Improving prototype 32.
In stead of a magnet that is fixed to the arm, we use a little rope where the magnet is attached to.
A magnet is only strong when a force is exerted perpendicular to the magnetic surface.
It can not tolerate shear stress.
So when the magnet is attached to a rope, the magnet will move with the collar, when the dog
does not pull too hard.
We also attached a rope to the arm where the dog has to pull to collapse the arm.
On the collar there is a piece of iron.
We kept the old magnet on the arm, if Caroline would want to practice with this one.