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PostPosted: 09 Nov 2012, 10:21 
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The previous thread on this topic lost graphics - so I decided to re-do it.


Building the Southern Speargun

Introduction
I wanted to design a gun that could be built by just about anybody, and that would be useful around Victoria. The components would be available at local hardware stores, and when they didn’t carry what is needed, they should be obtainable from other places easy to get to, or which deal in mail order web-based shopping.

I like to give spearguns names. The name gives me a focus for the design, and helps me keep in mind what I am trying to achieve. I decided to call this gun the Southern Speargun.

Specifications

Design
The Southern Speargun is a modified Euro (“pipe”) gun.

Spear
I used a 7 mm diameter stainless steel spear, with a mono head (I opted for Torelli brand and purchased it at Legendary).

Stock
The stock was laminated from three pieces: a rectangular strip down the centre, and side pieces with “D” shaped cross sections.

Spear guides
Five spear guides were inset into the top of the stock. These hold the spear straight before and during firing, reducing spear whip and enhancing accuracy.

Muzzle
The Southern Speargun features a “Brett’s” muzzle, with dropped rubbers and a spear front guide made from a stainless steel eye bolt.

Spear release
I used a Picasso “shot engine”, purchased from Legendary. This mechanism takes the Euro style of spear. The dimensions of this plastic housed mechanism are not ideal for dropping into a wooden frame, but with appropriate design modifications, the shot engine can be successfully used.


Attachments:
ssg entire diagram.jpg
ssg entire diagram.jpg [ 13.81 KiB | Viewed 6871 times ]
Right hand side.JPG
Right hand side.JPG [ 58.9 KiB | Viewed 6871 times ]
Left hand side.JPG
Left hand side.JPG [ 46.82 KiB | Viewed 6871 times ]

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Ric Fallu started spearfishing in Pt Phillip in the early 1960s, and never really stopped
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PostPosted: 09 Nov 2012, 10:24 
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The Southern Speargun
Tools and materials

I wanted to use the simplest of tools and easiest to obtain materials

Tools
The design required the minimum of tools, but those tools were essential.
clamps
Wood, when being glued, needed to be held in place. The closer the pieces: the narrower the glue line, and the neater the joint. I used purpose –made clamps purchased from Bunnings as they are convenient. But its possible to use weights (as from dive belts, or even bricks). Its also possible to use a Spanish windlass – where several turns of rope are loosely taken around the parts, and then a stick is placed in the loops and twisted till it all pulls up tight.
drill
A battery drill is convenient, but at a pinch, a hand drill could have been used. 3.5 mm. and 5 mm twist bits were needed as was a 16 mm spade bit.
form
When gluing, the laminates would have been straighter if they were clamped to a form that was dead-straight. I used a metal fence post, but at times I have used the side of my ute.
glue spreader
I used an icy-pole stick, or a sugar stirrer for take-away coffee.
rasp
I purchased a wood rasp from the local two dollar store, It was cheap but worked well.
ruler
I used a tape measure, but any ruler would have done.
sand paper
80 grit sandpaper was useful for rough shaping, and 120 grit for smoothing and finishing. Sandpaper is easier to use with a sanding block.
saws
You don’t need a fancy saw, or a power saw. I used a hobby saw I purchased at Mitre 10. A coping saw made cutting the bent bits easier.

Components
Some of the components had to come from specialist suppliers, and some from the local hardware.
adhesive
I purchased a 125 gram bottle of polyurethane glue.
cordage
I purchased five metres of 2.5 millimetre spectra cord.

I got mine from the local yatching/sailing shop, but I imagine that something similar could be easily obtained from a spearfishing supply shop.

At a pinch, 2.5, or 3 millimetre Venetian blind cord could have been used.
rubber
I used 16 millimetre diameter rubber. I wanted a 3.5 stretch for the 1 metre stock, so I purchased 57 centimetres.

I got the rubber from Legendary Spearfishing Supplies, but other spearfishing supplies should be able to provide.
spear
I purchased a 7 millimetre diameter stainless steel spear. The spear was 1.3 metres in length, but anything within 10 centimetres of this would have been OK. I got a spear with rounded bridle slots, so as to reduce wear on the soft bridles.

