Posts by Diving gecko

Quote from Don Paul

I hope those Bubble butts loose all their gun power.:bs2:

Cheers, Don

Man, here in China internet speeds can be pretty slow, so when I feel like watching youtube spearo videos I often just bulk download a batch of them based on their titles and watch them later. I absolutely hate when a bubble blower one sneaks in.
I have changed my stance on commercial spearing, though. I think it is OK for them. Except for one video I came across of a dude sitting on a wreck shooting big AJs with bangsticks... The fish would come right up to him and he would blow their brains out and it would just drop next to him. Then after a while he would swim around and collect the 'bodies' and head up...
On the other hand, I guess it is not much different than a slaughterhouse, it just looks off when it is in the wild.

Anyways, I digress.

I have been trying to find a pic of a Bazooka for you from a friend in Denmark who sacrilegious added carbon fiber reservoirs to his:D. I'll ask him for it and post it here, if I get it:-)

Quote from Dan

Ha! I have an extra yellow cargo strap, now I know what I'm going to do with it :thumbsup5:

Some scuba divers go deep to shoot fish. At 40 meters I'm told the power loss is significant, going deeper than that the gun gradually becomes useless.

True, I did give scuba hunters a brief thought, but then again, I don't care much for them, so didn't go into it.
Again, if my math holds true, then 40 meters should result in a pressure differential of 4bar and as such ((4/25) x 100) a 16% power loss on a 25 bar gun. 50m would give a 20% loss. But again, if the gun is more powerful than a band gun to start with, I do think the loss is not a huge issue (unless it aims vastly different with depth). But a commercial scuba spearo would have so much water time, he would get used to that.

Here's a Corsican deep freedive spearo who uses pneumatics (they are crazy pimped, though). He is quite "Forza ME, ME, ME!" but his skills are pretty mad, so I still enjoy his vids:

https://youtu.be/-t_yuLirUiA

Quote from Dan

Which reminds of one disadvantage of pneumatics, they lose power at depth.

Quote from Marco

Negligible. 2 atm at 30 meters. I can live with that. Here in Panama is very rare to dive deeper that 15 meters. There's no visibility. I'm not sure, but I've read that bands also loose power at depth. Is that true?
[...]

Yes, I was about to call Dan's comment "cute";)
Strictly speaking, Dan is right of course, they do loose power, but nothing major unless you dive very deep.

Not sure if it is 2 bar loss at 30m or 3 bar. Maybe Pete can help on that one. I would think it would be 1 bar per 10m. No need to count the 1 bar for atmospheric pressure at the surface as that would act on the gun, too (I think).
If my math is correct, Marco looses 1.5 bar of power at his max depth which is a 6% loss as his gun is loaded at 25 bar. So, yes - negligible.

in reg. to bands, I have heard such a thing as "band soak" or similar exists in bandguns;-). I think I have heard numbers of about 15% loss of rubber force with prolonged loading times. Actually, I could test that as I have whacked together a test bench for breaking lines and such. Supposedly, bands loose power with a lower temps, too which can be noticed by spearos diving in the cold waters.

The before mentioned test bench; scale goes to 300kg, ratchet strap thingmajing to more:

It's a neoprene sleeve. Quite common in Italy - and I think I see the logo from one of the Italian shops printed on one of the sleeves, too;-)
It helps with buoyancy, too (obviously not at depth).
(Neossub)

Man, that's the best oleo post I think I have ever seen. No BS, just the pics:-)

Mares should refund you the money you gave them and send you a Xmas card, haha.

Beautiful fish, thanks!

[EDIT]
Come to think about it, I am beginning to think oleos are cheaper to run in the long term - the no nonsense ones, that is. Air costs a whole lot less than new rubbers. And an o-ring set is less than 10 bucks. I started with airguns and only getting slowly into bandguns now, but of course I felt like I had to immediately run out and get fancy rubbers for that;-).

