Daystate MVT Technology revealed
In response to many queries triggered by an earlier security leak, I now think it is just as well I reveal more about our new technology developed by Harper Classic guns for Daystate, rather than individuals “second guessing” and causing confusion.
MVT is short for “Mapped Velocity feed-forward Technology. This consists of two distinct technologies:
Power Mapping:
Where the gun is “mapped” (analogous to automotive electronic advance and retard mapping) to produce a constant power output, this is done by varying the knock-open valve hammer effort according to pressure. When the pressure is high, the valve is hit harder by the hammer to overcome pressure induced valve resistance. When the pressure drops the valve is not hit so hard to compensate, giving a flat power characteristic.
To do this an accurate built-in pressure sensor is used to digitally control the hammer effort to open the valve using a mathematical algorithm and a predetermined map of the gun’s performance characteristic. This technique produces impressive results with a flat power plateau over a very wide range of reservoir pressures. It has the advantage of accurately compensating power levels, even when the reservoir pressure changes abruptly (such as part filling, “topping up” the gun).
Velocity Feed Forward:
The velocity is measured for every shot, and the hammer effort is adjusted to give a constant velocity output (something like pre-detonation detection used in engine management systems). A built-in sensor light gate is built into the barrel shroud and the velocity is measured against a preset value and a simple mathematical algorithm is used to vary the hammer effort. This too produces impressive results; however it does have the disadvantage of having to “learn” the set velocity. This is when the hammer effort has to be changed by “trial and error” to attain the desired velocity and then maintain it.
When these two techniques are employed then the best of two worlds are realised. Constant velocity/power is maintained over changing temperatures and when re-filling the gun without “re-learning” the velocity, constant velocity is maintained with different ammunition and it is possible to fine tune velocity to suit individual pellets. It also allows control of the muzzle energy, preventing energies over 12FPE by using different weight pellets or changing the fill pressure of the gun. Velocity feedback alone can be compromised in this way.
Combining these two technologies also allows the accurate setting of lower energy levels. Current pr-production guns can be altered from their factory set maximum energy to velocities as low a 400FPS. Lower velocities have to be “learnt-in” and 785FPS to 400FPS change can be learnt in about 5 shots. Most velocities are learnt-in with 10 shots. Please note that the learning-in process is not needed when operating at the factory set energy level.
To give an idea of the performance of this new technology, a modified Mk3 Sport will produce about 240 shots at +/- 7FPS with un-weighed, us-sorted pellets in 177 calibre.
Gun Display:
The gun has a back-lit 16X2 LCD display. In normal operation it shows:
Reservoir pressure in BAR
Velocity setting on switch on and velocity of last shot in FPS
Shot count
Battery on-load voltage
Magazine shots left
The gun also has a full programming menu including velocity setting where the velocity can be set from 400FPS to the factory limit (for sub-12FPE guns) or higher for FAC guns. The display also shows charging progress when recharging the battery.
The gun will be officially launched at the Tackle and Gun show at Stoneleigh later this month, and there will be opportunity to shoot it at Rivington, also later this month.
What next, on board mp3 player?
) you'd better be qualified in IT.