I made the purchase at Legendary Spearfishing Supplies, but other spearfishing supplies should be fine.
spear release mechanism
I purchased Picasso shot engine.

I got the mechanism from Legendary Spearfishing Supplies.
stainless fastenings
I purchased:
• two 10 x 3/4 countersunk (CS) HD self tappers
• four 6 x 1, countersunk (CS), HD self tappers
• one eyebolt, nut and washer, 6 x 40 millimetres

I got these in Bunnings, but had to purchase packages containing more screws than I needed.
timber
I went to the “interior timber” section of the nearest Bunnings. There was an area devoted to mouldings. I went to the part selling “hardwood” which was comprised almost completely of “Tasmanian Oak”

I purchased:
• a piece of “square edge 40 x 8 millimetres” 1.8 metres in length
• a piece of “round edge 30 x 8 millimetres” 2.4 metres in length
• a piece of “30 x 18 millimetres” 2.4 metres in length

I sorted through the racks and only purchased pieces that were dead straight, and were clear of knots or splits. There is no actual “Tasmanian Oak” tree. The timber can come from a variety of species, and consequently can vary in colour and grain pattern. The thicker rectangular piece was pinkish and had little discernable grain in it. The thinner piece had a lovely, if subtle, brindle appearance. The “D”-shaped piece had another visual texture again. It seems to me that this variation enhanced the aesthetics.

These bits of timber were all longer than I needed, but were the next closest thing I could find on the rack.
varnish
I used “Estapol” two pot floor varnish, and I had some waiting in the cupboard. This, or any other varnish would have done fine.


Attachments:
tools.JPG
tools.JPG [ 84.45 KiB | Viewed 6870 times ]
ss screws and eyebolt.JPG
ss screws and eyebolt.JPG [ 169.52 KiB | Viewed 6870 times ]
shot engine.JPG
shot engine.JPG [ 77.76 KiB | Viewed 6870 times ]

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Ric Fallu started spearfishing in Pt Phillip in the early 1960s, and never really stopped
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PostPosted: 09 Nov 2012, 10:32 
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The Southern Speargun
The stock

The stock supports the spear, which sits on guides inset into the top of the stock.

At the front of the stock is the muzzle, which has a metal front spear guide and a cross-wise hole to take the rubber. At its rear, the stock is abutted by the spear release mechanism and jointed to the handle.

Construction
The stock was laminated from three strips of moulding: the centre laminate was oblong cross-section 30 x 18 mm DAR (dressed all round) mouldings, and 30 x 8mm “D” shaped strips were down either side. When the pieces were laminated together, the cross section was a square with rounded corners.

Cutting to length
First, I cut the centre laminate. I docked-off the 30 x 18mm to 1.1 metre. Then I decided which side was to be the top, and which end was be the muzzle (and marked them with a pencil).

Spear guide slots
The finished gun had spear guides on the top of the stock. The spear guides were small shaped pieces of wood that were glued into recesses on the top of the stock. I needed to cut the recesses in the top of the centre laminate, and I did this prior to laminating the stock pieces together. (At this time, as well as cutting the recesses, I also cut a slot for the eye bolt “Bretts muzzle” – but more about this later.)

The recesses were flat bottomed, each 4 mm deep and 30 mm long. I marked the sides and bottoms of the recess onto the stock with a pencil. The centre of the front recess was 120mm from the front tip. The centre of the rear recess was 120mm from the rear end of the stock. The other recesses were spaced equally between.

Using the pencilled lines as a guide, I cut down the sides of the recesses with a saw (being careful to cut on the inside of the line). Then I removed the wood between the cuts with a rasp, taking care to keep surfaces as flat and square as possible. Rather than use the rasp, I could have chopped out the wood with a chisel, or even a router.

Laminating the stock
I cut two lengths of the “D”-shaped round edge 30 x 8 millimetres strips. They were 50 millimetres shorter than the stock centre-piece, that is, they were 1.050 metre.

On the rectangular centre laminate, I marked lines 50 mm from the rear end. These lines indicated where the “D”-shaped strips would cease to cover the middle laminate. (The tongue that would be left protruding would be jointed into the handle.)

Rather than gluing all three of the stock components in one go, I glued on each side separately. This takes longer than doing them both at once, but usually results in a more accurate outcome.

