New oleopneumatic invention traction roller Dyneema

  • You can see the target in the distance being hit and moving with the shaft impacts, judging by the changes in reflection from the target's white surface. The shaft flies very quickly and there seems to be little recoil as the "Dreamair" gun shoots. I think that the multitude of shots shown indicates that the gun works reliably and consistently which is what you want in a speargun. Considering the technical challenges that had to be overcome, and I had my doubts earlier due to the attention to detail required to make everything work, I think the gun is a great achievement.

  • Here is the version of the loading device with a pulley built into the hooks; the metal ring attaches to the shaft as a fixed anchor point that you can then pull against as you haul the wishbone(s) back. Doubling the line at the hook pulleys halves the pull effort, but you have to pull twice as far which is what you expect to do with a "block and tackle" device. A very ingenious design!


    The loading device is apparently the "Dreamloader", so the photo has been updated accordingly.

  • Four cross-sectioned views of the "Dreamair" show its internal layout and the compact arrangement of the winding drums, axle, bearings and seals.


    Note that these views are looking at the gun with it turned upside down as the inlet valve opening is underneath the muzzle. The shaft guide track is facing downwards and thus out of sight.

  • Here you can see the spiral cable tracks on the winding drums, the housings for the spinning axle roller bearings and seals are screwed into the gun body, hence the screw threads on their surfaces. The "window" in the inner drum is the inner cable attachment point. The varying leverage or CVT aspect is obtained from the ratio of the drum diameters at the various points on their surfaces where the cables are simultaneously pulling or being pulled.

  • True gun porn that part. It's funny to look at that finely machined complex part ,then think about my Tahitian friends carving guns from Hibiscus wood...than wonder which gun will harvest more fish?


    Cheers, Don

    "Great mother ocean brought forth all life, it is my eternal home'' Don Berry from Blue Water Hunters.


    Spearfishing Store the freediving and spearfishing equipment specialists.

  • More likely the hunter behind the gun is the key determinant, the gun being just a tool. And the opportunities for prey in the area, some places I have speared it took hours to capture a quantity of meat that in another location and time of day took a fraction of the time.

  • Just to clarify how the cables travel on the drums during the shot, black marks the start positions. During loading the cables reverse this movement, thus as one set of drums wind on the other winds off or vice versa. The "Dreamair" speargun is essentially a pneumatically powered high speed winch for launching the spear with the operator re-compressing the air storage system for the next shot via their manual loading effort.


    Compressed air energy storage is much more efficient than using stretched rubber bands which suffer loss during "band soak" in their loaded up state.

  • I have been out of action for many months, but thought that I would check on progress with the inventor, so I have just sent him a message. These guns were never going to be easy to produce with their spiral track winding drums, located both inside and outside the gun body, but that would very much depend on how those parts were eventually going to be manufactured for mass production versions. Particularly with regard to the implications for the eventual selling price. Prototype guns were made in a number of construction materials, but as far as I know the drums were always machined from metal stock on a multi-axis milling machine. That made for expensive parts! Molded drums would need to have the necessary anchor strength and track durability as the cable drive places a lot of load on them, particularly on the groove flanges, however molded parts can be churned out once the dies are made.

  • I was just thinking of you last week Pete, Hope all is well. I hope some day to get my hands on one of these advanced guns.


    Cheers, Don

    "Great mother ocean brought forth all life, it is my eternal home'' Don Berry from Blue Water Hunters.


    Spearfishing Store the freediving and spearfishing equipment specialists.

  • There is a new version of the gun now being prepared. I would like to lay my hands on one, even if it was a first generation alloy gun, just to get a feel of the loading effort as the gearing changed with the varying radius that cables pull from on the inner and outer winding drums. You start off at a small radius on the outer drums (near their outer ends) while the inner drum is wrapping onto a large radius and at the end of the wishbone draw you are pulling on a large radius (inner ends at the maximum radius of the outer drums) with the cable fully unwound while the inner cable is completing wrapping of the inner drum at a much smaller radius. Thus leverage works against you at the start of the draw, but works for you at the end when pressure in the gun has reached its maximum due to compression.


