Recent content by vtsteam

LOL!

Gotta be AI.

Hi, thanks, Please read the whole thread carefully.

I'm satisfied with an understanding of the mechanics now, which contributors to this thread helped me to come to. It's a great resource, and I'm glad you all took the time to think about it and explain. As for the actual physical brake. I think it's going to work well for me, as presently...

Hi @erobz, just saw your post after I wrote mine. Thanks for the great diagram and formulas! The scale uses a pressure cell rather than a spring and has a kilogram range, while my actual measurements are in the sub 20 gram range, so deflection is nil. I would say that the only horizontal forces...

A.T. In the case of the drawing, it is ideal perfect construction, and the line representing the beam has no mass, is absolutely rigid, measurements are perfect, etc, etc. It's a an ideal representation which I was using to picture (to myself at least) why the direction of the force on the scale...

Okay in that case I was talking about an Idealized state of equilibrium as a means of visualization for myself. If it's unclear to you or others, I apologize. In the case of the real life brake, I believe that friction could have a small effect because of vibration of the stylus on the scale...

It sounds like you are talking about the real life brake, and not the idealized case drawn above, but maybe I'm wrong about that?

I believe I am not applying torque to the scale surface, assuming everything is square, flat, and level, and the scale uses a solid pressure transducer, not a spring action. I doubt whether greasing the top of the scale or adding a strip of Teflon, would make a measurable difference. But I...

Yes, and I believe in this case theta = 90 degrees. I may be wrong, but this is exactly the crux of why I've gone back and forth on this. And looking at the posts above by others, why they don't all seem to agree. (btw in practical reality I did shorten the length of B as much as I could, and...

Thanks @Baluncore, I agree. Also, re. taring procedure: I lift the arm before running the engine. It is loose with no brake pressure at that point. I turn on the scale and then lower the arm to get the static weight, and record that. Then after running and taking readings, I transfer the...

hi Berkeman, no it was the variable length of the vertical extension B not the lever arm A. I was wondering if varying that made any difference in the scale reading. And so far the conclusion is that it doesn't (in a friction free connection to the scale)

Thanks @A.T. for practical engine measurements purposes it is low enough - a brass rounded stylus on a stainless steel scale surface, and this whole thing is small -- measuring single digit Watts. Thanks @berkeman I'm familiar with only pretty basic graphic vector solutions.... too long since...

Still thinking of how to think! Maybe if I imagine a circle around the pivot with radius A. Then the vertical arm B is tangent to it. No matter how long it is, it's still on the tangent. So any force on B is in line with it. So the scale should read the same no matter how long it is. It's...

I do a lot of hobby mechanical engineering, and occasionally I get stumped with a question about something I'm building which is more of a physics/mechanics question than a specific engineering question. That happened today, so I found this website and asked it. Thanks for being here!