Dirty Water Rollergun

I think I got em all back. I got all cute and was going to organize my photos in photoshop, and severed the link without realizing what i was doing. I re- downloaded from my computer hoping it would recognize and re-establish the link. Looks like it dit.

Two things:
1. Cleaning up and organizng can be bad.
2 Even a blind hog finds an acorn once in a while.

Quote from Marco

I don't know much about rollerguns, but what I've seen is that with just one band, you get enough power.
Isn't much complication to use 2 bands?

I'll like to see the gun fully rigged though.

You are probably right. Two bands are definitely more complicated than one on a rollergun, and for shooting fish at fairly short range, one is probably plenty. This gun is a learning gun for me, however, so I wanted to experiment with several options, such as hard metal wishbones, or soft, one band or two, does it matter if it's the front or rear band, effect of the compound lever on penetration, etc. I see this gun as sort of a test platform to actualy see in my little test tank whether this sort of stuff makes any difference, or is academic. I understand this is a fairly unscientific approach, but if I keep everything else the same, I can probably draw some conclusions.

When I fire a 9/32 and a 5/16 shaft, for example, I am getting almost twice the penetration into the target with the 5/16" shaft. I get the same results with one band or two, at 7' and 11' (from the muzzle). I wouldn't have predicted so much difference. I fact, before I actually shot the different size shafts I couldn't decide which I thought would have more penetrating power. The 5/16 shaft has more mass, but has to be moving slower, has more drag going through the water, as well as through the target, etc, etc. Being able to make actual test shots helps cut through all the theorietical crap that has an answer so dependent on assumptions that it really doesn't mean much.

There are probably a number of very good reasons most rollerguns have one band, including complexity. After I've played around with this gun (and a few others), I'll probably understand what really works and what doesn't. Then I think I'll be able to build a much more optimum gun for the use intended. At least, thats the idea.

Thanks, Lunker, but you're making my efforts sound way too noble- I just want to figure out what works and what doesn't, and if a few urban myths can be replaced with actual data along the way that's ok too. As long as we don't stop drinking beer and debating SOMETHING! :toast2:

Quote from Marco

I have a friend in Spain that built a very nice rollergun, and he told me that with thicker/heavier shafts is when you realize the full potential of the rollerguns. He uses a single 5/8 band streched to 3.5 x factor.

I can post some pictures here is you want.

Please do! I've only started tank testing, but the 5/16" shaft seems to get much better penetration than the 9/32". What diam. shaft does your friend shoot?

Quote from ddonnell

How does the lever work? Do you attach the bands to that so you'll have more slack to load on the topside, then turn the gun upside down and pull the lever and latch to get the remaining band strength? :confused1:

Looks amazing. I always enjoy seeing hi-tech gear.

In the uncocked position, the bands are relaxed with the lever toward the muzzle. To cock the gun, you move the lever toward the muzzle of the gun, then cock it using either one or two of the 5/8" bands (I take one off if I only want to use one). Then you just move the lever toward the handle until it locks down on the catch just forward of the handle. You then shoot it as you would a "normal" gun.

The extra stretch from the preload gives the gun a lot of power for it's length, since it's really band length and stretch that give the gun it's power. In this case the band length is an additional 50% because of the additional band under the gun. An additional advantage is that due to the preload, the shaft is accellerating all the way down the length of the gun, compared to the "normal" gun, where the band is relaxed when it is about 1/3 back from the muzzle. Makes for a very powerful gun for it's size. Once you get used to it, it cocks almost as fast as a conventional gun.

I have the bands cut so the elongation is 250% with the preload. It's a lot easier to cock using the compound leverage for the last part of the cocking, so it would work well for anyone who has had an injury, or is otherwise unable to cock a gun to the full 250% elongation.

The concept certainly isn't new. I think it was Jack Prodonovich (sp?) that built a lever rollergun in the 30's. He didn't have the materials and equipment available then that we have now, but the concept is pretty much the same on my rollergun as on his.

I need to shoot it some more in the test tank, then the next one (there ALWAYS is a next one) will be a midhandle rollergun with a remote trigger about 42" or so- maybe with a stock made from some of that sexy colored plywood. :thinking: