I've been busy w/ guns this winter. On april first I can get busy w/ diving. Here's one of the last winter projects.
LOA: 23.5" or 60cm comparible to 32.5" or 83cm euro LOA
"Euro Barrel Length": 12",30cm comparabile to 23.5",60cm euro gun
Band stretch; 24",61cm
6mm Spear Length 26", 66cm
Roller Dimensions: 1 1/4" x 1/2" rated to 300lbs set on 1/4" bolt.
one x 16", 41cm 5/8ths powerband
~8' range from handle to 2/3 shaft length.
4" pushrod
Weight ~2.2lbs Ballasted
I have no idea how this will shoot. The combination of the roller and the short pushrod allowed me to effectively cut the barrel length in half from a 60cm euro gun to 30cm rollergun barrel. So this THEORETICALLY will have more power (based on band stretch) than a 55cm gun which is the smallest common comercially available gun. This might be nice for holes and Charleston-esque visibility 0'-4'.
I have concerns that the shaft will be too light to have a strong impact at 8' the maximum range. If this proves to be the case I will have to cut a new shaft from 9/32 or 5/16 and see if that works. I also don't know if it will be accurate w/ such a short barrel. I'm looking forward to getting it wet. Of course this gun will only be used in 0-6' vis so it's speed and manuverability might do the trick.
The construction is similar to my first homebuilt w/ fiberglass over wood construction. The trigger is lexan. The line release is a home made fiberglass 'aligator' clip which is nice w/ one wrap but a real pain in the @ss w/ two which I prefer. It is now rigged w/ 2 wraps of ~250lb vectran w/ a polyester core. I might re-rig w/ one wrap and lose ~2' or 25% of my range if need be. The line must be wrapped like a Spearfishing specialites 'speedload'. In other words a small rubberband/bungie is rigged on the shooting line so both wraps can be set at the same time. The under of this gun, and the entire thing for that matter, is very cramped. It was hard to find space for all the things that need to be on the gun shooting line, lanyard hole, line release, etc. The shooting line wraps must travel back and forth w/in a 1/2" width for it entire length to avoid the bands on the underside of the gun and the rollers. B/c of this I made the muzzle closed w/ a 'u' shaped piece of stainless.
The ballast is a little light so the butt floats up w/ the shaft in but it is overall negative. The lead was added to the handle so the gun stays in a natural sshooting position when released. The rollers offer sufficient weight to keep the gun muzzle heavy.
There are groves routed into the underside of the gun on either side for the band to sit in when the gun is loaded and lower drag (Of course you could swing a mailbox underwater if it was this short). The muzzle is enclosed on either side of the rollers to keep the band in place. I build the gun w/out this but had to add it to keep the bands from, painfully, jumping off the rollers. It was tricky to load at first, but I've got a technique that works pretty well and now can pull it back no problem, not sure I could handle one twice this length though.
LOA: 23.5" or 60cm comparible to 32.5" or 83cm euro LOA
"Euro Barrel Length": 12",30cm comparabile to 23.5",60cm euro gun
Band stretch; 24",61cm
6mm Spear Length 26", 66cm
Roller Dimensions: 1 1/4" x 1/2" rated to 300lbs set on 1/4" bolt.
one x 16", 41cm 5/8ths powerband
~8' range from handle to 2/3 shaft length.
4" pushrod
Weight ~2.2lbs Ballasted
I have no idea how this will shoot. The combination of the roller and the short pushrod allowed me to effectively cut the barrel length in half from a 60cm euro gun to 30cm rollergun barrel. So this THEORETICALLY will have more power (based on band stretch) than a 55cm gun which is the smallest common comercially available gun. This might be nice for holes and Charleston-esque visibility 0'-4'.
I have concerns that the shaft will be too light to have a strong impact at 8' the maximum range. If this proves to be the case I will have to cut a new shaft from 9/32 or 5/16 and see if that works. I also don't know if it will be accurate w/ such a short barrel. I'm looking forward to getting it wet. Of course this gun will only be used in 0-6' vis so it's speed and manuverability might do the trick.
The construction is similar to my first homebuilt w/ fiberglass over wood construction. The trigger is lexan. The line release is a home made fiberglass 'aligator' clip which is nice w/ one wrap but a real pain in the @ss w/ two which I prefer. It is now rigged w/ 2 wraps of ~250lb vectran w/ a polyester core. I might re-rig w/ one wrap and lose ~2' or 25% of my range if need be. The line must be wrapped like a Spearfishing specialites 'speedload'. In other words a small rubberband/bungie is rigged on the shooting line so both wraps can be set at the same time. The under of this gun, and the entire thing for that matter, is very cramped. It was hard to find space for all the things that need to be on the gun shooting line, lanyard hole, line release, etc. The shooting line wraps must travel back and forth w/in a 1/2" width for it entire length to avoid the bands on the underside of the gun and the rollers. B/c of this I made the muzzle closed w/ a 'u' shaped piece of stainless.
The ballast is a little light so the butt floats up w/ the shaft in but it is overall negative. The lead was added to the handle so the gun stays in a natural sshooting position when released. The rollers offer sufficient weight to keep the gun muzzle heavy.
There are groves routed into the underside of the gun on either side for the band to sit in when the gun is loaded and lower drag (Of course you could swing a mailbox underwater if it was this short). The muzzle is enclosed on either side of the rollers to keep the band in place. I build the gun w/out this but had to add it to keep the bands from, painfully, jumping off the rollers. It was tricky to load at first, but I've got a technique that works pretty well and now can pull it back no problem, not sure I could handle one twice this length though.