I laid the rectangular centre laminate on the flat form (which had plastic supermarket bags covering it to protect it from glue). I covered one side of the laminate with polyurethane glue (except for the rear 50 mm) and then smoothed it out the glue using an icy-pole stick.

I laid one of the “D”-shaped strips on top of the glue, clamping the “D”-shaped strip to the rectangular centre piece. I took care that the edges of the two strips match and are flush.

When the glue had set hard, I unclamped the wood, I turned it over and glued on the second “D”-shaped piece.

Then I cleaned off the glue dribbles.

Fitting spear-guides
On the finished gun, the spear guides were glued into the recesses on the top of the stock. Their upper parts sat proud if the top of the stock. The spear sat in a groove along the top of the guides.

Fitting
I cut blocks of wood to fit in the recessed on the top of the stock. These were the spear guides.

The idea was to have a groove along the top of the supports. The groove is cut to lift the spear a little above the level of the stock. The top of the walls of the grooves are about 3 mm higher than the bottom, to give some side-ways support for the spear, but not to be so high they will foul on the rubber bridles.

I used the saw and the round file to cut grooves in the top of the blocks. When I first cut the guide blocks, I didn’t cut the grooves all the way down, in case I accidentally over-did it, but left the final fitting till after the gun was assembled.

I did try lying the spear in the grooves, and got the height roughly right.

Then I smeared glue around the inside walls of the recesses on the stock and slipped-in the spear support blocks. I clamped them in hard.

Cleaning up
Once the glue has set, there were messy bits over the sides of the stock and in the spear guide slots. I cleaned this away as best I could, using sandpaper, or a chisel. (A screw driver would have done at a pinch.)

(Two of the pictures tried to upload were not accepted. I will try to modify them and add them later)


Attachments:
2. Mmuzzle end of stock.JPG
2. Mmuzzle end of stock.JPG [ 58.72 KiB | Viewed 6869 times ]
4. Fabricating spear guide inserts.JPG
4. Fabricating spear guide inserts.JPG [ 81.08 KiB | Viewed 6869 times ]
5. Spear guide insert ready for gluing.JPG
5. Spear guide insert ready for gluing.JPG [ 86.15 KiB | Viewed 6869 times ]
6. Spear guide glued in place and varnished.JPG
6. Spear guide glued in place and varnished.JPG [ 55.22 KiB | Viewed 6869 times ]

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Ric Fallu started spearfishing in Pt Phillip in the early 1960s, and never really stopped
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PostPosted: 09 Nov 2012, 10:35 
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The Southern Speargun
The muzzle

The muzzle is at the very front of the stock. On the Southern speargun, the muzzle is closed, that is, there is a solid guide surrounding the spear. The rubbers are dropped, that is, they go through a hole in the stock (rather than being lifted parallel to the spear).

Decorating the muzzle end of the stock
Before constructing the muzzle, I decided to tart-up the front of the stock a little. This was not an essential part of the construction, and only an add-on for looks.

I noticed the particular piece of wood I was using for the handle looked good. The grain had an attractive pattern. I decided the final gun would look better if the handle was aesthetically balanced by a similar grain pattern on the muzzle. So I removed the front hundred millimetres of the “D” cross-section pieces on the sides, and replaced them with the some of the attractively grained wood, the edges of which I rounded to match the previous lines of the muzzle.

“Brett’s” front spear guide
The closed part of the muzzle: that is, the front guide for the spear, was what I call a “Brett’s muzzle”. (This is because Brett Illingworth showed it to me). The “Brett’s” muzzle utilises the eye of a stainless steel eye bolt as the front spear guide, and its held in place by the shank of the bolt extending down through the stock.

To make the hole to take the shank, I measured 50 mm back from the front of the stock. In the middle of the centre laminate, I drilled a 5 mm hole down through. This snugly fitted the shank of the eye bolt.

Without further attention, the eye would have sat too high. To drop the eye, I cut a slot at right angles across the top of the centre laminate. (I did this before I glued on the “D” cross sectioned side pieces.) The slot was 5 mm wide, and 5 mm deep. On the centre laminate, I marked the sides, and cut down with the saw, taking care for the cuts to be on the inside of the marks. I turned my rasp on the side, and used the thin edge to remove wood between the cuts

I dry-fitted the eye bolt into the slot and hole. I put a spear into the stock. The idea was to position the eye so that when the gun was loaded, the spear sat right at the centre of the eye.

