a speargun in the making.

[IvarNelson]

Hi everybody. I have started my project, which is abuilding a speargun but i have run in to some problems.
I attach these pictures so that maybe anyone can identify the trigger mechanism I have (bought in in Australia 2004). I think its a AB Miller trigger for 5/16" spears but i am not sure. the trigger mech is made out of some kind plastic or composite material.
My problem is ordering the right stuff. What spears can i use with this trigger mech? where can i buy them? is the trigger mech of good enough quality?
What spears go together with what trigger mechs? They never show the end of the spear that hooks in with the mech in the pictures in the online shops.

My gun is made of oak, i suppose its not the best material but hey, its the first gun i make so i guess it wont be perfect anyways...
It is 100cm long and about 80cm from where the trigger mech is gonna sit to the end of the gun. How long should the rubbers be and how many? I think ill buy bulk rubbers and then just try what lengths seem to fit.

I have found a site that sells AB MILLER spears for freeshafting ( http://www.spearfishinggear.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=ABSHS ) and i suppose these spears will fit my trigger mech. ( the measurements in the attached picture are taken from a spear the fit the mech, from the shop where i bought the mech). the problem with them is if I buy one of those spears how will I attach the line to my gun?

All of there problems/questions, and probably more to come, have made think that maybe i should just order a more well known mechanism, like Riffe? and then i can order spears from a shop closer to me (I live in sweden and the closest spearfishing sho is in norway). Just seems to be a lot of hassle using the AB MILLER trigger mech and im not sure if its very good quality.


Thank You for any help! I plan to put together a little guide about making a speargun when I have completed mine so please help me.

Ivar Nelson
Sweden

 

[socalspearo]

The mechanism you have is an AB Biller (not Miller). It is the same mechanism as the Australian Sea Hornet brand and the US Spearfishing Specialties brand. They all take the same spears and the site you quoted is a good source. As far as mechanism strength, I have heard of these mechs being loaded with up to 3 5/8" bands or 2 3/4" bands without problem. In other words, as long as you're not making a tuna slaying beast of a gun, you should be fine.

Many people use and love the Biller products and actually, the replacement spears are some of the least expensive on the market (shipping to sweden aside!).

Biller also sells 9/32" shafts that are compatible with that mechanism. As for attaching the shooting line, you can order a shaft with a hole already drilled (the biller freeshafts come this way if I'm not mistaken) or you can use the slide ring set-up that comes standard on most Biller guns. Check out the AB Biller website for pics and also read the thread called "Teak, laminate or not" to see some pics of a gun made by stoneshot using that mechanism.

Good luck.
Logan

 

[IvarNelson]

Thanks alot for your help socalspearo! I feel more confident that my prjoect will work now that I have seen pictures of others using the same mechanism!
Anyone with more answers regarding my other questions, like rubberband length.
If anybody have tips about how to create the spearguide?

 

[socalspearo]

I'm not sure how others make the spear guide. The best way I have found to do it is to use a router mounted under a router table. That way you can move the fence into the correct position and then simply run the entire length of the gun across the table. You could also just use a router with an edge guide but it can be tricky to balance the router on top of the thin barrell.

 

[stoneshot]

The Biller Mech. is not the same as a Austrailian Seahornet mech. The Biller has a stainless drop sear as the SH has a brass sear. The Biller mech. can hold a little more pressure than the SH.

The Sh mech is a tried and true design and has been around for a LONG time...

 

[Dan Man]

The seahornets don't have a brass sear...thats the Australian undersee mechs that look like a riffe mech!

I have a seahornet mech here right now and I have pulled it apart and its stainless not brass.

I wouldn't reccomend using any more than 1 band because the trigger pull gets very stiff. I had two 16mm rubbers on one of my eariler guns with a SH mech and the trigger pull was rather hard...it actually took enough effort to distort your aiming!

However they are pretty good for just single 16mm rubbers and single 20mm rubbers. They can take 7mm spears and 8mm spears.

You can use riffe spears in them but the thing that stops them going in is the shark fin at the back. So you either grind off the shark fin or file a little bit off the top off the mech to allow the sharkfin to fit in. I did this and had no worries. Filing off the top of the mech doesn't effect it at all because the spear engages into the mech at the very back.

You can see how I did this in this pic.

That guns was made from oak and meranti and I have since sold it to a chap in north QLD.

Also you should cut the trigger down a little so its more straight not with a big curl on the end...makes it very hard to make a trigger guard for it.

Also where you have shown the mech on the gun you should mount it a bit more forward. On that note you should also know that when the spear is engaged into the mech the trigger actually sits forward about 10mm so you should get a spear for it before mounting it into the stock.

For the line anchor on the gun you can do many things. You can cut out a bit of stainless and screw it on with a bit folded up with a hole in it, use some stainless sailing saddles, screw eyes but the cheapest and one of the strongest is just simply drilling a hole through the stock near the muzzle. I have my own design involving a D shackle and pinning it to the stock with resin but thats for another day!

I live in Australia and have used the SH mech and I am pretty familia with them so if you need any help just post it here!

 

[IvarNelson]

Thanks a bunch! all of you!
But Dan Man, why have the mechanism further forward? I understand that it has to be sligthly more forward but just a tiny bit so that the trigger doesnt hit the handle? is that what you mean? or do you mean for making a trigger guard i have to beware of the trigger moving to a more forward position when loaded, i know that and i have made a small loading device, which looks like a spear in, only shorter.

