Posts by Guest

  • Spearguns and buoyancy

    Quote from hau

    Do you think an air filled barrel acts like a diver who is positive on the surface yet sinks past a certain depth?


    I don't think so. The only way that the buoyancy of an object changes if if the volume of that object changes.


    A diver's air filled lungs compress as he descends, occupying less volume, and providing less buoyancy.


    An air filled speargun is a rigid structure by comparison. If the barrel is 1.000" in diameter at the surface, then it should be 1.000" in diameter at normal diving depths. If the weight does not change, and the dimensions of the gun (volume) don't change, then the buoyancy of the gun should not change.

  • Enclosed track speargun

    Ok, how about this. Since there is 24" extra on the Composite Resources tube, I can cut two short test pieces (still leaving a some extra for the real tube). I will make one with the G10 track and no additional wraps. On the second, I will overlay an additional CF sleeve, and see if my cheap vacuum pump will conform the CF around the whole thing. Then we can decide which approach to pursue.

  • Enclosed track speargun

    I wasn't planning on it . With the other tube having a 0.083" wall, I didn't think that any additional CF was necessary, and would only add more weight. The G10 should epoxy very well to the CF tube without additional CF around it.

  • Enclosed track speargun

    Hmmm. That's going to be awfully thin by the time I machine the ends to a 1.05" ID to accept the RA handle and muzzle. 1.116" OD - 1.05" ID leaves only 0.066" (total), which leaves only 0.033" wall. That's just a hair over 1/32".

  • Enclosed track speargun

    Quote from hau

    Sooooo----I ordered a CF tube from him also which he is shipping to you :)
    That way you can choose which tube you think is better suited for this project.


    I was just checking out his website Hau. What size and type of tube is he sending?

  • Spearfishing dreams

    the weather in puerto rico is crappy to like a month. im so stoked with spearfishing these days and cant go to the water. i had these dream with a big grouper and tons of fish, clear waters but i think i had these dream because i spent many hours watching videos and pictures learning more. i think i was so stoked that the videos n pictures were kept in my mind. spearfishing dreams are common. hope the weather change these week.

  • Enclosed track speargun

    Quote from hau

    psychobilly---My goal with my "enclosed track barrel" thread was to gain enough information on how to build an enclosed track at home for ME to build the barrel.
    Tin Man was gracious enough to OFFER to build the barrel for me. ( he probably felt sorry for me trying to do it myself )
    Hopefully Tin Man did not feel pressured to build the barrel. That was not and is not my goal.
    I was not asking for someone to do the build.


    Nothing of the sort. It's been a cold rain here for what seems like weeks, and my mind wanders and thinks of new spearguns and you guys down there in warm(er) waters. I just thought it seemed like a cool project, so I'm happy to help in whatever way I can.

  • Enclosed track speargun

    How does the $157 price compare to others you found? If it's reasonable, then I say let's go for it.


    What size shaft do you want to use? I think I can use a piece of 1/2" G10 if you only want to go up to a 9/32" shaft. If you want a larger track for a 5/16" shaft, then I will need to start with a 5/8" thick piece of G10. The bars are only 48" long. How long will the barrel need to be?

  • Enclosed track speargun

    They say the tube has a "tape wrapped exterior finish that is easily handled and gripped." I take this to mean that it might not be perfectly smooth and shiny. That's only a cosmetic thing, but if their price was lower than others, the finish might be why.


    They say that it is "roll wrapped" construction, which I think means that it is made by wrapping a sheet of woven fabric around a mandrel. It might not be the optimal construction (compared to using unidirectional fabric), but we are compensating with a thicker wall. If the price was reasonable, then I think it will work.


    Also, their OD tolerance is listed as +/- 0.030", which means the OD could be as small as 1.130", or as large as 1.190". I wonder if it really varies that much normally? You might want to ask if that's normal.

  • Enclosed track speargun

    Hau,


    I doubt that you will find a CF tube that has both the 1.160" OD and the 1.05" ID of a RA tube. I guess the OD could possible be a little larger, as long as the handle and muzzle don't wrap around the outside.


    For the inside, if you can find something with a slightly smaller ID (like maybe 1.00") then I can machine it to the proper 1.05" ID.


    Of course, larger OD combined with smaller ID means thicker wall which would be a little heavier. And don't forget that we would also need appropriate plugs at each end.


    How much would it cost to just buy the barrel from RA? I could easily machine off the existing track, and I don't think that it would adversely affect the strength since we are bonding a larger G10 track right back in the same place.