Frankengun

[SASpearo]

I'm going to have some serious time on my hands in the next couple of months, as well as access to a very well equiped workshop ....

Now the problem is it's far from divable water. So, I plan to build a frankengun ..... YEAH!

I'm thinking along the lines of a 180cm teak gun, with rail / enclosed track, couple of interesting ideas around the setup of the rubbers ...

What would be a very cool Frankengun?

 

[Griff]

You know what always works

incorperate a audio player that plays the mating calls of whatever fish you are after . but be careful, you may still attract some excited divers with very strange preferences rofl

good luck

mark

 

[SASpearo]

Mwaa ha ha !

No, seriously ...

I'm looking at a serious Teak pole, aroun 150cm to 180 cm, Either a riffe or Wong mech, home - made fibreglass handle, then probable an enclosed track .....

The rubbers would be the main thing now - I've got a couple of ideas, not too well formed at the moment, but all designed to make maximum use of the rubber ...

I was thinking of looping the rubber at the muzzle end, so that most of the rubber runs underneath the gun, and once fired, the wishbone would run all the way to the end of the track, there slamming into some form of butt plate or something - you'd get full use of the length of the track, as well as ensuring that you use the full length of the rubber.

At the bottom end of the gun, I'd put a 'cocking' mechanism - a kind of fold - out arm that secures the back end of the rubber, so when you fold this arm out (making an approriate V sign) the rubbers would be slack .... I don't know if I'll be able to fix it so that you can load the rubbers in this position, but if you can you can pour more power into it - as hard as a RA to load, and then (with a cam - type action on the front of the arm) get a bit more oomph ..... of course this would have to be strong enough to handle 4 to 8 20mm rubbers .....

Mmmmmm .......

 

[Iyadiver]

SA

I assumed you are talking of a wood working shop ?

If it does not have the bits for making the enclosed track, this might cost you some money for a one-off project.

If you want a long gun, I advice you to use laminated construction. Not only it will be easier to source thin wood but in actual fact lamination allows wood "fiber" to be oriented in opposite direction and allows even shrinking and expansion. This will also be good 4 strength because wood is very strong in one direction. I have books from West System (USA), the epoxy people, they tell a lot about wood as engineering material.... amazing data. In fact I have plenty of books on fiberglassing wood, if u need any data I will surely help.

For your pistol grip, maybe you want to take a look at certain target rifle adjustable pistol grip design. They can be adjusted to a specific palm size and the feel & grip is fantastic, I never seen one in a speargun before because they are expensive. If ur is custom why not go all out.

Just in case u want to ballast the gun, I am sure you would, there is a special recoil absorber that shotgun people use, I think it is a like a small cylinder that contains mercury. The idea is to allow the mercury weight shift to absorb some recoil, I don't know how exactly it work

Maybe if you are innovative enough you can use a shock absorbing pistol grip that moves say 2-3 inch during a shot ( with some sort of rail ) in order to absorb the recoil, I am still thinking of how the hell to design such thing. Big artillery I think use this system. :duh So the recoil engery is spent pushing the gun rearward instead of breaking arms, less ballast, smaller gun faster swing................. in theory. ha ha ha.

Have Fun
IYA

 

[SASpearo]

I've seen the mercury weigths b4 ...

They're pretty cool - bloody expensive though ....

How about making a sliding barrel? Like you see on the SA G5 and G6 cannons .... mmmm

The whole barrel is movable, once a shot is fired the barrel moves back to counter recoil .... shees, that would be a mission to build though.

I've got most of the tools for mfting an eclosed track, would probably have to shell out for the right router bit though ... wouldn't be too expensive.

I've been having a look at some monster guns on the 'net, and came accross some 'rollergun' designs .... that's gonna be incorporated into Frankengun for sure !

 

[SASpearo]

Another thought ...

brainfart ...

How about making a sliding lead weight balast system? Basically a sealed tube with a well - fitting lead weight inside, along with some oil for lube .....

Incorporate this into the barrel .... voila!

 

[Iyadiver]

YEP, I seen the roller gun from Uncle Jack Prodo, I think max rubber strecth can be a reality from this design. Just make sure the wood can handle the ripping force. Wood is very good if u load them by compression but it you attach like 4-5 of 14mm rubber pressure other than against the grain..........mmmhhmmm I don't know if it can take it.

I been brainfarting for so long on how to remove recoil from a speargun. Ur sliding lead in oil could be the partial solution.

The pistol grip stays when shot while the stock/barrel move is another word of explaining a sliding barrel. We have this barrel assembly on rail design in high power airgun, they work but the recoil involved there is only like 2x14mm rubber equivalent.
The problem of sliding pistol grip will be the trigger, it means you must have a push rod that can play along with the movement. I imagine a mini hydraulic hose being the method of trigger push delivery, like a boat trim tab hydraulic mini hoses. A push pull boat throttle/tranmission cable is also another possibility.

I mean recoil is a big factor in accuracy destruction. Why go to primitive way of countering recoil with weight, I mean this is year 2002, there must be some other exotic way of doing it. I know more mechanicals means more problem but if it is ur own custom gun, you will go tru all the trouble to fix thing ursefl, we ain't selling them anyway.

This is supposed to be a blue water gun, that one important shot is all that matters, I think being on the high maintenance side is no big deal, you do have ur RA for everyday abuse.

Sorry SA, when it comes to dreaming............I do enjoy this.

IYA

 

[SASpearo]

OK. Time to call in the experts ...

Andrsn !!!! Build me a recoilless speargun !!!!

no, seriously, share some of your aero eng expertise with us on this one ......

 

[Iyadiver]

Yes Chief Anderson, do help please...

