The ball itself is abut the same size and weight of the ball found in the Traxsys Joystick only it is perhaps fractionally heavier to move, especially when using fingertips.
Like the Traxsys range the buttons are mounted 'sub-flush'. This means that accidental pressing is far less likely as they are protected by the shell of the unit that acts as a sort of keyguard for the rollerball. The buttons are colour-coded with the left being RED and the right being YELLOW.
Accurate double-clicking requires an certain amount of fine motor control and can be very difficult for some to accomplish. The n-Abler has a built-in double-click button that performs this function accompanied by a double-beeping noise (this can be disabled, see below). For any pointer control device it is possible to use Windows mouse accessibility options to change the behaviour of double-clicking.
Holding down the mouse button whilst moving the rollerball, "Click & Drag", is another extremely difficult task to accomplish for people with physical difficulties. The n-Abler has a dedicated button that holds the left mouse button down until another button is pressed, allowing a user to drag items around with the rollerball.
The n-Abler has an X/Y Axis button that restricts movement to one axis at a time - horizontal then vertical - to allow a user to move to their target even with the most uncontrollable movement. I like this feature, which is also found on the Traxsys Penny & Giles Plus, but I would like to see on-screen guide lines that would support it and allow a user to pinpoint their X and Y axis. The Single Axis Button also acts as a scroll wheel (on the third press) and can be used to scroll up and down windows. I think that this additional feature, while useful for some, would only confuse many users with cognitive difficulties.
The unit has four built-in speed settings. Although mouse (and therefore rollerball) speed can be adjusted in Windows accessibility options, having a function on the rollerball makes the process quicker and is essential for those many networks that still refuse to allow access to the Windows accessibility options. A small button on the rear of the unit cycles through the speed settings.
The rollerball has two standard switch inputs on the rear of the unit. This is for supplementary access switching and cannot be used for switch scanning. Find out more about types of switch access.
This is a very useful feature that is not found on any other rollerball that I am aware of. Sometimes it is not appropriate to position or mount a rollerball in its intended portrait position and many users could benefit from positioning it landscape-style or at another jaunty angle. The rollerball can be easily told that its direction has changed simply by putting it into 'learn mode' and pushing the new 'up' direction.
The only other way I have seen that this can be accomplished is by using Microsoft's IntelliMouse software.
The n-Abler rollerball makes various useful beeping tones to indicate what it is doing. For example the double-click buttons emits a quick 'beep-beep' and the drag lock button produces a two-tone sound when it is active and when it turns itself off.
It is easy to disable all the audible feedback of this rollerball.
The n-Abler rollerball has three screw holes on the base of the unit that allow it to be attached to a mounting plate for use on a wheelchair or other permanent fixing.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 2.5 License.