  • After looking at the video a number of times I now understand how the simple version of the loader works. The blue cord passes through a hole in each loading handle which is superimposed on a narrow slot as seen in the magnified view of that area of the loading handle. The loading handle is twisted so that the knot in each cord, which easily passes through the hole, will catch in the side slot and that allows the cord to be dragged back.


    The simple wire hooks are first attached to the actual wishbone and the loading handle on each side is then pulled back to drop the rear loop of the blue cord into the shaft notch or onto a shaft tab. Then the loading handles are slid forwards on the blue cords, which are now under some tension, to engage the second set of knots located immediately behind the hooks by twisting the loading handles in order to catch onto them. Then you can drag the actual wishbone back to the shaft notch or tab. This creates slack in the rear section of loader cord so that the actual wishbone can replace the cord loop which will now disengage from the shaft notch or tab.

    Attached Thumbnails

    Edited 4 times, last by popgun pete: I decided to separate the loaders, "Dreamloader" will follow as combing the two in one post was confusing ().

  • The “Dreamloader” works in a similar fashion to the simple loader except that instead of pulling the wishbone back directly this loader uses a pulley system that is incorporated in the hooks. This anchors one end of the cord on the shaft using a metal anchor loop so that half the load at any draw position of the cable wishbone is taken up by the shaft itself and the other half is taken up by the loading handles. That means for the same rearward displacement of the wishbone the cord has to be pulled twice the distance it was moved previously with the simple version. A schematic diagram shows how this “block and tackle” arrangement works in the accompanying attachment. This device is intended to make loading easier at higher loads.


  • I have been told that the manufacturing processes will be completed by September for an all new construction "Dreamair" using advanced materials. So the alloy bodied "Dreamair" guns that we have seen so far are prototypes and not necessarily what will be offered for sale. Parts manufacture will probably be sub-contracted out to various companies who specialize in different areas. I have no other details, however you can probably guess what may be coming if you think about how spearguns have evolved in the last decade or so, including a few pneumatic spearguns. There will be different versions, including a premium model and a more basic model, but all will use the same operating system, only they will be manufactured from different materials.

  • The new model "Dreamair" is based on carbon fibre (or fiber) for the body. A few companies such as Salvimar have a carbon fibre tank on their pneumatic guns, an example being their "Dark side Predathor". I once thought a carbon fibre tank gun may pose problems in being airtight, but apparently not as I have not heard anything negative about those guns. Sporasub have their "One Air" which might benefit from a carbon tank as it may not then need a nose cone float.

    Edited once, last by popgun pete: added cone, as in nose cone float ().

  • A dual power "Dreamair" is a possibility using the twin axle version of the muzzle shown here. In such a gun each wishbone draw would move the piston half way up the gun barrel. Hence for full power you would cock both wishbones, "half power" you would only cock one wishbone.

    How many people would be interested in that version I wonder and whether they would find it useful.


    P.S. I just discussed this with the inventor and he says the intention is to run any future twin axle gun at 22 atm start pressure, not the 11 atm of the single axle gun which will be available first in carbon fiber. Note that with a completely sealed pressure system the pressure being stated is absolute pressure as the "Dreamair" is not affected by ambient pressure at depth. That means you pump the single and twin axle guns up to 10 atm and 21 atm respectively using gauge pressures. The partial vacuum created in the rear of the gun as the piston is dragged forwards during cocking is why you need to think in atm absolute terms when doing force calculations in order to determine the gun's power and how much effort will be required to cock it.

    With a compression ratio of approximately 2.0 the gun will reach 22 atm (single axle) and 44 atm (twin axle) with the piston fully advanced in the barrel bore. According to my calculations the twin axle gun will be at 29.3 atm after the first wishbone draw, hence that will be the start pressure for the next wishbone draw. The attached diagram indicates how this was calculated, the effective compression ratio being 1.33 on the first draw. As start pressure is 22 atm, the pressure is given by 1.33 x 22 which equals 29.3 atm. The area under the graph represents the amount of energy stored in the gun, note that it is not a simple straight line, but a shallow curve. This is because pressure P x volume V is a constant for a given quantity of gas and thus P is inversely proportional to volume changes or mathematically P x V = K (a constant) and therefore P = K/V which can be represented in graphical form as the familiar inverse function Y= 1/X.


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