "bend" of the original surface?

I am having some performance issues when using small Steps in RotTrace (1 mm) and many Points in Envelope 3D (>30). Is there any tips on this?

Also if my part has two bulges (like shown in the picture below):

- would I perform RotTrace and Envelope 3D once on both bulges

- or move the bulges exactly below the centerpoint of the circle, perform both scripts on one bulge and then rotate and move they cylinder ove the next bulge?

konstantin_shiriazdanov

The Envelope feature is not very perfomant, so the regen time for 50 cross sections per 50 points in each is about 60 seconds and it is the best I could do with the functions avaliable.

RotTrace creates an array of tool body instances in their intermediate positions during the motion relatively to workpiece body.

Envelope feature detects the points of envelope surface using raycast function.

If your tool body has any symmetry I would absolutely reccomend to use a minimal nontrivial part of this body and then creating the pattern of resulting envelope geometry