I have been thinking about magnets, too as I know they are used in some open muzzles. And some guys even splice one into their slip-tip line. But I got a bit dissuaded when the magnet I had in a line release for a pneumatic gun withered away after the first spearing trip. What do you guys do? Epoxy coat your magnets? Rubber coat them?

Quote from popgun pete

[...]Today there is talk of teething problems and guns being sorted out with a need to be patient as the fixes come through. In the early days guns with even a hint of trouble were dropped like a hot rock and never considered again, so new guns were only let out after all bugs had gone. Now the need is for a procession of new models every few years and the development time is just not there, so "beta test" guns get sold to the public.
[...]

I very much agree, we def have a few cases in point right here on this very thread - One Air and the new Evo. Predathor had crappy slider, less but still an issue (have been rectified now, supposedly).

Dan is right in that there aren't much difference at all between new and old in traditional oleos like these.

Personally, I will say this about the two examples mentioned. The Seac Asso has the strongest trigger pull of pretty much all the off-the-shelf guns being sold these days (maybe a few more with ol'skool 3mm triggers out there; Cressi SL?). Enough of a reason for me to rule it out for non-tinkerers (it is a 15-20E modification, if you can get the parts and feel like doing the swap). The old Cyrano, which I have never shot, is said to be nose heavy on account of the slimmed down nose.
Personally, balance and a smooth trigger pull are the two exact things, I care the most about in these guns since most other things are equal - so though they are tiny improvements I do think they are worthwhile in newer guns.
That said, 30 year old Stens, Jets, Tiguilios, etc should all shoot as powerful as a 2017 Sten today. (Oh, I forgot, as Pete mentioned, that escape holes in the muzzles have possibly been bettered. Again, go nuts at home with a dremel and you should be up there with the newer ones).

I do hope and expect Mares got the balance right when going with hydroformed barrels on the new Evo, but it could be more bling than practically needed. Or perhaps half/half (a friend in Denmark has one, he feels it balances beautifully).
The insides work exactly as a Sten did for decades though one day, it would be good to verify if the bigger transfer port through the bulkhead is an actually improvement or just sales-speak. That would imply that the traditional 6mm port hole would be throttling the air flow and I don't know if that is the case.

In reg. to the One Air, I have one and I agree that it fails to impress when looking at it in real life. It's a job half done for sure. Just the way the nose cone intersects with the barrel looks like an afterthought. The handle could be the best feeling of any mass produced airgun though its design robs the gun of efficient "band stretch" and its line release is a bit retarded, too. But the gun just shoots so clean and smoothly on account of its bulk. So, while I like how it shoots, I have never fallen totally in love with it.

(There is one thing we didn't mention this time when it comes to the Predathor. It is the best priced for a dry barrel gun. A Sten would need an E40 muzzle and often times a new E20-25 spear to be directly comparable and would end up quite a bit more expensive.)

Yes, it is indeed a lame name, well the spelling part:-).
Their carbon fiber pimped Predathor is called Dark Side, haha;-)
(But at least that cudos to airgun afficionados as they are often referred to as having gone to the dark side).

I think there are always people talking shit about most of the big brands, oftentimes warranted, of course. Pathos is on a roll, but I have seen people complain about e.g. their reels and you hated their foot pockets, right? (1000s of freedivers don't, btw). But in general, it seems as many happy/unhappy Salvi users as with most other big brands, no? I get that their first generation of guns supposedly had some issues (muzzle design for example) but is the whole catalog seriously shit or are you just being harsh? Is everything breaking? I'm genuinely curious:-).

