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Fishing/Bait launcher Pneumatic cannon

Posted: Mon Jan 23, 2012 8:41 pm
by hash
Ok so i need a little help. I live in so cal and do a bit of shore and pier fishing, and one of the problems is casting. weather its casting a heavy weight for shark fishing or casting a light swim bait for bass and such u never seem to get enough distance. So what i want to build is a simple straight tube system that can be broke down at the valve in two pieces the 1)barrel 2)valve and tank. I was thinking of using a 2" dia pvc for the barrel and using either a water dissolvable case or a floating one to wrap the item so it seals in the barrel. i wanna be able to launch from about 1 oz of weight up to about 10 oz of weight. one of my main concerns is the barrel exploding because its to heavy a load, another issue is the line, if it launches and the line isnt traveling right it could snap. I know wrapping pvc is a preventive measure but i would like to put a slit about halfway down the barrel from the tip to allow the line to travel with the projectile. I already have a basic spud cannon design i was gonna use but if some one can provide me one they have for launching lines or such i could adapt that would be great. because the other part i need help with is calculating if i put W weight with P psi in the tank and A angle it will launch y feet (y=W*P*A)<i know thats not the formula but thats what i need in laymans terms. thanks for any input guys

Posted: Mon Jan 23, 2012 8:45 pm
by Proxywars
Um what I don't understand is you want to launch the bait and line but how are u going to get it onto the reel? Or do you need info on that to?

Posted: Mon Jan 23, 2012 9:05 pm
by hash
No.the fishing line would be attached to the reel ran thru the eyelets on the rodthen attached to a weight loaded in the spud gun then launched while in free spool. I guess u could say my questions are would my barrel support a 10oz weight at say 120 psi by it self and or with a vertical slice half way down. And could I calculate where my projectile will land if I have the weight, psi, angle, what's the formula. In laymans terms I'm fairly good at math but remembering physics is a bit of a hassle.

Posted: Mon Jan 23, 2012 9:15 pm
by Gun Freak
The barrel would probably be able to handle it. A metal (copper for example) would be safer and stronger. You'd need a lot of pressure to launch a 10oz weight and the recoil would probably be pretty gnarly. Make sure your reel has good free spool. I'm assuming its a spinner?

Posted: Mon Jan 23, 2012 9:26 pm
by hash
Well I have one spinner id use with a system like this but not for anything large. As far as the heavy stuff I have bait casters that I can thumb. The largest weight I use is 6.5oz plus a chunk of squid and the case might make 7oz I just like to have extra room to wiggle if needed. And for using a metal barrel how would u connect that to a pvc air tank, or use a metal tank too. I wanna build it myself because I don't wanna pay hundreds of dollars for a bait launcher.

Posted: Mon Jan 23, 2012 9:32 pm
by Gun Freak
The projectile (weight and bait in this case) would be going pretty fast. So, you may normally be able to thumb the baitcaster, but if you launch it, I think it'd spaghetti pretty easily. Sometimes spinners can even get caught up in a rapid free spool. I think this is a bad idea given the intended weight. Doesn't seem practical either. Maybe a slingshot :D

Posted: Mon Jan 23, 2012 9:47 pm
by hash
Well its mainly the lighter swimmer baits I need to go that far. For the heavier weight id like to add maybe 50-75ft to my cast. Making it maybe 150-200ft out. I've seen some available for this purpose witth specialy designed bait holders that can go 300+meters with up to a one pound bait.(not my stats just what was claimed by the sellers) using bait caster reels. I planned on playing with it in the field and expect to break and tangle some line dialing it in but hope for the most part a smooth operation. Just looking towards the experts for tips and advice.

Posted: Mon Jan 23, 2012 9:59 pm
by Gun Freak
For the light bates, it might work. But...
You'd need a sabot, because of the treble hooks. And since you'd be shooting in water, you want the sabot to be retrievable. If you make a light weight plastic sabot, you can tie a line to it (maybe some liter or wire) and secure the other end to the cannon, so the sabot can push out the lure but not be shot in the water, because the line would hold it back. I'd make said line about 10 feet long so it wouldn't bouce back after the shot. Only problem I can think of is the sabot retaining line might get caught up with the lure's treble hooks.

You might instead be able to use a captive piston... Essentially a sabot that doesn't exit the barrel.

Posted: Mon Jan 23, 2012 10:10 pm
by hash
So I'm guessing a sabot is a small disk or wadding of sorts to keep the pressure behind the projectile until exiting the barrel. And for the most part I use single hooks. Only a couple tadys and rapalas have trebles and I only really use those on the boat.

Posted: Mon Jan 23, 2012 10:14 pm
by Gun Freak
In this case a sabot could simply be a plastic disc that fits nicely in the barrel to fire weird projectiles.

Ok sorry, by swim baits I assumed treble hooks, you mean the rubber ones? Let's get on the same page here about bait before we go further :P do you live in the southeast? Florida perhaps?

Posted: Mon Jan 23, 2012 10:25 pm
by hash
Yes I do mean the soft rubber swim baits, I don't get bites on hard baits from the pier. And I live in san diego, ca.

Posted: Mon Jan 23, 2012 10:32 pm
by Gun Freak
Ah, ok, ok. So since you're shooting rubber baits, there is going to be massive friction in the barrel. I think a paper cup-shaped wadding will do well. But I still think the idea is a bit impractical. You would have to pump up every shot... And for a swim bait that would get annoying...

Posted: Mon Jan 23, 2012 10:44 pm
by hash
Well for pressureizing the chamber I plan on using a small battery compresser. And that was part of the reason for the bait launching capsupe. The one company I saw had one that split in half when it hit the water. Bio degradable ones and ones that remained around the line and was reusable.

Posted: Mon Jan 23, 2012 11:05 pm
by Gun Freak
Even then I see the idea impractical. I never find myself unable to cast where I need to because of distance. But it may be different in San Diego.

Posted: Mon Jan 23, 2012 11:10 pm
by hash
Well some piers can be a bit windy and all but a select few places you can't overhand cast. Side casting is worse imo and you can't really underhand a saltwater baitcaster.