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All About Guns What's your weapon of choice, and why? Discuss the beloved speargun here! |
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11-09-2018, 02:44 AM | #106 |
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Re: The Infinite Engines Dreamair moves from dream to reality
I would be interested but only after initial use in the field and some positive reports of users.
Not willing to invest in a prototype or beta version. Unless it’s going to be a game changer in power and accuracy I am afraid that I may remain a niche product. On the other side I hope that it performs exceptionally well and sets a new standard for innovation. |
11-09-2018, 02:56 AM | #107 |
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Re: The Infinite Engines Dreamair moves from dream to reality
Well the power aspect all depends on the CVT action of the winding drums. They provide varying leverage or gearing as you pull the wishbone back, so besides the efficiency gains from using a near frictionless pneumatic "spring" inside the gun the ability to cock a gun which would normally be too hard to load is where the power advantage will be, the question is how much of an advantage does it confer on your ability to load the gun? Until we get a feel for the loading effort we will be none the wiser and for that we need a gun to try out.
Judging by the sizes of the drums it looks like a 4:1 leverage at the end of cocking with a 1:1 leverage or direct pull at the start. Maybe not quite 1:1 at the start as it is hard to judge the diameters exactly and could be 1.1:1 as outer drum start diameter is slightly larger than inner drum start diameter, but you can judge for yourself using the drum and axle assembly photo. The inner cable which is fully protected from the elements inside the completely sealed inner chamber of the gun is thicker than the outer cables and their respective drum spiral groove widths are sized accordingly. Last edited by popgun pete; 11-09-2018 at 04:47 PM. Reason: more info |
09-09-2019, 04:12 PM | #108 |
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Re: The Infinite Engines Dreamair moves from dream to reality
Here it is, the Carbon Dreamair!
https://youtu.be/pZnqMrFt7ys Last edited by popgun pete; 09-09-2019 at 06:10 PM. |
09-09-2019, 04:41 PM | #109 |
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Re: The Infinite Engines Dreamair moves from dream to reality
Looks to be a stable gun platform and consistent shooter even when pumped up to 24 bar. Note that the piston inside the Carbon gun is smaller and is not oval as in the alloy gun and from memory is about half the cross-sectional area. The two loaders, the simple version and the block and tackle pulleys in the hooks version, both work OK as can be seen in the video. If you look at the graphs for each shot then you can see the gun power going up and up as the pressure in the gun is increased. Not very noisy, just the usual pneumatic click.
Last edited by popgun pete; 09-09-2019 at 06:23 PM. |
09-11-2019, 07:22 PM | #110 |
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Re: The Infinite Engines Dreamair moves from dream to reality
This diagram shows the outer cable/wishbone track in plan view as the gun shoots. Cocking the gun the process is reversed.
Last edited by popgun pete; 09-12-2019 at 09:43 PM. Reason: new diagram |
09-11-2019, 10:30 PM | #111 |
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Re: The Infinite Engines Dreamair moves from dream to reality
And how the system winds off and winds on the cables inside the gun's pressure chamber while doing the exact opposite with the long external cables that are effectively long wishbones.
Last edited by popgun pete; 09-11-2019 at 10:48 PM. Reason: adjusted the diagram |
09-14-2019, 05:03 AM | #112 |
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Re: The Infinite Engines Dreamair moves from dream to reality
A long time back on the Greek spearfishing website I found some tables which were all in Greek. I put one of them in the auto-translator after converting the image to text and this is how it came out after some manipulating. This table will be for the 1000 mm^2 piston equipped gun.
Just to give you some sense of proportion what Joules mean take a look at the table for the Aquatech "Black Sea" hydropneumatic hydropump gun. The Joules here are what came out as I think that they were calculated using the velocity and mass of the spear. Energy is measured in Joules and for a flying spear is calculated by the formula E = 1/2 x spear mass x velocity squared. Cocking the gun took energy and this is measured by the work done in pulling a wishbone back for a distance on the gun, the force goes up as you draw the band back and this can be represented by a triangular graph where the energy is proportional to the area under the graph. Unfortunately you never get out all the energy that you expended in loading, but most guns can put enough into the spear to drive holes in the fish and hopefully fatally damage it. |
09-22-2019, 07:06 PM | #113 |
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Re: The Infinite Engines Dreamair moves from dream to reality
Here is a diagram estimating a gun of 110 cm wishbone draw with a piston travel about 34.375 cm based on a multiple of 3.2 with respect to the relation between piston travel and wishbone travel. Start pressure is 23 atm gauge or 24 atm absolute.
Note that the wishbone energy graph will not necessarily be this shape due to the gearing changes as the wishbone moves along the gun. Pulling the piston forwards in a "Dreamair" as you load the gun the pressure increases in the pneumatic chamber, hence force on the inner cable goes up, but counteracting that the gearing provided by the ratio of drum diameters at any given instant increases due to the outer drum getting bigger as the cable moves inwards on the drum (towards the barrel) while the inner drum is getting smaller as it winds cord on towards its narrow end. |
10-18-2019, 10:44 PM | #114 |
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Re: The Infinite Engines Dreamair moves from dream to reality
It occurs to me that the “Dreamair” gun’s spinning axle and drums may act to stabilize the gun during the shot, rather like a gyro-stabilizer.
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10-19-2019, 01:56 AM | #115 | |
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Re: The Infinite Engines Dreamair moves from dream to reality
Quote:
Do you think that gyro stabilizing effect is intentional and if it would be possible to perceive it ? It seems to me that it is just a by product of the system used. |
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10-19-2019, 01:59 AM | #116 |
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Re: The Infinite Engines Dreamair moves from dream to reality
I’m also wondering how much it can be felt given that the drums are probably quite light and pretty small in diameter.
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10-19-2019, 02:10 AM | #117 |
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Re: The Infinite Engines Dreamair moves from dream to reality
I am sure it is not intentional, it will just be a by-product, but the drums are larger than simple rollers, the spiral tracks on them are the length of the wishbone draw, plus inside there is the inner drum as well. They all spin with the axle in the ball bearing mounts inside the gun's pressure chamber.
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01-12-2020, 04:34 PM | #118 |
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Re: The Infinite Engines Dreamair moves from dream to reality
A new photo of the "Dreamair Unreal" has just been added to the site. It appears to not have the outer drums fitted as you can see the ends of the axle.
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01-19-2020, 01:09 PM | #119 |
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The Infinite Engines Dreamair moves from dream to reality
Receiving a patent was probably another mandatory step before bringing the Dreamair to the market. With that out of the way let’s hope it will become available soon. |
01-19-2020, 02:19 PM | #120 |
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Re: The Infinite Engines Dreamair moves from dream to reality
The international patent has been around for some time, the actual US patent has been a long time coming. The priority date is the key.
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