DanG wrote:
Either help the OP or give facts, a diagram, or a formula that
presents your worries and concerns. Continually repeating that
someone is wrong solves nothing, helps nothing, changes nothing.

Perhaps. If you have an engineering background, please review Chris'
12-17-05 12:39 pm post; he says everything is pinned. In that case the
horizontal component of tension is indeed transmitted to the beam via
the pin, and must be included in the diagram and equations, as I
explained early on in this process.

Then go to 12-17-05 2:17 pm and note that he now says the force goes
around the column/beam. The problem with the latter becomes clear when
you look at an FBD of the beam; external moments to do balance. The
horizontal member pushes the beam to the right; per Chris' design, the
only other horizontal force is at the base, and it clearly needs to push
to the left or the whole structure goes flying. Note that the beam is
left wanting to rotate clockwise, which is a contradiction unless there
is some other horizontal force at the top of the beam[*]. We are
looking at two rigid bodies and the pin supporting the load, which gives
seven equilibrium equations. Add that extra support and the system
becomes underdetermined.
[*] the support reactions change, but hopefully you get the idea.

Even if there is a way to build a gizmo that can do all of this and be
statically determinate, it will be far more complex than the pinned
frame, and if built, would be more likely to fail than the frame.


Perhaps you did not notice that OP intends to try his original
concept - win, lose, or draw.

I did notice; that's not the point. What if I were telling people hold
endmills in a tapered chuck and than crank up the feed rate?



He will be watching for empirical
evidence that he is underdesigned.

I'm sure he will.

Bill