Once the fit was right, there was a length of threaded bolt protruding below the bottom of the stock. I slipped on a stainless washer and then screwed on a nut. I measure how much threaded bolt protruded and then disassembled the eye bolt and cut off the excess thread using a hack saw and holding the bolt in a vice. (I think Brett normally doesn’t use a nut, but just embeds the bolt in epoxy).

Drilling the rubber hole
The Southern Speargun features a “dropped” rubber. That is, the front of the rubber is held in place through a hole in the stock. I set about drilling the rubber hole after I had glued the side pieces onto the centre laminate.

On one side, I measured 20 mm back from the front of the muzzle. Half way between the top and the bottom, I mark a point which was to be the centre of the rubber hole. I did the same on the other side.

Using a small drill (2mm or thereabouts) I drilled a pilot hole. First, I drilled in about half way from one side, and then I drilled in from the other side. The holes met in the middle and were right angles to the side of the stock. I took a 16 mm spade drill, placed its point in the pilot hole, and drilled halfway. I turned over the stock, and drilled in from the other side. I was gentle and took care to get a smooth and neat hole.

The hole holds the rubber, and its rear edges need to be rounded to reduce chafing. I used the round rasp to take the corner of the rear end of the hole, and then smoothed it with 80 grit sandpaper, rolled-up to make a tube.

Rounding the front
The front of the muzzle looks better if the square edges are taken off. I took the rasp, and rounded the edges on the front. Then I used 80 grit sandpaper to smooth it down.

I also filed a groove down the very front of the muzzle. I could put the shooting line in this groove and keep it neat.
Shooting line hole
The shooting line was tied to the gun by a hole through the stock just behind the muzzle.

I measured back approximately 100 millimetres from the front tip of the muzzle, and then pencilled a mark in the middle of the stock. I used a square to find the same place on the opposite side. Then I drilled a 4 millimetre hole half way through the stock. I turned over the stock and drilled in from the other side, joining-up the holes. Using a larger drill, and pushing very softly indeed, I countersunk the edges of the hole. I used the 80 grit sandpaper to smooth it.


Attachments:
dry fit muzzle.JPG
dry fit muzzle.JPG [ 66.46 KiB | Viewed 6869 times ]
Bretts muzzle.JPG
Bretts muzzle.JPG [ 69.05 KiB | Viewed 6869 times ]

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Ric Fallu started spearfishing in Pt Phillip in the early 1960s, and never really stopped
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PostPosted: 09 Nov 2012, 10:41 
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The Southern Speargun
Handle and butt

The rear end of the gun is the butt. Just in front of the butt, is the handle. The handle contains the spear release mechanism (Picasso shot engine). The handle is jointed securely to the rear end of the stock.

The handle and butt consist of several pieces of wood, fitting together like pieces of a puzzle. To make the arrangement easier to explain, it helps to divide them into the middle pieces and the side plates.

Middle pieces
The middle pieces are in the centre, between the outer side plates. They sit to the rear of, and follow-on from, the middle laminate of the stock.

Shot engine
When the completed gun was loaded, the spear was held in place by the shot engine (till the trigger was pulled). The shot engine sat directly behind the middle piece of the stock. It wasn’t glued to any of the wooden pieces, but sat in a pocket surrounded by the side pieces and with the handle proper at the rear. It was held in the pocket by stainless steel screws, screwed in through the side pieces and into holes in the body of the shot engine.

The stock had been previously glued. The “D”-shaped cross section side pieces did not extend all the way to its rear end, leaving a middle tongue of wood protruding. The tongue was 50 mm long, and was just marginally wider than the shot engine.

The front of the shot engine abutted onto the rear of the tongue. The shot engine has three short lugs protruding from the lower part of the front. I had to cut wood away from the bottom of the rear face of the tongue to make room for the lugs. Using a saw, I cut out a rectangle; 4 millimetres from the back face of the tenon and 25 millimetres up from the bottom. This left a lip on the top of the rear face of the tongue, which was 5 millimetres thick. The lugs fit into the recess below the lip.

