Recent content by EcoMan

Thanks, CheckerHater. My shorter leg is on a datum, so I'll base the tolerance on my longer leg.

Hello, Why does ISO 13920 say that the length of the shorter leg determines the applicable tolerance for the angular dimension of a weldment? Wouldn't the deviation be dependent on the longer leg?

Can't a dimension be critical but, for example, the tool to machine its feature not be subject to excessive wear, thus requiring FI but not IPI?

Hello, I am an engineer but not in Manufacturing or Quality. The company that I'm working for does first article inspection (FAI), in-process inspection (IPI), and final inspection (FI) on any part manufactured in house. My understanding is that the company's FAI looks at all dimensions on...

Just to clarify, I'm interested in whether the parts are affected by which cavity that they come from. Assume balanced mold filling.

Hello, I would like to test for a difference between a single lot of injection molded parts from each cavity of a symmetric two-cavity mold. I'm not sure whether to use a two-sample t-test or a paired t-test. Which test is appropriate for this case? I assume that the answer doesn't change if...

Hello, Left and right lungs are pneumatically in parallel. The compliances of springs in parallel add as reciprocals, so why do lung compliances add directly?

Thanks, MintJulep, for your reasoning! That is a convincing argument for A being the only correct option. I see an Engineering Language/Grammar Skills forum where I suppose that I should've posted my original question.

Not to get too philosophical, powerhound, but something can be clear yet incorrect. For example, Clear and correct: (2 / 1) + 1 = 3 Clear and incorrect: (2 / 1) + 1 = 1 Unclear and correct: 2 / 1 + 1 = 3 Unclear and incorrect: 2 / 1 + 1 = 1 Everyone, let's forget about drawings and pretend...

Thanks all for the feedback so far. My question is general, not just for drawings. Goober Dave, I don't see anything in the IEEE Editorial Style Manual (www.ieee.org/documents/stylemanual.pdf) that addresses this. Besides which option is clear, I'm wondering which is correct. I don't think B...

This seems like the most logical forum to post this question. For a cube that measures 2 inches on each side, which one of the following is what you would write, assuming 8 in^3 isn't an option? A. 2 in x 2 in x 2 in B. 2 x 2 x 2 in C. 2 x 2 x 2 in^3 D. (2 x 2 x 2) in^3

You're right. I shouldn't have used the same variable (K) to denote both the polar moment of inertia and the torsional constant unless the cross section is circular. They are different for, as an example, an elliptical cross section. Consequently, twist of noncircular sections is not related...

I'm sure. Roark (1954) says the same thing.

Hello, The chapter on torsion in my Advanced Mechanics of Materials textbook from university says that, for a solid section with a given cross-sectional area A, stiffness is greatest when the centroidal polar moment of inertia K is least. What confuses me is that twist (= TL / GK) is inversely...

Thank you all. The book doesn't talk about coherence, frequency, or phase--just identical machines in a theoretically free field. hydtools, that's a good link. It shows that SPLs, not ony PWLs, can be combined and gives the formula (but not one for adding unequal SPLs).