Friday, September 21, 2018
  • Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:

    • Join over 40,000+ fellow diving enthusiasts from around the world on this forum
    • Participate in and browse from over 496,000+ posts.
    • Communicate privately with other divers from around the world.
    • Post your own photos or view from 7,300+ user submitted images.
    • All this and much more...

    You can gain access to all this absolutely free when you register for an account, so sign up today!

Infinitengines "Dreamair" pneumatic speargun

OP
OP
popgun pete

popgun pete

Well-Known Member
Jul 30, 2008
2,109
318
123
Australia
I was just thinking that high speed spinning items can function like a gyroscope which would tend to stabilize the "Dreamair" gun during the shot as the winding drums and axle certainly spin rapidly. Another consideration is that having been spun up to a certain velocity how is their rotational inertia handled in order to bring the spinning assembly to a halt. There does not appear to be a wishbone catcher as such, so that task must fall to the inner cable anchor point which would receive quite a jerk when it pulled up the winding drums and axle assembly to stop them spinning after the shot.
Andreas Zournatzis himself supplied the answer to this query. What happens is at the end of the shot the piston has reached its most rearwards travel in the gun (remember the piston moves forwards when the "Dreamair" gun is being cocked) with the axle and winding drums assembly still spinning. As they continue to rotate they will start to wrap the inner cable in the opposite direction to which it is usually wound on the inner drum, in which case the piston is dragged forwards again against the air pressure in the gun. This serves to brake the spinning assembly as its rotational inertia cannot do much work against the gun's start pressure, hence a form of "pneumatic braking" takes place on the spinning axle and winding drums assembly.
 
OP
OP
popgun pete

popgun pete

Well-Known Member
Jul 30, 2008
2,109
318
123
Australia
The "Dreamair" speargun is a high speed winching device using a closed cycle pneumatic energy storage accumulator to catapult spears at high velocity via a CVT action cable drive system. As such it constitutes a complete revolution in the field of underwater arms for spearfishermen seeking a versatile weapon of wide ranging shooting powers and high levels of accuracy.
 
Likes: Kodama