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Different setups performance
- Thread startertromic
- Start date
Thread Status: Hello
, There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
It can take a long time to get an up-to-date response or contact with relevant users.
I also tried the best to worse. Because I can not upload the picture (I exceed the limit of attachment):
1 is Tomba slider and 1 mm mono.
2 is Tomba slider and 1,5 mm mono.
3. is Tomba slider and black nylon rope.
4. is Mares slider and black nylon rope.
1 is Tomba slider and 1 mm mono.
2 is Tomba slider and 1,5 mm mono.
3. is Tomba slider and black nylon rope.
4. is Mares slider and black nylon rope.
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Interesting conclusion could be made from data on the link:
http://forums.deeperblue.com/pneumatic-spearguns/91753-different-setups-performance.html#post854027
Best "free shaft", fig. 11, is about 49% better in energy of the shaft on the target than the slider version of system using devoto line slide. That means that any vacuum barrel system using devoto like line slider is inferior to "free shaft". The exception is tomba plastic line slider, fig 4 and 12, that is same or better in energy on the target than the best "free shaft".
One can see a gun range (Cyrano 850) at 25 bar with a 7 mm shaft and vacuum systems:
According to Figure 19, with black nylon rope and the original mares slider - about 2.8 m.
According to Figure 18, with black rope and Tomba slider - about 3.3 m.
According to Figure 17, with mono 1.5 mm, and Tomba slider - about 4.6 m.
According to Figure 4, with a mono 1 mm and Tomba slider - about 5.2 m.
I took the lowest speed to be 10 m/s at which the energy of the shaft is around 16 J. I also took for starting speed the speed after shaft exit from gun 1 m (length of shaft). Is 10 m/s enough? It's as if you would shot from the same gun inflated to 2.5 bar into air at a target located 1 m from the tip of the shaft.
According to Figure 19, with black nylon rope and the original mares slider - about 2.8 m.
According to Figure 18, with black rope and Tomba slider - about 3.3 m.
According to Figure 17, with mono 1.5 mm, and Tomba slider - about 4.6 m.
According to Figure 4, with a mono 1 mm and Tomba slider - about 5.2 m.
I took the lowest speed to be 10 m/s at which the energy of the shaft is around 16 J. I also took for starting speed the speed after shaft exit from gun 1 m (length of shaft). Is 10 m/s enough? It's as if you would shot from the same gun inflated to 2.5 bar into air at a target located 1 m from the tip of the shaft.
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Hi
Unexpectedly the high-speed of harpoon(staff) turned out for me.!!!
It would be very interesting to get results for Cyrano 850 without a vacuum system...
alex
Unexpectedly the high-speed of harpoon(staff) turned out for me.!!!
It would be very interesting to get results for Cyrano 850 without a vacuum system...
alex
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I already made that measurement last year and year before. With vacuum barrel gun the energy of the shaft is about 25% higher than with water barrel, on depth just below the surface. Deeper it is more than 25%.
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Thus, your gun without a vacuum has initial velocity of harpoon of approximately 26 m/s ???
Seems look like truth.... of
alex
Thus, your gun without a vacuum has initial velocity of harpoon of approximately 26 m/s ???
Seems look like truth.... of
alex
Not 26 m/s. About 29.5 m/s. Vacuum barrel is about 25% better than water barrel in energy, not in speed.
Yes. correctly...excuse me
(V1)*2 /( V2)*2 =1,25, means on speed harpoons difference in12 %
Yes. correctly...excuse me
(V1)^2 /( V2)^2 =1.25, means on speed harpoons difference in12 %
Yes, SQRT(1.25) = 1.118, that is about 12% higher speed with vacuum barrel.
Dai risultati di energia ottenuta con 1 mm e 1,5 mm mono possiamo vedere che l'albero ha più energia del 33% con 1 mm mono, sulla stessa distanza, che con 1,5 mm mono. Ciò significa che con 1,5 mm mono la pistola dovrebbe essere sul 33 bar per avere le stesse prestazioni (energia) e con 1 mm mono a 25 bar.
Per il confronto sono il presente che il beneficio del barile vuoto su barile di acqua è circa il 25%.
From the results for obtained energy with 1 mm and 1.5 mm mono we can see that the shaft has 33 % more energy with 1 mm mono, on same distance, than with 1.5 mm mono. That means that with 1.5 mm mono the gun should be on 33 bar to have same performance (energy) as with 1 mm mono on 25 bar.
For comparison have on mind that the benefit of vacuum barrel over water barrel is about 25 %.
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How pressure in gun affects effective range. In this example Cyrano 1100 was on 22 bar with 6.5 mm shaft and the range was about 5.6 m. How much more pressure is needed for longer range? 29 bar for 6.11 m. Even 36 bar would be neccesary for 6.5 m.
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Just stumbled upon this Tromic - v.interesting.
I'm using a kara-yo tovarich with 2mm Dyneema.
I must admit i've not tried mono, but if I use anything less than 1.8 or 2mm dyneema, it tends to tangle when the gun is fired - I don't use a reel.
Any thoughts?
I'm using a kara-yo tovarich with 2mm Dyneema.
I must admit i've not tried mono, but if I use anything less than 1.8 or 2mm dyneema, it tends to tangle when the gun is fired - I don't use a reel.
Any thoughts?
It would be much better with 1,5 mm mono and a reel. Do you use micro slider with free shaft?
just a free shaft - i've got a micro slider but I don't use it. I have it at 20bar.
The shaft flies true without a slider i've found (although I havent tried a reel) , and I can take some pretty long shots with the gun.
I also don't think I like the idea of having the whole spear assembly with micro slider passing right through the fish and then having to deal with that each time I shoot one.
With so much power the whole spear goes through atm, and sometimes it can be a pain to thread back through especially with double flopper and a lengthways shot on a fish.
heres how it looks atm
How do your reel assemblies look then?
The shaft flies true without a slider i've found (although I havent tried a reel) , and I can take some pretty long shots with the gun.
I also don't think I like the idea of having the whole spear assembly with micro slider passing right through the fish and then having to deal with that each time I shoot one.
With so much power the whole spear goes through atm, and sometimes it can be a pain to thread back through especially with double flopper and a lengthways shot on a fish.
heres how it looks atm
How do your reel assemblies look then?
Ok, thanks for the picture. It is OK, but just try with a mono. It would be better. It is even better with a micro slider but is not so clean, simple. If you use a thin mono (1 mm) from the tip of the shaft to the slider and than 1,5 mm (or 2 mm) from slider to the gun it would be even better than with 2 mm spectra. You tie the mono, after 3 wraps, to some line (50 m) used for the reel.
Foxfish uses the same setup like you but with mono: http://forums.deeperblue.com/pneumatic-spearguns/91007-measuring-speed-shaft-3.html#post854223
Foxfish uses the same setup like you but with mono: http://forums.deeperblue.com/pneumatic-spearguns/91007-measuring-speed-shaft-3.html#post854223
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