barrel and sperars proportions

[qazedx]

as you could have guessed I am makeing a spear gun. I was wondering if I have a 8mm barrel(spear track) and I want to make an enclosed gun what shuold the spear deamete should be? also if I have a 8mm rail and I want to make an open track gun what should speras deameter be? in aditon to this, could you tell me what kind of stainles steal shoul I use for rail/barrel and for the spear (number)? besides wich profile is better for enclosed gun?

P.S. sorry about all the mistakes and thank yuo for your anserws.

[metelin]

for an open track i use cutter thats 1/32'' larger, so for an 9/32'' shaft i use 5/16'' cutter. for an enclosed track use a ball cutter to cut profile (a), bill kitto sells ball cutters that are the correct size for the shaft you want to use but they are a bit pricey as an alternative you could use commercially available cutters that will be close to the shaft diameter you want to use and follow the same guide lines as an open track. the track itself could be cut directly into the wood or you could use a polymer like delrin but since this is your first gun don't make things too complicated just cut it into the wood. good luck.

steve

[qazedx]

thank yuo for attention, but to make a woden track, that sound very unreliable, I was planing to put an aliuminium rail but when I buoght it I thought it will be to soft,so I decided to put a stainlles steal barel and to make an enclosed track gun, I believe that wuold be much better, don't yuo think, what number of stainlles steal wuold yuo recomend for the barel and the spear?
and please do write me deameters in cm, I don't undestant a thing.

[marginatus]

just write in google:
9/32 inch in cm
and you'll understand

[qazedx]

nice I ddnt know google cuold do that.
so how abaut that steal

[marginatus]

It does with a lot of other units and try also
100 usd in euro for example

[qazedx]

good, so how abaut that spear and barrel metal?

[hitjohn]

Originally Posted by qazedx

good, so how abaut that spear and barrel metal?

for the spear , how long of a gun are you making and how large are the fish you are shooting? will you be using a slip tip or a flopper shaft? open water or shooting around rocks? i think this will determine shaft size and needs.

for the barrel, are you making a hybid wood / metal gun or a full length barrel out of metal? i have purchase titanium tubing 1" OD with .032 wall for not too much money. I typically use about 30 - 40 " of it though and the remainder is wood. I have not made one full length.

[qazedx]

the gun spear track (barrel) will be 1m long, I will be using a flopper shaft as it is easier to make I'll try to hunt all kinds of fish, but mostly I'll hunt in fresh waters, I believe a hard stainless steal shaf should do the job, but I'm interestin in hearin other opinions and I dont know the number of steal.
I am making a woden gun just with stell track so it wuold be longer lasting and more acurate also I believe it wuold allow me to use alot of power.
also I was wondering what size shuold be the gap in picture a)

[hitjohn]

Originally Posted by qazedx

the gun spear track (barrel) will be 1m long, I will be using a flopper shaft as it is easier to make I'll try to hunt all kinds of fish, but mostly I'll hunt in fresh waters, I believe a hard stainless steal shaf should do the job, but I'm interestin in hearin other opinions and I dont know the number of steal.
I am making a woden gun just with stell track so it wuold be longer lasting and more acurate also I believe it wuold allow me to use alot of power.
also I was wondering what size shuold be the gap in picture a)

i think with a 1 meter track you might want to consider not making an enclosed track and leave it open. the reason i think this would be ok is because the shaft is not all that long and would not require a enclosed track to aid in controlling shaft whip as it exits the gun. you can also use your choice of spear shaft tabs as well and not have to use shark fins on the shaft or pins for loading the wishbones of the bands.

another benefit is that if you are hunting around structure and happen to bend a shaft you might be able to straighten it out enough to get it to still work again as opposed to having to have a perfectly straight shaft needed for an enclosed track.

also the open track will allow for faster loading too if combined with an open muzzle.

the steel i would choose for the shaft would be spring stainless steel and if a single flopper, use one which is about 3 inches long, also determine how much shaft overhang you want coming off the fornt of the gun as well. I prefer little overhang on my own guns and i use a single flopper as well.

have you thought about what trigger mechanism you want to use yet? i think maybe in this case it would be easier to buy couple of spears with floppers pre made and a trigger mechanism for them. that way it saves you from having to machine more metal and you can concentrate on the wood working.

as for the track, do you have access to uhmw or delrin ?those would be quite slippery and easy to make as opposed to having to machine a length of steel rod for the track. if you go with the open track you can also use a JBL tru glide track which can be cut to size and epoxied onto the gun. its an easy alternative if you decide on an open track design.

[metelin]

hitjohn makes some very good points on open versus enclosed track but if you still want to do enclosed i see no reason to use metal. it would be hard to machine the top open (unless you have propper tools) and it will be noisy. an all wood track is just fine but a plastic like delrin is best but if i were i would just do it open, the gun will be much more useable with it. enclosed tracks are best for big guns with lots of power to be used in open water only because the shaft needs to exit the track completely before it stops otherwise it will damage the track. enclosed track should not be used for cave hunting for example.

steve

[qazedx]

now that is interesting, you say that there is no point in making a steal track, well as it is my first gun I'll give it a shot. hitjohn, you believe that open track will hold the spair, but if it is so when I should use the enclosed track (I mean when I'll put more power or when I'll shorten the track)?
also I have an idea to make open track more slipery,what do you think of makeing a track a shape of sqare and puting glass in the botom? it shuold be much more slipery and it shuold not affect stability dont you think?
metelin how can the shaft stop befor comes out of the track?

[marginatus]

Originally Posted by qazedx

metelin how can the shaft stop befor comes out of the track?

If it hits a rock! or a fish very close like in a hole!

[qazedx]

I see...
how abaut the glass idea?

[marginatus]

In arbalegno.com , persiko makes a track with resin and wood powder like the one you want to make (from what i understood)...
guida_asta