So far my own few products from them have been totally fine: I have two suits from them, no issues with them whereas the one I have from Omer is a total frikkin dud coming apart in all seams from the very first dive, their Atoll float, too and I have seen two of their Mini Laser (?) knives snap at the root of the blade. Still, a lot of love for that brand out there so obviously mileage varies and I did like my Omer Stingrays before I changed to Pathos pockets.
I love Salvi's ST knife and I don't expect issues with the Predathor based on quite a number of them being used by spearos back home and none have complained (just don't use the original line slider! But at least they changed it now - just like they changed their 1st generation open muzzle quite fast).
BTW, they just incorporated a roller in the trigger mech of their newest bandguns. If it is well-executed that could possibly be a step up from all(?) pipe gun manufacturers in terms of triggers.
I have a Pathos handle and an Omer Cayman handle next to me right now, and I can flex the Cayman handle with my bare hands, a lot less so with the Pathos but there's gotta be 1000s of Caymans out there. I don't have a Salvi bandgun handle but the plastic on the Predathor and the handle itself has to be some of the toughest I have even seen (I hope it is not brittle).

Hey Marco,
Thanks so much for the info - I will add it over there, if you don't mind.

I think the discussion Pete and I had started when I assumed most of us always pre-charge our guns close to the max we can load and I thought he did, too. As such, I got really confused with the 62%, too and then things went overboard;-)
But the whole thread got me thinking about that exact point and I find it really interesting what people can load.

BTW, I wanted to PM you - but I might as well tell you here. I might be having a few 1.4-1.5mm trigger sets made for Predathors. If I succeed in having them made and they hold air, I'll find a way to get you a set:-). It should reduce the trigger pull by 350g-400g at 25 bar but you still have spring tension and a bit of friction to contend with.

I placed the Predathor trigger on top of a Mares Mirage trigger and the geometry is the same, so the leverage should be, too. But I don't know if they changed the geometry of the Evo - they might have in the 30-40 years since the Mirage, haha. Maybe the Predathor springs are really strong. I will check on that in a few days and try to make some comparisons to other springs I have here.

Hey Marco,
I have just begun trying to "poll" a bit over here about the pressures spearos tend to run their guns at.
I can't recall if you are a member on deeperblue but if not, I would love if you could give me the skinny here:
What pressure do you run your gun at? And do you pressurize it to the max you can load or?

BTW, didn't you get a Predathor 115/130 or was that for a friend?

While I personally have a lot of respect for deep spearos, I agree that 60m is extreme. 30-40m is still very deep for spearing but more manageable for more spearos. It's always hard to have to set rules like these, but maybe you could say max 40m... I don't know. Again, in sailing we sometimes had races called off when the organizers felt it was too windy. We had trained more than most in in our class in strong winds to make up for being a light crew, so we often felt a bit "cheated" not to get the chance to go out and score some good points - the bigger guys even more so.

Maybe CMAS or others could make a special 'deep championship' some day. Maybe for two-diver teams with one gun per team in the water at the time, so the buddy can only act as safety. But soon it will be like boxing with too many championships, so I still prefer a deep location for a proper WC once a while, though less extreme and better managed than what Ramon reports.

To the first part of your question: I have searched for the past 20 mins because it is is an interesting question and I know I have seen designs like this before but can't find them again. Maybe from an Italian who experimented with it. I would think, Pete might have something bookmarked. In the meantime, I will keep searching.
I guess the new DreamAir can be said to have eccentric loading and power delivery though not with cams and rubbers but with air pressure and conical rollers, but tapping into the same idea of redestributing the force curve.

And I also agree that in the context of bows, 'compound' infers the use of a cam. I just happen to think you can use the same term in a speargun without using eccentric cams, without non-linear force distribution and without it being a misused term:-).
(If this website can be believed then there is such a thing as 'compound pulley systems' without any cams and without any change in speed or loading effort: Rope Rescue Calculating MA by Counting the Lines)

That's a good question and probably someone (maybe in the Med) has made some protos of what you call a 'true compound' but generally, the term indeed seems to sometimes be used for any pulley/polispast/demultiplied gun like you suspected.

