Nice work Peter, thanks.
Cheers, Don
Would you purchase one of these Don Paul, if the price was right? Unfortunately I don't know what that would be, but let us say it was under a grand for a longer model gun, say a 130 cm.
P.S. I tried to pm you just now, but the system said that you already have too many conversations going at the moment!!!
Although the 10 atm gauge pressure is not high, the interior volume of the "Dreamair" gun is. It would be handy to use an adapter so that an automobile 12 Volt DC portable compressor could be used to pressurize the "Dreamair". I made an adapter for my pneumatic guns that can use a 250 psi portable compressor to rapidly push the gun up to 200 psi, then I do the rest of the pressurizing with the supplied hand pump. I attach a "diagram" of what I think this adapter would look like.
How the "Dreamair" gearing or "CVT" action works.
Very nice work Peter. Thanks. I'll clean out more PMs this week.
Cheers, Don
I was recently thinking about how the "Dreamair" speargun will be marketed and came up with the following rationale of why anyone would purchase one of these very different spearguns.
DREAMAIR SPEARGUN
Marketing
One of the first questions posed before a marketing campaign starts is “what is the offer”.
The answer to this question sets the theme for the campaign.
The offer is:-
A highly versatile gun with respect to its infinitely variable power output that reduces the decision of which gun to take on a trip to a single one, namely the length of the gun required. Everything else is adjustable in the “Dreamair” speargun and thus it requires only the transport of a single weapon, unless the spearfisherman wants a longer or shorter weapon to accompany his main speargun.
Now what do you think?
Any feedback? The project needs input and a range of potential users to comment on what they would be looking for in a gun which is basically a crossover design in that it is an arbalete with a closed, non-consumptive (of gas), pneumatic energy accumulator.
It seems a complicated speargun to me. Not sure what the advantages are if any, and if they justify the price and unknown durability/maintenance factors.
Some people speculate that a complicated gun will require more maintenance, but I think there will be very little with the “Dreamair”. Except for post-dive rinsing of the gun in freshwater and checking the outer cables for wear there is nothing more to do. Maybe check the air pressure level in the gun. Water never gets inside the gun as it is a closed system, the only place where a pressure boundary is crossed is at the winding drum axle (or axles) where seals act on a rotating shaft.
I'm waiting to see it clearly in a video.
I'm waiting to see it clearly in a video.
Well there is the shooting video, but I agree that more of the gun needs to be seen as it has undergone some changes since that video was made. I have already told the inventor that I wish to order a gun, so I am prepared to buy one based on what I have seen to date and which I have posted both here and elsewhere.
So much has been said about it. I'm looking forward to your video review Pete. I'm sure it will be comprehensive.
So much has been said about it. I'm looking forward to your video review Pete. I'm sure it will be comprehensive.
No stone will be left unturned!
I wonder if the winding drum covers will be fitted for weedy and rocky areas in order to protect the winding drum tracks. The track grooves need to be maintained in good order so that the cables wrap in exactly the same way each time the "Dreamair" gun is fired.
That was actually my main doubt. I can't see that happening consistently even under normal conditions.
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.
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.
First "Dreamair" spearguns released will be 100 cm models. The wishbone draw on the top deck is equivalent to the spiral track groove length on the winding drums.
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.
"Dreamair" underwater rifle using CVT action cable drive system powered by energy stored in non-consumptive pneumatic accumulator will soon be released to the spearfishing market.
In anticipation I asked whether a "Dreamair" speargun will fit inside a neoprene "gundom" and the answer is that it does, provided that you remove the reel from the gun. A "gundom" is a zippered speargun cover made from “camo” neoprene wetsuit material and will protect the “Dreamair” gun’s outer winding drums from handling impacts. I use these soft covers as you can roll them up when not in use unlike a hard shell gun case.
Now we just have to wait, but as I mentioned a long time ago the signal that things are moving is that the http://www.infinitengines.com web-site will come back to life. Very early on it showed the astronaut floating around with a white "Dreamair" in a CGI rendition and a few other dramatic and eye-catching poster style presentations, but then it all stopped working and the link was broken. So just click on it every now and then to see if anything is happening as Andreas thinks the next posts here and elsewhere should be when the "Dreamair" gun is officially launched. Hopefully that will not be too far away as I have been “stoking the fire” so to speak in order to maintain interest and build momentum.
On the Greek spearfishing web-site where the project was first announced I found these interesting views of inside the barrel of a multi-axle gun as can be seen by the two sets of sub-pulleys being used. This would be a four axle gun as there are four cable strands running towards the muzzle, one cable per inner winding drum on each axle. You will need to click on the second image to see all of it as it extends for the full width of the screen.
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