This is exactly why I posted "recoiless speargun" thread months ago cause I know this forum is full of smart dudes with enginering background, but ...but...but.....at least a pneumatic genius contacted me and another frankegun on this side of the globe is on its way to reality.

Come on people, help SA , this brain storming can be as fun as sex....:head ( I wish )

IYA

 

[Griff]

this man needs help!

Sorry Iya, but you need to clarify this. Do you wish that sex was as good as brainstorming??

 

[Iyadiver]

If sex is as good as brainstorming, sorry, sorry, if brainstorming give same pleasure as sex, then that is why I brain storm a lot .... Wha ha ha ha . Imagine which actress I thought I "stormed":naughty

 

[Abriapnea]

Guys ,
What on (insert god of preference) 's blue oceans do you want guns of such size for ?
Surely the attraction of spearing sportmanship lies in getting up close and personal with your chosen target ?
If you encounter a fish you can't make contact with using a reasonable length gun , it deserves to escape your attentions .
Obviously this is only my opinion , but I would rather improve my skill level than my gun's reach .
Confession : Just finished a big scuba course , my manager bought several rounds and I have no head for alcohol . I don't mean to sound sanctimonious (took me about 5 minutes to tap that word ) but I really feel that a gun of reasonable proportions should be sufficient for anyones needs .

 

[SASpearo]

Originally posted by SASpearo
I'm going to have some serious time on my hands in the next couple of months, as well as access to a very well equiped workshop ....

Now the problem is it's far from divable water. So, I plan to build a frankengun ..... YEAH!

'Nuff said ...

 

[Iyadiver]

Abri,

Well, I wish everything is all perfect. No offence intended. What makes the bright light from the electricity in ur place ............was not that a dream by Thomas Edison, candle was good enough then...why more improvement ?. If we stop dreaming of progress, we might be as well be dead. There is no such thing as enough......when is enough : enough ?

Each one of us has different skill level, is it fair to say that 16mm x 2 is all we can go for ? Depends............

If progress is not allowed, how come we upgraded ourself from a pole spear to a speargun ? Why do we use mask and fins, is that natural ? Adaptation comes in many forms but the desire to improve is what make us humans.

It is difficult 2 say that what u have is enough, what is the barometer that we judge our progress upon ?

Stalking technique is one that we must improve upon....... no doubt about it.............. but is it wrong if we use science to improve the catch ? Is it wrong that one is not born to be as powerful as other in terms of strength and endurance ? Is it my fault that my waters do not have as much fish as the waters u roam ?

If we are simply satisfied with what we have, u and I will be on a horse back instead of cars......pardon me, again no offence intended.

If a 16mm x 2 is good enough to catch all the fish we ever wanted, Greats like Steve Alexander, Jack Prodonovich and all the rest of the daring legends made a "Great" mistake of building a far-shooting tuna gun and took unnecessary risks in getting their sorry ass in great white infested waters. We should have told them : "Look guys.......good stalking is better than big guns."

Come on Abri, I am definitely not 10% of ur skill but I sure know how to dream on.............

 

[rigdvr]

Come on IYA...don't be shy, tell us how you REALLY feel. I mean damn, we're not mind readers!rofl

 

[icarus pacific]

gun 101

check it out... http://spearguns.netfirm.com/Spearguns.html

sven

 

[Abriapnea]

Hi Iya , that is a very plausible argument , I guess as usual it boils down to personal preference .
I have recently joined a group of spearo's called Retrosub where we use exactly those polespears and hawaiian slings you mentioned
I find the restrictions my 3 ft spear impose is best suited to the small stuff I find here .I would be too embarassed to use a gun .
Happy hunting .

 

[Murat]

Hahahahaa don`t let the Iya blame otherwise there will be a fire in the forms rofl

 

[Iyadiver]

Another speargun 101

SA,

U must check this site out if you have not. My pneumatic friend passed it on to me since you mentioned rollers. Much better info than Rockfish. Enjoy. I think the guy is also South Afrikan.

http://niko.bonitofreedive.org/



Abri,

I never tried pole spear. I tried a couple of shots on Hawaiian sling but damn how the hell u aim these things ? However, I once joined a local traditional fisherman for night spearing from a small dug out canoe in the shallow lagoon. They used kerosene lamp and speared from the surface, small sleeping reef fishes for meal. It takes practice to sort out the refraction.

I don't know if anyone ever done this in other parts of the world but here in Jakarta there is this little fish that live in mud lagoon, usually near the prawn hatchery. Lousy water, brackish type.
they are like gobbies, small 5" long & 1" thick at most. Good eating if cooked till very crispy, taste like fish crackers with some meat in it. This is my oldest brother favourite hobby because he has a small fish hatchery by the coast.

He doesn't shoot with a speargun, he shot them with my ultra accurate airgun. At low tide ( no water ) this fish pops out of the mud, only the head, so very small target. My brother hid some 25-30 meters away. My airgun is totaly silenced ( silencer for airgun is legal here but not in the US ), so they usually don't know what hit them. This gun uses 3000 psi scuba charged air reservoir. Shooting 11.8 grain 4.5mm lead pellet at 950 feet per second. One charge allows you 40 shots. By the time like 50 over fish are down, then he walks to the mud to collect them one by one. You can't collect the dead fish too often cause all the other gobbies will sink into the mud and it takes time for them to pop out again confidently. Who says you can't shoot a fish from 30 meters away



Come on people, this is a democratic forum, everyone can say what they want...as long as it is ......polite......no hard feelings...we are grown up ( some with kids ) Me a happy man as always....

 

[Murat]

I am wondering what is Iya`s airgun. 4.5mm 950 feet/second himm very nice. Scuba charged air reservior?. Is it same as CO2 gas tanks or you just connect your scuba oxygen tank to the airgun? :duh rofl