Another question, and very much one of semantics, is whether the word 'compound' can be said to necessarily have to have anything to do with eccentric cams? In general, compound just means "two or more parts". Maybe in physics, it means something about a non-linear force delivery as in your eccentric pulleys? I am far from certain but I don't think so. Will be interesting if someone knows the answer:-).

But the more I think about it, the more I tend to think 'compound' can not be said to equal the eccentric cams parts of a bow. Maybe compound in a bow is the use of both pulleys and cams and maybe the bow folks kinda just annexed the word.

And maybe the spearo people didn't even think of compound guns when they started using the term, as there is such a thing as a compound pulley system already - which I guess is as close to home for a pulley gun as a bow is to a speargun.
In a mechanical pulley system - as with ropes and pulleys - I think the word 'compound' is used to define a special mix of pulleys where the tag line of the main sysem has another system of pulleys acting on it (again, two or more parts). I can't explain it well, sorry:-(

Now, a lot of pulley guns are actually just straight pulley systems, so maybe it is wrong to call some of them compounds but perhaps not because they are lacking eccentrics cams:D;)

Quote from mosaad

how much the 403 filler 150 gram can give you epoxy to mayonnaise shape? I mean 150 gram fiber = X mL mayonnaise epoxy ?
my question for estimate the quantity I need to purchase online

From the data sheet:[INDENT]
A one-to-one addition of 403 Microfibre Blend (in terms of bulk volume) to WEST SYSTEM resin/Hardener mix, is suitable to produce a structural adhesive for wood
[/INDENT]

http://www.westsystem.com.au/f….fillers/403_mf_blend.pdf

Quote from Marco

The organizing country sets the competition area. And they want to favor their athletes.

A couple years ago it was in Portugal, where spearos had to dive in 3 feet of water with 15 feet waves! And it was won by a chilean...

Pedro Carbonell form Spain won three world championships (Gijón 1996), (Tahití 2000), (Brazil 2002). Every place was totally different.

Just my 2 cents...

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Like I said, most often, the best guy wins. (That is, the best guy on the day in those circumstances;-)).
What I like about the big sailing championships are that we often had two races a day for 4-5 days sometimes with a rest day in-between. So, chances are we will experience more different conditions and the "risk" of a specialist winning it gets reduced and so does the impact of a bad race or a material failure.

If spearfishing teams spend a lot of money to go to Lima, Peru, or Europe for a Championship I fail to understand why they only compete for two days? Yes, they have work and families to go home to and yes, organizers are probably unpaid. But that's exactly the same as in sailing and while our regular regattas are only a two-day weekend affair our WCs are much longer. If sailors can do it, so should spearos be able to.
Three-four days of competition would also afford more options to hit different locations and mix and match the conditions, so the overall winner would the best over a wider range of conditions.

BTW, congratulations to the awesome deep divers of Greece and Cyprus:)

Try checking out some of the deep divers youtube channels, you'll see some real skills involved.
I can recommend Anvar's channel, talk about a love for spearfishing:-)
https://www.youtube.com/watch?v=uWd1FOcwrGM

Manolis seems like a really nice guy, too:
https://www.youtube.com/watch?v=aCKOan-b41g

And I wanna be a cool as Dimitris Kollias [/URL]when I grow older:
https://www.youtube.com/watch?v=LAiPrfFhrSw&t=12s

Sorry for taking focus away from how tragically flawed deep diving is, but Xmas is approaching, let's rejoice and reach out;-)

Quote from Peripatetic

My point was that math can get you close, but knowing roughly the specific gravity of the blank, you can build the gun you want, and adjust buoyancy to fit the exact properties of your gun.

And my point is that if you are using only one type you don't need to settle for "roughly":). You can measure the size and weight of a piece of the wood you are using and obtain the exact density of that wood. It would take about a minute. Unless the density changes within your batch, then you will have very good numbers to work with.
So, in terms of buoyancy you should be able to get it pretty much perfectly neutral without even having access to water.

