@villis
...But stringing badminton racquets is a completely different matter with 25 to 30 lbs tension.’
I do not understand why would you want to string badminton racquet on machine that is not suitable? My cheap machine has two positions and two shapes for side supports, one for badminton other for tennis racquet; what is exactly the issue and how is it related to external/internal support?
@villis
Furthermore I am a mechanical engineer and when all my information is seen as sales promotion because it is on the Stringway website this makes my information useless.
You do realize that there might be other engineers here, therefore information better be somewhat substantiated in the way it can be independently checked. Otherwise it resembles a promotional material no matter where and by whom it is posted. In a scientific community they learn to challenge claims made by even Nobel prize winners, and for a good reason so.
@villis
The graph that you doubt about is a computer calculation of the stress in the racquet. We made this when we designed our support.
At that time you designed your support, even modeling a simple bending rod was a significant challenge (and to some degree it is even today, depending on one's abilities and access to resources). So yes, it has to be doubted, especially if one does not even disclose the model assumptions.
It may very well be correct, or depend too much on racquet shape, or model could be too simplified to apply to modern racquets.
@villis
With this statement I mean that outside supports create zero deformation but high stress. So zero deformation does not mean zero stress.
Sorry, but there is no stress without deformation. You should not post such absurd claims.
I can understand that you may be implying specifically "no bending deformation", but that ONLY means that racquet shape has worked as intended and resolved applied forces into compressive stress as per design. This is why they use carbon fiber. Compressive stress is still causing deformation which is small, harmless and you do not see it with naked eye. One should use strain gauges to detect such deformations.
@villis
Just have a look at this “beam in the wall theory” .
The question is: What support is best for the beam?
I understand that you will doubt this explanation also.
AGAIN, what a straight beam has to do with tennis racquet. We have discussed it before, but you keep coming back with this questionable analogy.
You may know that in order to avoid the need for support of straight beams, people have invented Arches as early as 2nd millennium BC, if we can trust Wikipedia. Now have a look at tennis racquet and see that it somehow more resembles arch rather than a straight beam. But you choose to discuss straight beam, apparently because arch would not support your claims, as easily.