Hope to read more about the design of the clamps and mounting system and what makes them stand out over others.
@littlElvis
I still owe you some information about the design of our racquet support, but it was too busy the last couple of weeks.
* But hereby our “racquet support history”:
When we developed our first stringing machine in 1984, all stringing machines on the market had a “2-point support” with “bananas at 6 and 12 o’clock.
* The Ektelon H model was in use “everywhere”.
Stringing tensions were much higher than nowadays and racquets were by far not so strong.
>> Nothing went wrong.
We chose for a 3 point support at the head and a banana at the throat.
* Oversize racquets were invented and Prince came with their 110 sq in aluminum racquet which had to be strung at 72 lbs!
Nothing went wrong on the 2-point supports despite the high tensions!
* But stringers saw much more widening of the racquet head during stringing.
So there was a “smart guy” who invented the “3 – 9 cross bar”, which avoided every widening of the racquet during stringing.
>>>>>>>>> THE RACQUETS BROKE ON THE MACHINE!
So the cross bar disappeared faster than it came, I could not even find a picture on the internet.
The lesson was: If you minimize the deformation of the racquet, the stress in the racquet material will be so high that it cracks.
>>>>> IT IS NOT THE DEFORMATION THAT HARMS THE RACQUET, IT IS THE STRESS IN THE MATERIAL.
In 1992 we developed 2 new machines, the foot-operated MS200 and the electric EM400
Because we wanted a solid basis for the design of the racquet support I asked my colleague on the Dutch Nuclear Research Centre if he could make a computer calculation which showed the stress in the racquet for every type of racquet support.
The calculation was made for the head side of a 110 sq in racquet because the throat side is much stronger.
This graph shows the best position of the supports for 3 options
The conclusions can be:
- A 3-point support with supports on 52 mm from the centre offers the best results.
- A 2-point support (like Ektelon) offers quite good support.
- With outside supports the stress in the racquet depends strongly on the position of the supports. For 110 sqin the best position is at 175, the smaller the racquet head the smaller the distance.
Based on this theory we designed our racquet support “O92” with 3 wide supports at the head side and 2 height-adjustable supports on the throat side.
Apart from the position of the supports it is important that these are very wide so that the pressure between the racquet and the support is low.
The system had a fast clamp system with smooth pins; push down the clamp and rotate the knob 2 revolutions.
In 1998 German string manufacturer Kirschbaum asked us to design a better looking stringing machine than the EM400, the result was the EM500 with an upgrade of our O92 system.
We still use this exact system only with screw hooks instead of the fast clamp system.
For round, tapered or narrow bridges the Babolat retainer is use.