# Thread: This problem is just bugging me it seems off.

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IMO, any solution requires assumptions that shouldn't be made.

problem.gif

2. I was prepping a very similar animation. As stated, assumptions are required (I've made similar comments about ambiguous drawing assignments in previous posts), but lets roll with it. A .31 thickness at a vertical angle, though, should be scaled to 0.31/Cos(30 degrees).

3. To complete this part - 3 assumptions must be made (but logic can be used).

Assumption 1 - that this line is horizontal. (Logic - I also tried with assumption that 1 and 3 symmetrical angles about a horizontal line, but that is a "bigger" assumption and the result isometric did not match given image.)

Assumptions.jpg

Assumption 2 - the thickness of the inclined feature is .31 same as base feature (logic - duplicate dimension not given). (Hint: the red line is not the same as the thickness of that inclined feature.)

Assumption 3 - the 1.5 is to the tangent of the arc. (Logic - changing any of the (reference) dimensions to 1.5 varied too much from the given isometric figure.)

I'm going to lunch now. I'll be back in a while to show how to get the length of the red line.

4. So I think I am on the correct track now thanks for the hints.
I did it in Solidworks also to help visualize.

P09 - 33.jpgp09-33.jpg

5. Looks like you got it.

The key is to do an auxiliary view of the side of the inclined feature to get TSS.

Auxiliary Solution.jpg

Here I have done from 3D model, but easy enough to do in 2D. The location and orientation doesn't really matter as it is all (green/red boundary) is all from known information (if we assume base and inclined feature same thickness.

6. Using Parametric dimension and geometry constraints - now have enough information to fully define the base shape.
Geometric Solution.PNG

Before you turn in this assignment - you made a typical beginner mistake on the hidden lines from your Counterbored Holes (check the SolidWorks drawing solution).
Hidden Lines.PNG
In fact, there is actually an object line across most of that in the same location. Object lines take precedence over hidden lines.

7. I told you the OP only needed a hint. I've been out all day. ReMark I drew the plan using the method Nestly showed except I used .358 as the plan thickness of the slope. In this case I would say that the term educated guess is more applicable than assumption, in a lot of cases geometry is so obvious to the person drawing it that they neglect to add dims or angles (I do it a lot) an assumption would be when that top angle needs to be 95° and is the only way to draw the part, but that is just semantics.
PS here was my drawing

8. Originally Posted by JD Mather
Using Parametric dimension and geometry constraints - now have enough information to fully define the base shape.
Attachment 44964

Before you turn in this assignment - you made a typical beginner mistake on the hidden lines from your Counterbored Holes (check the SolidWorks drawing solution).
Attachment 44965
In fact, there is actually an object line across most of that in the same location. Object lines take precedence over hidden lines.
Yeah I got the object line. Was still working through the drawing .

9. Assumption or guess, there's no way I'd put my name on drawing reproduced from the information provided. As JD pointed out, it is assumed the that 1.5 dimension is supposed to be from the tangent to the corner, even though that's not how it's dimensioned. Is it dimensioned wrong, or did we all make the wrong assumption? To answer that question, yet another guess has to be made.

problem1.jpg

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Point taken, and I hadn't picked up on that, but I would now say that I drew it wrong the first time round, and would redraw it, using the quadrant of the circle as the rotation point. I would enter a plea of carelessness for missing the dimension clearly coming from the quadrant and assuming it was from the tangent, whilst trying to draw attention to the thickness of the sloping face. The main problem in cases like this is the Authors remain silent and the true answer unsolved. Though I would be fairly happy to initial my drawing now (in small letters on the back).

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