Extrusion Editing

mike_pearson

Hello,
I'm new to onshape and have little experience in CAD in general. I've been going through tutorials and am getting pretty good at sketching prior to extruding. I have had successes extruding basic geometries. When the geometry is not straight forward, I hit a wall. I've been struggling with a part all day so I decided to follow this video and make the same part as it, in hopes it would click.

I seem to have different behavior though than the environment on the video. Everything is fine up to 1:38 when he select the yellow intersecting point. Mine allows me to select it, but it disappears as soon as I hit the line tool. Is there a different setting I don't have?

Also, if interested, I've attached the fixture block I've been practicing with. I can extrude everything except the angled portion. I can't figure that one out.

Thank you for taking the time,
Mike

cadmando

If you have constrained the circle for your hole to the origin you need to draw the triangle to extrude on the front plane and use the option Symmetric and used the extrude distance of 3.5 for both options. If this does not help share the document with me and I will take a look.

andrew_troup

@mike_pearson
In regard to your first question: Like you, when I follow the procedure in the video exactly, the inferred point (at the top left corner of the flat face on the near side of the solid body) does not remain active when I select the line tool. I assume the video was made with a different (perhaps early, or future, or never "pushed") version of Onshape. It's a fast evolving tool, and it can be difficult to keep track of the details of operations.

As far as I know, inferences (which automatically capture a constraint, and whose indicator is an orange dotted line) can only be made to solid vertices which lie on the sketch plane, or to the sketch origin, which is a projection onto the sketch plane of the model origin.
Inferences cannot be made to other sketches, even if they share the same sketch plane as the active sketch.
Hopefully someone more knowledgeable will correct me if I have this wrong.

In the situation shown in the video, it does not matter, because you only need to provide a vertical construction line through the origin;  the length and endpoint locations are immaterial, provided you click on the LINE when adding the dimension to the apex of your triangle.

If you were in a situation where you needed to infer to the corner of that face, there are a couple of options: the most straightforward is to place a sketch point somewhere in white space (so it won't accidentally infer an unwanted constraint) and then select both the sketch point and the corner point, then choose "Coincident". Now you can infer from that sketch point, and the point (like construction geometry) will not affect any features created from that sketch, like extrude or revolve.

cadmando

If you have constrained the circle for your hole to the origin you need to draw the triangle to extrude on the front plane and use the option Symmetric and used the extrude distance of 3.5 for both options. If this does not help share the document with me and I will take a look.

andrew_troup

@mike_pearson
In regard to your first question: Like you, when I follow the procedure in the video exactly, the inferred point (at the top left corner of the flat face on the near side of the solid body) does not remain active when I select the line tool. I assume the video was made with a different (perhaps early, or future, or never "pushed") version of Onshape. It's a fast evolving tool, and it can be difficult to keep track of the details of operations.

As far as I know, inferences (which automatically capture a constraint, and whose indicator is an orange dotted line) can only be made to solid vertices which lie on the sketch plane, or to the sketch origin, which is a projection onto the sketch plane of the model origin.
Inferences cannot be made to other sketches, even if they share the same sketch plane as the active sketch.
Hopefully someone more knowledgeable will correct me if I have this wrong.

In the situation shown in the video, it does not matter, because you only need to provide a vertical construction line through the origin;  the length and endpoint locations are immaterial, provided you click on the LINE when adding the dimension to the apex of your triangle.

If you were in a situation where you needed to infer to the corner of that face, there are a couple of options: the most straightforward is to place a sketch point somewhere in white space (so it won't accidentally infer an unwanted constraint) and then select both the sketch point and the corner point, then choose "Coincident". Now you can infer from that sketch point, and the point (like construction geometry) will not affect any features created from that sketch, like extrude or revolve.

mike_pearson

Thank you both. I got both completed.