DIY Aimrite Roller

  • Anyone convert an Aimrite railgun into a roller? I have a 140 Super Venom I want to cut down to a 100-110 roller gun for an all around reef to blue water travel gun. I've looked at Marou and MVD muzzles. I like Tinman's R&D with the roller, but am looking for a muzzle that is already available. Ideas?


    Mahalo,
    Makoa

    HUI KOA KAI O HAMAKUA
    MAHALO KE AKUA
    E MALAMA I KE KAI

  • Did you convert it to a roller? If so, what muzzle did you use?

    HUI KOA KAI O HAMAKUA
    MAHALO KE AKUA
    E MALAMA I KE KAI

  • So I ended up buying the MVD roller muzzle for the Super Venom barrel. The Omer MVD roller muzzle fits the Aimrite ID. I cut the 140 down to a 110. Now I just need to figure out the best band set up for this. Any thoughts? 14mm, 16mm, 18mm? 7.0, 7.5mm shaft?

  • I know there are "Speargun Tech Gurus" out there that have this all dialed in as a science that can help. For me it's an art...trial and error...simples minded island boy? Cheeho!:thumbsup2:

    HUI KOA KAI O HAMAKUA
    MAHALO KE AKUA
    E MALAMA I KE KAI

  • From what I've read, a rollergun makes a difference when shooting a heavy shaft, so I would go with 7.5 mm if buoyancy is not an issue. 16 mm bands looks like a good compromise.


    I'm not a speargun guru though.

    Marco Melis

    A bad day fishing is ALWAYS better than a good day at work.

  • I am eagerly following this post, can't wait to hear your thoughts on roller guns when you are using it.

    A bad day at sea is better than a good day in the boatyard
    George Steele

  • The trickiest part of building a pipe roller is the band anchoring points on the underside of the barrel. In the pictures I see only one, the handle trigger guard, which will only allow maximum stretch. Possibly the reel mounting base depending on how strongly it's attached. Tying the bands to the trigger guard makes for an even bigger mess when it's time to load. Not something I'd want to deal with. But it's a good way to get a feel for how the roller shoots with a minimum investment of time and effort. I already have my own unshakeable opinion of a pipe roller speargun. But I am curious to hear Makoa's after trying it.


    Not a guru by any means but I'd go with a 16mm band and 7mm shaft.

  • Yes, I'm using the forward trigger guard for now. If I like how the roller gun feels and shoots then I will explore ways to set up two anchor points for 75% and 100% power. I've used 16mm bands at 48 cm for a band stretch coefficient of 3.4 ISH. I'll try both shafts and decide.

    HUI KOA KAI O HAMAKUA
    MAHALO KE AKUA
    E MALAMA I KE KAI

  • You can use a cord attaching the band to the trigger guard, in a length that allows easier loading at %75. Then once the band is loaded on the shaft you can turn the gun over and load to the reel mounting base which will be close to %100. If you attach directly to the trigger guard it will be very hard to load straight from the max stretch point. Once you fully load the band, the length of cord will become slack and possibly get in the way.


    The only way to make a secure anchoring point is to put backing material inside the barrel and seal on each side, in addition to the plugs at each end of the barrel. This increases the weight of the carbon gun. You can only do one such anchor because after the first is done you will not have access inside the barrel to seal the 2nd anchoring point from both sides. If you don't seal you'll have water intrusion.

  • The only way to make a secure anchoring point is to put backing material inside the barrel and seal on each side, in addition to the plugs at each end of the barrel. This increases the weight of the carbon gun. You can only do one such anchor because after the first is done you will not have access inside the barrel to seal the 2nd anchoring point from both sides. If you don't seal you'll have water intrusion.


    This is the main reason I haven't been to keen to buy any of the pipegun rollers, and I don't want an ET, so the OMER ET roller is out although it has a seemingly good system. Now I wonder if maybe MVD has found a nice solution for it. I've never assembled or disassembled a pipegun before, so I don't trust my own judgement on this issue. What do you think? Will the barrel plugs in this kit be sufficient?
    I imagine you push the plugs into the pipe and use them as support for a band rest screwed on from the outside. Will the small hole you need to drill to through the tube to attach the the band rests weaken the tube sustantially?

    Edited 2 times, last by Anders: Forgot to add link ().

  • I don't think the O-rings on those plugs will stop water intrusion. For them to work the tolerance would have to be so tight that you would need a press to push the plugs down the tube.


    The band anchors need to have a design that distributes the stress over a larger area of the tube than just the screw hole. One aspect of this design would require the anchor to be very form fitting to the tube, although some loose space can be taken up with epoxy. A two screw anchor would be better.

  • Thanks Dan. That's what i was afraid of and I guess in a thoroughly sealed pipe gun you use plugs in addition to the O-rings on the handle/muzzle.
    Being round, and hopefully fairly close in diameter to the tube, the plugs with O-rings could be sufficient as band anchors, but not ideal?

  • Yes there are plugs. It's pointless to have O-rings on the handle and muzzle, they don't do anything.


    Seeing as how the O-rings are useless there's nothing special about those MVD plugs, but they should provide ample support for the anchor. I just used a Delrin "dowel" with the right diameter for the tube.

  • I used plugs (from Freedivestore.com!:thumbsup2:) in addition to the MVD muzzle O-ring. I wouldn't chance any modification on a pipe gun without plugging the tube so that water has no entry point into the open cavity of the tube. The roller I show in this post shoots amazingly...I love the accuracy and power increase of the gun, but definitely has a learning curve associated with loading, etc. I can see how a roller muzzle on a wood gun affects the handling less than on a pipe gun due to the ability to streamline rollers and bands along the longitudinal axis of the gun, as I can definitely tell that the tracking of my roller gun is a little different than before. But it accomplishes what I need...a smaller travel gun that I can use reef and bottom hunting but with capability to hit bigger fish in open blue water.


    Dan, have you heard of guys injecting high density foam into the barrels of their pipe guns? I Saw a guy do this on YouTube. I've used high density foam in one of my hard lifeguard rescue can floats to avoid the collapse of the float at deep depths and it works great. Not sure this would be a functional alternative for anchoring band tabs on the pipe? I've used the marine grade HD foam from a can.

    HUI KOA KAI O HAMAKUA
    MAHALO KE AKUA
    E MALAMA I KE KAI

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