David Smith's hybrid speargun project

[oneoldude]

Mark,

A while back you posted David Smith's project URL. Apparently that project is a quasi-clone of a gun made for you by a master wood-worker. In that thread you said,

"If you use a line release system like the one adopted in mine make sure that the part of the pivoting release that touches against the bottom of the shaft is as wide as possible and not skinny as to be able to lift the shaft and wedge beside it. This sometime happens if my shooting line is too tight as it has a tendency to pull up the release."

My question is about the line release. Does it hurt accuracy? It seems it might lift the spear, especially if the bands are parallel to the spear. Could you discuss its pros and cons? Is the gun built for you accurate?

The reason I ask is that I am in process of making a 100 cm rear handled gun with an american trigger but otherwise a sort of an American Master America clone and would like to use a line release similar to the David Smith version. I am concerned about the release's effect on accuracy and whether I should use two parallel bands, two bands pulling down or one parallel and one down like the Master America.

Any help will be appreciated.

Thanks

oneoldude

 

[Mark Laboccetta]

Hi oneolddude,

That question used to come up quite often, especially a few years ago when we were still selling guns with alligator clips/pinch-style line releases. In my gun the line release mechanism is not a problem considering that when the bands are stretched the shaft is pulled down and seated nicely inside the groove. It's a little quirk that sometimes just makes preloading cumbersome in that the line needs to be loose before loading or the release needed to be unwedged from the shaft. Regardless, the slight pull on the line release is nulled as soon as the shaft is released the first few inches during the shot since there is no more pressure on the line release.

On the older style alligator clip/catch-style releases people always wondered what the repercussions on the flight of the shaft were, especially if someone was skilled enough to manage to put two loops of line in them. It was however never the slightest problem though if the gunwas powered correctly because the power of the shaft during the flight would always undermine any slight sudden friction from the release.

And while I commend you for undertaking this project you described below I just hope you have plenty of spare time for testing and trial and error. I'm also assuming you have probably spent considerable years in the water with a single band gun produced by a professional and reputable manufacturer so you have a good backbone of experience to start with as far as balance is concerned. An acute understanding of a properly balanced single band design is fundamental in undertaking a more complicated design like the Master America which adds more mass, maneuverability, balance, accuracy and the proper alignment considerations to the equation. The thing should be pretty close to neutral in the water with the shaft and bands and all the reast of the stuff I just mentioned should be right too. While I consider myself somewhat knowledgeable and some would even say experienced on the aforementioned subject, I would never undertake a serious project like this myself unless it was just for shits and giggles While I consider myself pretty handy I'm just a spearfisherman and a technical geek but I'm no architect or engineer. To really do one of these right the latter is a requirement I think.

While that may sound like a sales pitch for the Master America I just want to let you know that the gun you saw me describe in an earlier post was pretty but it was nowhere near being perfect. It was also taken into consideration and looked at by the guys at Omer pretty closely (I sent it to them along with a bunch of other wooden guns) until five years later they came out with one on their own correcting many of their shortcomings on CAD. Looking back at my custom teak gun design today, as pretty as the lines are, I can tell that it could stand to be a few pounds lighter and the fuselage could be redesigned to be more maneuverable and agile. The point of this design, while I might not have realized it then, is to make the diver feel like they are actually holding a much more maneuverable and lighter gun than it is while retaining the benefits of a heavier and more powerful gun such as power and recoil control. I think mine was the Model T of this design and the production Master America is actually the Ferrari Testarossa I have never used a gun with better balance before. Nowhere near it which is why I am so exited about it and I think most people who try it that know what they're doing will say the same. It's like one of those things, if you put an experienced race car driver in a fine race car he'll praise its attributes since they can keep it under control. If you put a rookie in one they'll tell you the brakes are bad and it's unstable.

Anyhow I’m probably just preaching to the quire as you have probably put your share of time in the water shooting at fish with stick and slings. And oh yeah, don’t think your email has gone unnoticed with the questions and suggestions about our website, I’ve just been bogged in a million projects and you may just see what you wish for on our website in the near future. To strait spears and curvy rears!

 

[oneoldude]

Mark,

Thank you for your considered reply. I think you have given me the information I need. To put it succinctly; at least one band must pull the spear down for the release to work properly.

By the way, no need to apologize for promoting your products. Everyone here knows what you do and we understand you must sell to live in a manner to which you would like to be accoustomed In the meantime you have been very helpful to us all. My kudos to you. And thanks for the information you pass along while making a pitch and vis versa :king

You might say I am making a gun for "shits and grins". I am doing it because I like doing it. I built my first gun from scratch (spear and trigger too) almost 50 years ago. It was an accurate little devil and it put some good eats on the table for my parents and siblings. Now that I am a lot older and a little wiser, I think it will be great fun to make a much better gun. And if I do it, why not go for a really good design?

I do not intend to copy the MA. But I do plan to use some of its concepts and marry them with some American concepts. It will be an AmEur fusion. That's right a "Fusion" gun rather than a "hybrid".

As you point out, the goal is to use static (mass controlled) and hydraulic (shape controlled) forces in such a manner as to impove the balance, handling and recoil of the gun. With a little work I believe I will do better than the factory produced guns I currently own. I hope I will stop there. Otherwise it will never end. And we all know what that is like :duh

One more thing. The ovaloid "cuttle bone design" of the MA suggests that moving it vertically will require a special technique. It looks like it needs to be rocked left and right to move the gun in a "falling leaf" motion. Could you elaborate on that? It seems the only way to me. But I have not tried it yet.

Re your site. I am sure when you post the data many will be informed and pleased. Good luck with it.

Thanks

oneoldue

 

[Mark Laboccetta]

Hey again there,

Yes exactly, you would need at least one diagonal pull band to pull the shaft down into the barrel. One is enough to achieve that and the other in line one makes the best of it's linear pull with the shaft to run the natural return of the recoil of the rubber.

I think a little history on the "Master" concept is in order to answer your question. The whole cuttlefish design was centered around the thinking that experienced spearfisherman stalking snapper and open water prey posted up behind a rock were more concerned with lateral tracking and stability for a far reaching shot than vertical maneuverability. Therefore the cuttlefish shape aids in keeping the gun stable and light on the wrist while the diver is extending the gun forward as far as possible and tracking it from side to side when you're at the right depth on the same level as the fish. So you are right, tracking laterally is the most efficient way to do it and vertical and fast pointing like one would do swimming in and out of holes requiring surprising fast sudden movements would take a back seat to it's intended aim. While it may sound like you have to readjust your aiming the maneuverability it is still light years ahead of it's heavier domestically produced counterparts. Those guns are heavier and used mostly for the intended purpose of spearing while on SCUBA where these virtues aren't as much of a priority. Have fun with your project,

Mark