To check that the dimensions were correct, I dry-fitted the shot engine by placing its front next to the rear of the stock. The lugs fitted up under the lip, and the edge of the taper on the front of the mechanism was flush with the top of the tenon.

Trigger-guard middle-piece
I had to fit together the various pieces of wood that make the handle and trigger guard.

The pocket for the shot engine is hollow (until the shot engine is placed in it of course). This has the potential to weaken the handle. The side plates outside the pocket boost the strength, as does the trigger guard below the shot engine.

The wooden trigger guard sits below the line of the bottom of the stock. To make it, I had to glue a strip of wood under the tongue. This piece was made from a 200 mm long strip taken from the same piece of lumber used for the stock centre laminate.

The top of the trigger guard piece supported the bottom of the front of the shot engine, that is, it had to sit higher than the line of the bottom of the stock. To make it fit, I cut away a rectangular section 50 millimetres long (to come to the rear end of the “D”-shaped outer laminates) and 12 millimetres deep.

After cutting, I dry-fitted the trigger guard piece under the tongue to see how it fit. The front of the piece came flush with the rear of the “D”-shaped side laminates.

I glued the trigger-guard middle-piece to the bottom of the tongue, taking care that the sides of the tongue were flush and parallel with the trigger guard piece,.

When the glue had cured, I removed drips and smoothed it all.

I tried dry-fitting the shot engine. There was room for the lugs, and the bottom of the engine did not foul on the top of the trigger-guard middle-piece. However, the actual trigger did foul on the middle-piece and I needed to cut a trigger and finger hole. To work out where the hole should be, I took a pencil and drew around the position of the trigger. I did this when the trigger was at rest, and when it was pulled back fully. Using these as a guide, I sketched on the proportions of the trigger hole

Looking at what I sketched, it seemed to me that once I had cut out the trigger hole, the remaining wood would be a little thin along the bottom, and really needed to be bulked-up. I sawed a thin strip from the square edge 40 x 18 millimetres and glued it along the bottom of the trigger guard piece.

When the glue had cured, I removed unwanted wood with a saw, then flattened it with sand paper.

Following the lines I had drawn, I used a coping saw to remove unwanted wood and create the empty space which would fit the trigger and my trigger finger. I made the cuts a little short of what might be ideal, working on the basis that if I made a mistake, it was easy to rasp or cut away more later.

The rear of the trigger guard middle piece was trimmed to make another tongue, which would later be fitted into the handle middle piece.

Handle middle piece
I needed to joint the tongue at the rear of the trigger guard piece to the middle piece for the handle (the rear of which would also be at the butt).

The handle piece needed to be wider than any of the wood I had purchased. I took two 150 mm long pieces of 30 mm x 18mm strips and glued them together along their narrow edges. After gluing, I had a piece 150 mm x 60 mm x 18 mm. This piece was to be shaped into the handle middle plate.

Wood is stronger along the grain than it is across the grain. To maximise strength, I ran the grain along the long axis of the handle, angled back to match the line of the handle.

There was a tongue extending from the rear of the trigger guard piece. I sawed an angled slot into the handle to joint it to this tongue. I glued the tongue into the slot in the handle. To keep it all true and flat, I clamped on a flat piece (this was not glued, and was removed later). Once the glue was dry, I removed the clamps and cleaned up the joint.

I laid the shot engine on middle pieces and drew a pencil line around it. I cut out the rear profile of the shot engine hole with a coping saw. Sawing was a little tricky as the trigger guard is thin, and could break if too much force is applied. But a bit of care and careful clamping in the vice got the job done without disaster.

The centre pieces were now together.

Side plates and shot engine
In the completed gun, there were side plates on either side of the shot engine.

Side plates
The middle pieces are narrow (18 mm). To bulk out the handle, and provide strength along the sides of the shot engine pocket, I added plates of 8 mm x 42 mm DAR (dressed all round) mouldings.

I glued on the side plates, one side of the gun at a time. Doing it this way allowed me to fit the shot engine locating screws with greater accuracy. The distance of from the top of the handle/butt to the bottom of the handle is greater than 42 mm, so a series of plates are laid and glued on to the middle plates. I found it easier to glue-on one plate, let the glue set, clean it up and then glue on another – and so on, rather than try to do it all at one time. It was slower that way, but the final result was neater.

