Use opFillet for a sketch?

sören_svensson

Hi,

I'm trying to use opFillet to fillet corners in a sketch but I'm only getting not really helpful errors like FILLET_FAIL_SMOOTH and FILLET_SELECT_EDGES.

Here's a current snippet (I've tried many variants)

    var outerSketch = newSketch(context, id + "outerSketch", {

            "sketchPlane" : qCreatedBy(makeId("Top"), EntityType.FACE)

        });

    var outerPoints = [

        vector(rightX, (angleCenterX + rightX) * tan(upperAngle)),

        ur,

        ul,

        vector(leftX, (angleCenterX + leftX) * tan(upperAngle))

        

    ];

    for(var i = 0; i < size(outerPoints); i += 1)

    {

        skLineSegment(outerSketch, "outer_line" ~ i,

        { "start" : outerPoints[i],

          "end" : outerPoints[(i + 1) % size(outerPoints)]

        });

    }

    

    // close sketch for outer race

    skSolve(outerSketch);

    var edges = [];

    edges = append(edges, qContainsPoint(qCreatedBy(id + "outer_line0", EntityType.EDGE), vector(rightX, definition.outer / 2, 0 * millimeter)));

    edges = append(edges, qContainsPoint(qCreatedBy(id + "outer_line1", EntityType.EDGE), vector(rightX, definition.outer / 2, 0 * millimeter)));

    debug(context, edges);

    opFillet(context, id + "fillet1", {

            "entities" : qUnion(edges),

            "radius" : 0.2 * millimeter

    });

Every example I've found uses opFillet on bodies and not sketches but there's a fillet command in the sketch UI so I assume it should work.

ilya_baran

Unfortunately, the sketch fillet (and other sketch commands like trim, offset, etc.) are very different than features and are not accessible through FeatureScript at this time.  I would suggest filleting the relevant edges once the sketch is turned into a solid.

ilya_baran

Unfortunately, the sketch fillet (and other sketch commands like trim, offset, etc.) are very different than features and are not accessible through FeatureScript at this time.  I would suggest filleting the relevant edges once the sketch is turned into a solid.

sören_svensson

Thanks for the answer!

Aaron_Hoover

Any chance the availability of opFillet in sketches has changed in the last couple years?

Jake_Rosenfeld

@Aaron_Hoover

The advice Ilya gives is still valid.  The "fillet" sketch tool actually alters the sketch code to push back the neighboring edges and insert an arc between them (with skArc).  Filleting after a thicken or extrude is a good option, as well as doing the calculations for the endpoint locations for skArc.  If you share your specific problem I may be able to give more specific advice.

Aaron_Hoover

@Jake_Rosenfeld

This is super helpful. I'm currently trying to create a FeatureScript to create a dovetail joint like in this "Halved Dovetail Corner" joint: https://cad.onshape.com/documents/f22179460c63ac8d20c705e1/w/411adc4bdfc59835797812ed/e/dd2666a629e40f017ce24997. 

In fact, there are many joints in the 50 digital joints collection that could make use of a "2D" fillet that gets extruded and Boolean'd (unions and subtractions) appropriately. So, I'm seeking a solution that makes this code as simple (and reusable) as possible.

Do you have any examples of using the skArc to create fillets? It seems arduous to have to compute endpoint locations for straight segments to ensure tangency (for example). 

NeilCooke

@Aaron_Hoover you don’t need to calculate them precisely, you can add constraints and skSolve. See the Spur Gear example. https://cad.onshape.com/documents/5742c8cde4b06c68b362d748/w/b493e0cb681bbf9497d9f4b3/e/01a666571e625f8b819fd75b

ilya_baran

I still think a solid fillet is likely to be easier...