So, our reseller is pushing a SolidProfessor Skills Analyzer contest. There are 3 levels (basic, advanced and expert). For giggles I took the Basic exam and was shocked to see that I supposedly missed question 1 in the sketching section:
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My answer is 100% correct. You cannot know that X and Y are aligned. Exhibit A:
Show all sketch constrains.
I don’t know how you did it to get an angle in your image, but the construction line linking the two is what should tell you that they are aligned.
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The one from the contest is missing the constraints that you are showing in yours.
If the constraints are showing, or this were on a technical drawing with ASME requirements, then yes, I would say that you can tell that they are aligned.
But on a sketch where you can’t see the constraints and can only look at it. JSculley is absolutely correct.
The constraints are not shown in the image because it’s an exam, it’s made to test your knowledge. When you draw a line with your pencil on a sheet of paper using a ruler, do you see a mate appear? I was thought in school that a line that looks straight is straight unless identified otherwise.
Assuming it was a multiple choice question I’d be curious to see the offered answers.
I’d agree you can’t know but it would be an extremely safe assumption that in the absence of any other dimensions or geometry to the contrary, the construction line is coincident and parallel, and the dimensions are based off of parallel lines and not sketch points.
Agree with this line of thought on drawings and hand sketches, but no farther. I highly doubt that I could ever draw two lines parallel to with in 0.00025977deg on paper. In CAD sketching nothing should be assumed. The sketch relations, as others have stated, should be turned on to show design intent. I can only imagine the amount of scrapped material cut on the laser from a dxf generated from a model controlled by a sketch that looked correct. In this case, would the part work, probably. Until it’s revised to have 15mm changed to 16mm to improve weld fit up or whatever. The other leg will not move predictably and likely not noticed when a few hundred parts are cut then there’s another revision to lengthen the other leg. It’s just silly. It’s a 3D sketch, not an ANSI drawing.
What kind of hidden constraint can make those lines fully defined but not collinear? I suppose “fixed”?
Let’s ignore the mates then. If the sketch is entirely black and the left line is parralel to the right line, the dimensions between the top line and the middle line indicates parrallelism.
The dimension between the top line and bottom line indicate parrallelism.
The lack of dimension anywhere else indicates that the bottom lines are colinear, since the sketch is black and fully mated.
Yes, it’s multiple choice. Here are the 4 answers:
Construction line connecting the two lines? If this were a SOLIDWORKS drawing, maybe I’d accept this answer. This however is a SOLIDWORKS sketch, as evidenced by the visible Sketch origin. Absent visible sketch relations, you cannot assume anything about the relationship between the three lines.
The “fact” that the two lines are horizontal? How is that a fact when there is nothing (e.g. sketch relations) to indicate it?
Yep. One ‘Fixed’ constraint and chaos ensues:
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To add to what I said, construction lines are often used as a visual aid to point to something. The fact that it was there indicated they were colinear.
Given standard SW colors of black = fully constrained and blue = not fully constrained, I am not seeing how you could get Y not be colinear with X and have Y black, absent a fixed relation. The quiz sketch even shows sketch relations, which I don’t think are needed. I don’t think you even need the construction line. I’ve been trying to get an all black sketch without X and Y in alignment- no luck. Maybe someone can post up how to do it.
As mentioned already, if this were an ASME drawing, the centerline would indicate or imply that they are colinear. But for SolidWorks, you need the relations shown to know.
Not sure which skill they are testing, the ability to interpret a drawing’s intent, or ability to recognize what the SolidWorks sketch solver is doing. I assume the latter since SolidProfessor is a CAD training tool and not a drafting standards training tool. So you’re answer is correct JSculley.
Ok…I “fixed” it. The point being that you need the relations show to truly know in SolidWorks.
We’ve been using Solid Professor for new hires. Based on this I feel like I have to go through them myself, if this is representative of the rest of it I think we’ll be looking elsewhere.
Can you post the file?
Ok…I “fixed” it. The point being that you need the relations show to truly know in SolidWorks.
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OK, I clued in. I did say absent a fixed relation. The quiz question shows the relations, shows X, Y, and the construction line all horizontal, X coincident with the origin. I don’t know how to make X and Y not colinear under those constraints.
There are times to be absolutely precise and times to be pedantic. For purposes of posturing and pedantry, you are correct. For the purposes of a “basic” assessment of SW knowledge and skill, the “construction line” answer is best. Granted, it does assume that the sketch was not made by either an utter incompetent or someone with malicious intent. If I were to open that all-black sketch, I would also assume that the lines are collinear until something broke, then I would berate whoever used a fixed constraint. For all that matter, how do you know that the dimensions are attached to the sketch entities, or that the construction line is actually connected to the others? The lines could all be offset by some infinitesimal amount and fixed.
This is like complaining that a high-school physics f=ma problem is wrong because it is not accounting for relativity.
Not when one of the other offered multiple choice answers is more correct. If I had to choose between the first three, then as I’ve said, the construction line answer is best, but they offered up that fourth choice, which is more correct than the other 3.
This is like complaining that a high-school physics f=ma problem is wrong because it is not accounting for relativity.
Only if the physics problem was multiple choice and included an answer that accounted for relativity that was marked wrong.