The first side plate I glued was the top one. In the completed gun, the mechanism sits above the top of the handle, 5 millimetres higher than level of the stock, so the side plate has to be lifted appropriately, and the parts forward of the shot engine later trimmed down to the level of the stock.

Once s side plate was glued on, the handle was much stronger. I took the opportunity to cut out the shape of the handle and clean up the profile a little. I also cut the back of the handle and butt (don’t make the wood behind the shot engine too thin as this is a weak part of the design). The diagram included with the pictures gives an idea of how this was done. At the front of the trigger guard, I cut it so that there would be a continuous line once the shooting line clip was installed.

It was starting to look like a speargun handle!

Fitting mech and screws
I dry-fitted the shot engine, and used it as a template to drill 3.5 mm holes for the securing screws.

I glued-on the other side plate, let the glue set, re-inserted the mech, and drilled through from side that already had holes. I did this gently to minimise any removal of plastic in the mech.

In the completed gun, after varnishing, I used stainless steel screws to hold the shot engine in place. The outsides of the threads were slightly larger than the 3.5 mm holes in the handle and the holes in the plastic body of the shot engine.

I cut out the upper parts of the trigger finger hole using the coping saw. As this was the initial rough cut, which would most likely need to be fine tuned later, I left a little spare wood for later removal.

Building-up the handle
I glued the series of 8 mm x 42 strips down each side of the handle middle plate. These were done one at a time, waiting for the glue to set, cleaning out the waste, then gluing on he the next plate. There were overhanging bits of side plate sticking out. I cut the waste off with a coping saw, and neatened it with the wood rasp.

Then I did the other side. I also did a bit of preliminary cleaning up inside the trigger hole.

Shaping
The first lot of shaping was in the square, but I then rounded the edges with the rasp and improved the finish with 80 grit sand paper. The grain came up a treat, with a brindle look (like a brown camo suit).

It occurred to me that the rough texture left by the rasp could have been an anti-slip surface on the handle, but the brindle grain looked so good I thought I would do it smooth and shiny.

The tricky bits were on the edges of the trigger guard. Persistence brought success.

When the handle sat in my hand, it was a little longer than needed, so I trimmed about ten millimetres from the bottom. I also let my hand tell me if there were any parts of the handle that were uncomfortable. I rasped these pieces away.


(one picture was too big to upload - with luck I will edit it in later)


Attachments:
01. handle diagram.jpg
01. handle diagram.jpg [ 41.89 KiB | Viewed 6866 times ]
03. side view of tongue on stock.JPG
03. side view of tongue on stock.JPG [ 62.75 KiB | Viewed 6866 times ]
04. front face shot engine with lugs.JPG
04. front face shot engine with lugs.JPG [ 94.3 KiB | Viewed 6866 times ]
05. calculating lip depth.JPG
05. calculating lip depth.JPG [ 61.39 KiB | Viewed 6866 times ]
06. checking cut away.JPG
06. checking cut away.JPG [ 68.14 KiB | Viewed 6866 times ]
07. trigger guard under-piece glued on.JPG
07. trigger guard under-piece glued on.JPG [ 82.42 KiB | Viewed 6866 times ]
08. cutting mech recess.JPG
08. cutting mech recess.JPG [ 79.7 KiB | Viewed 6866 times ]
09.trig guard end trimmed down to tenon.JPG
09.trig guard end trimmed down to tenon.JPG [ 68.26 KiB | Viewed 6866 times ]
10. glueing handle piece to trigger guard tongue.JPG
10. glueing handle piece to trigger guard tongue.JPG [ 71.27 KiB | Viewed 6866 times ]
11. cut-out handle piece with side plate.JPG
11. cut-out handle piece with side plate.JPG [ 104.63 KiB | Viewed 6866 times ]
12. drilling mech holes.JPG
12. drilling mech holes.JPG [ 90.47 KiB | Viewed 6866 times ]
13. building up handle.JPG
13. building up handle.JPG [ 103.13 KiB | Viewed 6866 times ]
14. building up handle 1.JPG
14. building up handle 1.JPG [ 112.84 KiB | Viewed 6866 times ]
15. handle in the square.JPG
15. handle in the square.JPG [ 107.57 KiB | Viewed 6866 times ]

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Ric Fallu started spearfishing in Pt Phillip in the early 1960s, and never really stopped
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PostPosted: 09 Nov 2012, 10:44 
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The Southern Speargun
Line clip

The completed Southern Speargun held one clip of shooting line. This line was to be retained, at the handle end, by a wooden clip. The clip relies on the natural spring in timber to hold during swimming, but to release when the line is pulled-on.

