Hi Y'all'
I finally got around to almost finishing my first attempt at a rollergun. I'm considering it a prototype, which is code for "I screwed up a lot of things but finished it anyway" Actually, there are some things that are new that I want to try, and depending on how they turn out, I'll build a "new and improved" version down the road a little.
I found the rollergun a bit of a challenge, trying and discarding ideas as I went. The final result looks a little like it was designed by a committee, but turned out fairly well, despite all the modifications I made as I went along. Not a lot out there on rollerguns. Phil H was helpful in his posts, and there were a few other rollergun builds, but not much.
Anyway, here goes:
The gun is only 30" overall, sinks with the shaft in and floats horizontally without the shaft. I built it for hunting the turbid water in Pensacola Bay, FL, where tin Man and I do most of our local hunting these days. It shoota a 9/32 or 5/16 shaft in an open track, and is designed to shoot either one or two 5/8" bands. We often get shots at decent red snapper and grouper, and I wanted th have enough power to shoot a 15- 20 Lb fish. Most shots are less than 12 feet, but if the gun shoots straight enough I might try rigging it for 14' or so.
I started out thinking I would build the muzzle out of aluminum channel, but as I got into it I couldn't get the strength between the aluminum and the wood I felt comfortable with, so I mortised in a piece of teak, and the muzzle became teak along with the rest of the gun. I stole the shooting line retainer idea from Bretto's post (I told you I would, Brett!). It's fastened with the forward roller axle and the pin you see between the two axles.
I installed 2 epoxy coated magnets under a delrin muzzle piece to hold the shaft in place.
The delrin rollers are 1-1/4" for the front, and 1-1/8" for the rear, and are tapered to make the rear bands move inboard when stretched, and the front bands move outboard. The axles are 3/8" aluminum bar stock with the ends drilled and tapped to hold 8- 32 screws with washers.
I'll continue in the next post.