Now, fore and aft balance let think about that one. Perhaps, it is a simple as balancing the rigged up gun on a "knife's edge" and moving the lead around until the gun is level. The gun as a whole, with the ballast, should have the same density as water so this might just work. Now, if you want to dial in any nose heaviness, I guess that's for the pool. Overall, I still think you can get extremely close in your workshop:)

Hmm, I have never competed in spearfishing and probably wont. But I used to race sailboats a whole lot and the dilemma is sometimes the same, perhaps to less of an extent.

Especially in the one design dinghies such as Laser or Finn the weight of the sailor plays quite a big role. As such, some guys have an advantage e.g. in predominantly light air if they are light. Sometimes big championships are placed in a location that are predominantly light or heavy winds. And some sailors will have the upper hand. Mind you, tactics and skills can even the playing field a bit and also it can blow at light wind locations. Also, our championship regattas are spread out over more days which evens the playing field a bit more.

Same with the Tour De France or other cycling events. The location, the route, the terrain often have an influence on what type of rider who can win. Even the WC in cycling is like this. Sometimes the sprinters are favored, some times the climbers. Is it fair? I don't know. But you rarely hear people moan about it. They just do as well as they can and hope for a better chance next year.

My point is, apart from the safety issue here, why get so worked up if just once in a while over the course of many, many years a championship is placed where deep divers are favored?
Some of you even make it sound like this had nothing to do with hunting but only deep diving? Personally, I wouldn't know but after making it to the deep, you still need to find, stalk, ambush the fish, place your shot and land the fish, right? I personally think there is both hunting and apnea skills involved in deep spearing.
There has been plenty of shallow reef tournaments over the years where people have pulled out huge, disgusting eels and dozens of tiny breams to win, no? That's surely a skill, too but just once in a while, I think it is OK to honor other skill sets. There was championships before this deep one and there will be many others after. Things will even themselves out and the deep divers may not win again for the next 5-10 years. Maybe in a few years, you'll drop divers miles in out bluewater looking for wahoo and whatnot - and then the reef guys will start complaining. Sports were never fair, could never satisfy everyone and oddly enough, we like them and the best guys on the day tend to win.

So, apart from the safety issues here that needs to be figured out, give some credit to the winners and then go and prepare your team for next year or the year after. And perhaps praise your luck if you happen to live in a place where you don't have to dive deep to get fish;-)

[EDIT]
I just re-read Ramon's scathing write-up. Sounds like a lot of issues at the venue. But my main point still stands. Once in a while, I would think a deep location is fine. Maybe not 60m and of course with proper safety and such.

Quote from Silentstoning

Holy hell Diving gecko, you are a math genius. Thank you for that. Is it tried and true?

Only tried in my mind...:@:D
So, I am really hoping that some of the engineers or math guys here will double check it. Pete could see through any issues with the method in a split sec so let's hope he chimes in:-). That said, I am sure enough of the math that I would use it myself for what it is worth;-)

I am landlocked, but without a workshop and have a quarter of an engineer stuck inside my photographer's body longing to get out - furthermore, I have too much time on my hands sometimes so I tend to have to solve spearing puzzles in my mind way more than in real life, haha.

I am sure some of my points were more theoretical than a real life issue. Could be so with the band contraction. But on some level there has to be some energy loss when the bands have to move through water themselves during the shot. I was just pointing out that the "engine" of a pneumatic is internal and there is not much drag on it.
I don't know if there's a real world difference in it, though.

I actually haven't shot many band guns and yes, you are right - I was making the comparison to a pipe gun;-). It's a good question about recoil of two equally heavy guns, though. I would say that if spear has the same mass and the band gun is a regular band gun without some sort of recoil cancellation or recoil reducing setup (like a roller, inverted roller, pulley, etc) then the pneumatic should have less recoil because less mass moves during the shot. Unless of course it really shoots a whole lot faster so that recoil starts increasing.