The clip is located under the stock, with its rear abutted to the front of the handle.

I took a piece of eight millimetre Tasmanian Oak, and cut it 90 millimetres x 12 millimetres. Using a rasp, I removed a wide “U” shaped piece, four millimetres deep and 40 millimetres long. This started about 15 millimetres from the front end of the piece, and ended about 35 millimetres from the rear end.

In the rear end of the clip, I drilled two countersunk holes, wide enough to take stainless steel screws. I clamped the clip where I wanted it to be finally located, and drilled down through these holes, into the stock, with a 2 millimetre drill. This created pilot holes for the screw threads.

I screwed the clip on to the stock.

Using the rasp (followed by 80 grit sand paper), I shaped the front of the underside of the handle so that the lines of it aesthetically flowed into the lines of the clip.


Attachments:
1. handle and line clip.JPG
1. handle and line clip.JPG [ 74.23 KiB | Viewed 6864 times ]
2. line clip.JPG
2. line clip.JPG [ 47.47 KiB | Viewed 6864 times ]
3. rough shaping line clip.JPG
3. rough shaping line clip.JPG [ 152.27 KiB | Viewed 6864 times ]
4. fitting line clip.JPG
4. fitting line clip.JPG [ 41.74 KiB | Viewed 6864 times ]
5. shaping clip surrounds.JPG
5. shaping clip surrounds.JPG [ 43.64 KiB | Viewed 6864 times ]

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Ric Fallu started spearfishing in Pt Phillip in the early 1960s, and never really stopped
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PostPosted: 09 Nov 2012, 10:45 
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Location: Melbourne/Sth Gippsland
The Southern Speargun
Finishing
Levelling the spear
The first job was to check if the spear supports held the spear level. I dry assembled the gun and slid the spear in. Then I stood back and looked a the way the spear lay. I wanted it to be dead flat, and coming through the centre of the eye.

To get it right, I had to take a file and deepen the channels in some of the spear supports. (If too much had been removed, I could have filled the channels a little with epoxy glue, and then re-shaped them. but fortunately this was not needed).
Stripping
Before finishing, I removed the eye bolt from the Brett’s muzzle and the shot engine. I unscrewed the line clip and finished it separately. This allowed me to get to all the surfaces.
Rough finishing
I went over the gun removed any glue dribbles and rough areas with a rasp. The I followed up by sanding it with 80 grit sand paper. For the flat areas I used a sanding block to support the paper, and for inside the rubber hole and the trigger hole, I rolled up the paper.
Sanding
After finalising shaping with the 80 grit sandpaper, I used a finer 120 grit sandpaper to obtain a smoother surface. I could have gone finer still, but this was a speargun that was going to get some rough treatment in the water and on the beach, and not a piece of fine furniture to be locked away in a room, so I left it at that
Varnishing
I used “Estapol” a two pot polyurethane floor varnish. Its tough and resistant.

I made sure that I got the brush into the shot engine pocket and trigger hole. I also made sure I dribbled varnish down through the holes, sealing their internal surfaces (wiping off the excess with a brush after it had dribbled through).

I applied four coats. Between coats I took the surface down with 120 grit sandpaper

When it was all done, I left it for a couple days to allow the varnish to harden, and then I reassembled the muzzle, the shot engine and the line clip.

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Ric Fallu started spearfishing in Pt Phillip in the early 1960s, and never really stopped


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PostPosted: 09 Nov 2012, 10:46 
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Location: Melbourne/Sth Gippsland
The Southern Speargun
Rigging

There is not much rigging on the Southern Speargun: basically just the rubber and the shooting line.

Rubber
The gun features a single 16 mm rubber, with a 3.5 to 1 stretch. The rubber goes through the hole in the muzzle. The “Brett’s muzzle” with the eye bolt, reinforces the stock, limiting any possibility of the rubber splitting it.

