Create sketch in middle of part

Lee_Hesketh

Hi all. I have a script where the user selects a face, then using qConvexConnectedFaces twice to select the ends. I have then found the midpoint of each of those faces and used them to find the midpoint of the part. What I need to do is create a plane at that point parallel to the end faces and then create a sketch. How could I do this?
Also, how could I implement the midplane feature from the plane command?
Thanks
Lee Hesketh

jakeramsley

Hi Lee_Hesketh,

To create a plane, you can use the constructor that takes:

plane (origin is Vector, normal is Vector) returns Plane

The origin of your plane is going to be the mid-point that you calculated and the vector should be the normal of the plane to make them parallel.  Such that:

var planeDef = plane(midPoint, plane1.normal);

From here, I would make an opPlane off of this:

<div>opPlane(context, id + "plane", {
  "plane" : planeDef,
  "width" : 6 * inch,
  "height" : 6 * inch
});</div><div></div>

Then you want to make a sketch based on this plane

var mySketch = newSketch(context, id + "sketch1", {<br><span style="font-family: Flama, sans-serif;">&nbsp; "sketchPlane" : qCreatedBy(id + "plane", EntityType.FACE)<br></span><span style="font-family: Flama, sans-serif;">});</span>

Since you already have the mid-points, I would use the cPlane command with the cplaneType set to CPlaneType.MID_PLANE.  

cPlane(context, id, { <br>&nbsp; "entities" : [query of both mid-points], &nbsp;<br>&nbsp; "cplaneType" : CPlaneType.MID_PLANE, <br>&nbsp; "flipAlignment" : false, <br>&nbsp; "width" : 6.0 * inch, <br>&nbsp; "height" : 6.0 * inch <br>});

jakeramsley

Hi Lee_Hesketh,

To create a plane, you can use the constructor that takes:

plane (origin is Vector, normal is Vector) returns Plane

The origin of your plane is going to be the mid-point that you calculated and the vector should be the normal of the plane to make them parallel.  Such that:

var planeDef = plane(midPoint, plane1.normal);

From here, I would make an opPlane off of this:

<div>opPlane(context, id + "plane", {
  "plane" : planeDef,
  "width" : 6 * inch,
  "height" : 6 * inch
});</div><div></div>

Then you want to make a sketch based on this plane

var mySketch = newSketch(context, id + "sketch1", {<br><span style="font-family: Flama, sans-serif;">&nbsp; "sketchPlane" : qCreatedBy(id + "plane", EntityType.FACE)<br></span><span style="font-family: Flama, sans-serif;">});</span>

Since you already have the mid-points, I would use the cPlane command with the cplaneType set to CPlaneType.MID_PLANE.  

cPlane(context, id, { <br>&nbsp; "entities" : [query of both mid-points], &nbsp;<br>&nbsp; "cplaneType" : CPlaneType.MID_PLANE, <br>&nbsp; "flipAlignment" : false, <br>&nbsp; "width" : 6.0 * inch, <br>&nbsp; "height" : 6.0 * inch <br>});

ilya_baran

Also, keep in mind that in FS you don't need to actually create a construction plane to sketch on -- you can pass a plane directly to newSketchOnPlane (that will, in fact, likely make things easier because then the coordinate system of the sketch is the coordinate system of the plane).  See https://cad.onshape.com/FsDoc/library.html#newSketchOnPlane-Context-Id-map