Thanks again everybody! I feel much more encouraged to continue making my gun, it seems now all i have to order is spear and rubber.

One more question though, some of you say that the mechanisms are different (Biller, undersee and spearfishing specials), but they all carry the same spear?


Ivar Nelson

 

[Dan Man]

Yeah I mean so it doesn't hit the handle. It would suck if you made it all and you couldn't pull the trigger back! Just something to be aware of. I personlly like my triggers to let go of the spear about 5-10mm from touching the handle.

Different strokes for different blokes I suppose!

 

[stoneshot]

harded steel. I have been using them for around 15 years on over 35 guns. That is the reason that are comming out with a stonger trigger. Undersee mechs. have always been superior to SH mechs. I have loaded an Undersee mech with four 9/16" rubbers and never found it any harder to pull than a Riffe fully loading with the same rubbers. I take probably over 1500 shots a year, so my triggers get a workout, SH are great consistent triggers, and should be even better once they release the new ones. But the current trigger on the market will not hold more than two 5/8" bands cut to the proper length, then they get hard to pull. Biller redesigned thier triggers originally based on the SH a few years ago using a hardened sear to hold three 5/8" bands.

 

[hcknudsen]

Hi there Ivar, I read this post with great interest since I think it could be fun to build a gun my self in the cold wintermonths, have you gotten any further with the gun?
Since I live in Norway, Oak would probably be the easiest for me to get my hands on, do you have any further feedback on your use of Oak.

Hans-Christian Knudsen

 

[poacher]

Any good timber for ship building should be OK not sure about oak but beech is good

 

[Mr. X]

... beech is good

Really? I have never seen a use for beech before. There are a lot around here. I have some limbs on my wood pile that came down in heavy winds last year -- very, very dense/heavy, I was quite surprised, it crossed my mind might not even float (TBD!).

 

[IvarNelson]

Hi again guys, im glad so many are interested in my little project. I am acctually doing for a school project now and I am going to make my own trigger mech as well. will probably keep a bit of a diary of the work being done and post some pictures at my website ( http://egy.nu/~u86nnir ). I might be in swedish though, since my teachers will want to look at it and read, but you guys can still look at the pictures at least...
Anyways, I will post some pictures tomorrow, did some work on it tonight. I am having some problems figuring out how to make the trigger mech pocket watersealed. I have sort of 'molded' a pocket for it now with a two component glassfiber filler. hopefully it will work. I will order some rubber from a firm in sweden that makes these rubbersbands training and aerobics and stuff. The big problem now is the spear, i will have to buy some kind of steel bar/rod and do some welding work on it in school.
I will try to take as many pictures as possible and post them.
Also, i have bought heaps of two component epoxy (could only get the small packs so i bought 10 of them and i think if i dissolve it a little bit with acetone I will be able to paint it on to the barrel and make it waterproof that way. Has anyone got any ideas of comments on this, i really appreciate it.


Ivar Nelson

 

[Huan]

Hi there Ivar, I read this post with great interest since I think it could be fun to build a gun my self in the cold wintermonths, have you gotten any further with the gun?
Since I live in Norway, Oak would probably be the easiest for me to get my hands on, do you have any further feedback on your use of Oak.

Hans-Christian Knudsen

Oak turns black in saltwater very quickly, once the sealant is worn.
Better to buy Teak or Iroko.

 

[IvarNelson]

I have been designing a new release mechanism and building my speargun.
Doing it as a school assignment. Please check out the webpage.
http://egy.nu/~u86nnir
It is all in swedish so far but there are some pictures and will be more soon..



Ivar Nelson

 

[hcknudsen]

as to comments on wood, heard that the easy thing to do is get hold of an old teak door, the wood will have aged and you just have to cut it.

(Ivar hope you don´t mind the crossdiscussion in your thread)

why did you choose that type of trigger?

Hans-Chr.

 

[IvarNelson]

I bought that trigger when I had only heard about spearfishing and didnt know much about it, still dont have much real experience..

By the way, I have finished the speargun, I have forgot to add pictures since im more in to my new project, another speargun but everything is homemade, including trigger.

Here are a couple of pictures of the speargun with the bougt mechanism anyways, not very pretty and the elastic is not the heaviest. My close friend Jonas is posing with the gun.

One thing I havent finished is the line release. I realize there much be a massive pull on the line attached in the spear and speargun when you shoot. How many times do you "wrap" the line from the front to the linerelease?


Ivar Nelson

 

[Groupermadness]

aprox 5 times the length of the gun is a safe bet, my small cave guns are just 2 times the gun length(sliding line holder). but the larger ones are all 4 times +1 length from trigger to muzzle, but if you fit a reel you can have 40+meters so no real law on this one.
ps nice gun,

 

[hcknudsen]

congratulations on a job well done, the speargun looks nice

you can always put a shockabsorber on the line if you are afraid of line snapping when fired, these are often rubber, scubastore.com has some under guns - accessories.

good hunting with the gun, don´t forget to post further feedback.

Hans-Chr.

 

[Mr. X]

How many times do you "wrap" the line from the front to the linerelease?

Just once. (Some do twice but much less common).