I needed 57 centimetres. After cutting the rubber, I tapered the ends. This is for aesthetic purposes only and doesn’t have any impact on function of the gun. I made the tapers by inserting a nail up the hole in the middle of the rubber, using this as a handle, and abrading away unwanted rubber on a power grinder. A simpler, but not quite so pretty, way of doing it is to clip off the corners with scissors.

The rubber had a soft bridle, that is, the place where it attaches to the spear is spectra cord. The cord has balls on the ends, and these are lubricated with silicone grease and slipped into the hole up the centre of the rubber. They are held in place by 3 mm Venetian blind cord, lashed into a strangle knot. Details on how to do this are in lots of places on the various forums and advice can be got from most spearfishers, and shops selling spearfishing gear.

Shooting line
The shooting line connects the spear to the gun.

I used 2.5 mm spectra braid but the line can be anything from 3 mm Venetian blind cord to monofilament. I measured the length by placing the spear in the gun, tying the line into the hole for it just behind the muzzle, then running the line back, putting it into the line clip, running it forward, up the slot at the very front of the muzzle, through the front spear guide (the “eye” of the eye bolt) and down along the spear to where the hole is in the rear of the spear.

I only had one clip of line, as there is no real advantage in having a longer shooting line, which would be inclined to tangle anyway.

I used bowlines to tie in the shooting line, but most other knots will work OK, as long as they are not too bulky.

Having a closed muzzle means that the cord can be a little loose and not impact on the functioning if the gun.

In the gun I built, I also included a bungie in the line. It wasn’t really needed but sometimes a bungie will stop a fish from tearing off the spear.

Line clip and or lanyard
When I berley, I like to clip the gun to the float. I bent up a staple (a “U” piece) from 3.5mm stainless steel rod. Using a file, I roughened the tips a little (to assist glue to grip it later).

I drilled holes in the bottom of the handle that were the same distance apart as the ends of the staple. I dribbled a little epoxy glue into the holes and knocked the staple into the handle.

This staple was more than adequate to hold the gun to the float, but if it had have been subject to a lot of force, it might pull out.

If I had have been keen, I could have screwed on a stainless fitting and tied-in a lanyard. The lanyard can be attached to the float line to form a tethering rig, sometimes useful to fight a big fish. But since I planned to use the Southern Speargun mainly in Port Phillip, the chances of needing such a rig were too small for me to bother.

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Ric Fallu started spearfishing in Pt Phillip in the early 1960s, and never really stopped


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PostPosted: 09 Nov 2012, 10:48 
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The Southern Speargun

Using the gun
It’s all very well building a gun, but using it is what counts. I tried the gun out near Black Rock in Port Phillip.

Loading the gun was easy.

With the robust stainless steel eye bolt at the muzzle, it was a little front-heavy, but since this is not all that big a gun, it was still easy to handle and manoeuvre.

The spear support arrangements were a little fiddly, and you had to be careful about the way you arranged the shooting line. With the wisdom of hindsight, I speculate that really only two spear supports, one in the middle, and one under the front loading notch on the spear, may have been enough.

First blood was a flathead. After that, I did little target shooting on just legal size whiting, which present a narrow target. The gun was quite accurate and neatly took the whiting.

So, it was easy enough to use, and killed fish.


Attachments:
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First blood.JPG
First blood.JPG [ 61.68 KiB | Viewed 6862 times ]

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Ric Fallu started spearfishing in Pt Phillip in the early 1960s, and never really stopped
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PostPosted: 09 Nov 2012, 13:15 
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Great article and very nice looking gun Ric!

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PostPosted: 10 Nov 2012, 01:08 
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Thanks Ric you're a bloody champion.

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PostPosted: 10 Nov 2012, 10:41 
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'Onya Ric!!

Excellent photo's and instructions.


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PostPosted: 28 Feb 2014, 13:28 
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agreedddddd


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PostPosted: 01 Jul 2014, 00:40 
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This is awesome Ric, I made an account here just to thankyou. When ever someone asks me about gun building I show them this thread because it shows that you don't need a great deal of tools or expensive parts to build your very own speargun.
Thankyou


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PostPosted: 06 Aug 2016, 17:35 
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Perfect tutorial with images, Could I try this? I have some wood and old furniture which I can use for experiments!

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