structural:reformatting, stylistic:tone
Elastic 3D mice

At DLR an elastic 6DoF sensor was developed that was used in Logitech's SpaceMouse and in the products of 3DConnexion. SpaceBall 4000 FLX has a maximum deflection of approximately 3 mm (0.12 in) at a maximum force of approximately 10N, that is, a stiffness of approximately 33 N/cm (19 lb /in). SpaceMouse has a maximum deflection of 1.5 mm (0.059 in) at a maximum force of 4.4 N (0.99 lb), that is, a stiffness of approximately 30 N/cm (17 lb /in). Taking this development further, the softly elastic Sundinlabs SpaceCat was developed. SpaceCat has a maximum translational deflection of approximately 15 mm (0.59 in) and maximum rotational deflection of approximately 30° at a maximum force less than 2N, that is, a stiffness of approximately 1.3 N/cm (0.74 lb /in). With SpaceCat Sundin and Fjeld reviewed five comparative experiments performed with different device stiffness and transfer functions and performed a further study comparing 6DoF softly elastic position control with 6DoF stiffly elastic velocity control in a positioning task. They concluded that for positioning tasks position control is to be preferred over velocity control. They could further conjecture the following two types of preferred 3D mouse usage:

3DConnexion 's 3D mice have been commercially successful over decades. They are used in combination with the conventional mouse for CAD. The Space Mouse is used to orient the target object or change the viewpoint with the non-dominant hand, whereas the dominant hand operates the computer mouse for conventional CAD GUI operation. This is a kind of space-multiplexed input where the 6 DoF input device acts as a graspable user interface that is always connected to the view port.