Featured Product from Daco Hand Controllers
"Displacement" joysticks are by far the most common type and are what most people envisage when they consider joysticks. Force applied to the handle causes it to move over many degrees (usually between 20 and 30). This movement is detected and converted to an electrical signal by a potentiometer or a non-contacting technology device if a proportional output is required. If not, a simple switch arrangement is used. "Force sensitive" or "stiff stick" joysticks use strain gauges, attached to a fixed metal post, to convert applied force into a proportional electrical output. Typically a movement of less than 1mm is needed to achieve full scale output. The MP1 Displacement joystick range has been developed for military or demanding commercial applications that require robustness and high reliability combined with optimum accuracy and 'feel'.
The use of potentiometers to sense displacement, in preference to non-contacting sensors, ensures a low component count and consequently higher MTBF figures. Potentiometers also have lower electrical emissions and are less susceptible to interference from external sources. For ultimate reliability the particular potentiometers used by Daco are IP65 sealed, conductive plastic devices that have none of the problems sometimes encountered with open track and wire-wound potentiometers. The outputs are referenced to centre taps to remove any offsets and give stability ensuring that, at zero deflection, the outputs are not affected by supply voltage. Direct coupling of the potentiometers to the gimbal mechanism totally eliminates backlash.
While most of Daco's joysticks in the past have used potentiometers to sense displacement for the reasons outlined above, Hall effect sensors are also now used where the application so permits and / or where you so prefer
The gimbal mechanism itself is, to the best of our knowledge, the strongest commercially available. Its components are machined from steel or aluminium and are supported by sealed stainless steel ball races mounted in a formed frame. This, in turn, is welded to a panel-mounting flange that is machined from aluminium. The use of stainless steel and anodised aluminium also provides excellent corrosion resistance.
Rising from the gimbal mechanism is a hollow stainless steel central shaft that is used to mount a grip. The bore of the shaft can accommodate up to 24 wires for attachment to switches, triggers or miniature force joysticks. This facility allows a choice of many different handgrip configurations based either on Daco's MG1 modular grip or on a fully customised pattern.
The hollow shaft passes through a sprung plate that acts as a return-to-centre mechanism. The design of the plate is such that the force required to operate the joystick is the same regardless of the direction of movement.
For some applications it may be better to have some "bias" in the individual axes so, on custom-built hand controllers, Daco can fit a profiled plate. Similarly, if a lower return-to-centre force is required, "lighter" springs can be factory fitted.
Full-scale output on standard modular joysticks is provided from the X and Y axes simultaneously by using a square 'gate'. The third, Z-axis, is operated by rotation of the grip. All axes can be operated together and all provide ±20° of movement with a return-to-centre action.
When the MP1 is mounted into a panel a gaiter, manufactured from EPDM rubber, gives sealing to IP66 whilst remaining flexible over a wide temperature range.
As the base for a custom built hand controller the MP1 modular joystick can be modified to have any one, or any combination, of the three axes activated. Other special variants have included put-and-stay; high and low force; detent and position sensing switch mechanisms. Smaller size displacement joysticks are also available and a miniature displacement joystick is currently under development.
As with all Daco products, MP1 series joysticks are covered by a two-year warranty and are manufactured under a BS EN ISO 9001 approved quality system.
To learn more about the Daco joystick that will suit your needs use the "See Product Details" weblink on the right for options and characteristics