help for a newbie picking shaft size, and bands

[joker]

Hey all, well it's time for me to start building my speargun, and I am wondering how to determine shaft size and such....

I am hunting in freshwater...visibility really depends on the lake, and I will be mostly after panfish and carp..

I don't need much power for panfish, but for carp i need alot.

I was thinking getting a 3/8"x42" shaft...

but for bands i don't know how to determine this... I know for carp i need alot of power cuz they are so tough... but how should i determine what size bands to get????
any suggestions on spear length, diameter, and band width and length??

Thanks,

joker

[beamjoel]

try 9/32 or maybe 5/16 shaft. I thing your 3/8 shaft would more than destroy a panfish. I have never hunted in fresh water before, but my bread and butter gun only uses a 5/16 shaft and it is plenty for fish in the 50lb range and much higher.

Try also checking in on the DIY or homemade forum under hunting equipment.

good luck

Joel

[spaghetti]

One 20mm circular band with a 6,5mm shaft, the length depending on gun's length of course..
Assuming that you're building a relatively short gun (barrell lenght max 80 cm or shorter, I guess), any heavier band load would screw up both accuracy and waving/aiming, and a thicker shaft would have no velocity.

[joker]

okay soo 5/16"x32" shaft.

[beamjoel]

depending on how many bands you will be using? but 3 9/16 x 18" should give you plenty of power.
with a 5/16 x 42 shaft
are you making a rear handle or mid handle?

good luck

Joel

[joker]

rear handled

[beamjoel]

should work good. good luck and like i said check out the DIY forum.

good luck

Joel

[bluegroper]

One 20mm band 1/3 of the stock length and a 7mm shaft 200mm longer than the stock. That will set you up to take on just about any fish you want.
Have fun.
Woodsy

[joker]

okay..well what if i want to put on 2 or 3 smaller bands, just to be able to take on smaller fish without destroying them...would I just divide 20mm by 3 and have 3 bands like 7mm in diameter?? Would that be okay?

[spaghetti]

Originally Posted by joker

okay..well what if i want to put on 2 or 3 smaller bands, just to be able to take on smaller fish without destroying them...would I just divide 20mm by 3 and have 3 bands like 7mm in diameter?? Would that be okay?

well, this is a big
NO!

[joker]

Okay okay, i figured it out by talkin to someone, but just as a general guide, to determine band length, halve the barrel length?? Because that is what 42 cm is...so is that a good guide???

Don't wory spaghetti, i got it figured out, thanks.