Carbon Fiber Speargun Build step by step

[GRAPHITE SPEARGUNS]

Hello everyone after reading and re reading many forum posts on gun builds I have decided to finally upload an ongoing build I am currently working on.
All my gun builds start with a computer model. I go through many many many iterations to come up with something that I like and find worthy of building. During the computer process im looking at what im building (this one is a inverted roller with rear roller) and how i can make it. Everything is scrutinized and re imagined to work with a 3d printed optimized for a carbon fiber process.

All those little lines are different versions of spearguns i go through to create a final design. This is only 1 file of many.

With a design chosen i can mock up bands, rollers, handle, screw holes, trigger, muzzle, line guides and anything that need some thought before actual building begins.

With the design finalized i can finally make some physical stuff.
First is the mould for the body, because my 3d printer is not 1200mm long i have to chop the mould up into several bits and join them post printing i had the brilliant idea of adding a location hole for a wooden dowel to be inserted into but later found out this would be to difficult to pull off as the dowel was not consistent size, a bit bendy and glue would all get pushed off when inserting into the hole.

so I decided to place them all in a line and epoxy them together.
For people following along 3d printed in PLA .6 nozzle, .3 layer height, enclosure (important) a lot of time took almost a week to print it all!
POST PROCESSING is written in caps as it is literally the most most most i repeat most important part when it comes to a carbon fiber mould (in my opinion)

First glue all the pieces together mine was done on top of two shafts to keep the with the spearfishing theme and they seemed pretty straight.
After the epoxy is dry (24 hours no excuses) the plastic is sanded with 40 grit to take of high spots, imperfections and better adhesion to epoxy top coat.
Epoxy is then applied with a black die so when i sand it back i dont go to deep into the plastic. This epoxy coating is used to help demould the carbon from the mould if this epoxy coating is not there the carbon will stick to the mould and you will have to destroy the mould (ask me how i know).
Next is wax, i use a my hands with glove to apply the wax leave it on for 10 mins then buff it off do this 5 times or you will have problems (with me)
I also applied PVA (not the glue) for this first use but for my next builds i can just use wax.
Weight each mould so you know exactly how much carbon to epoxy ratio you will use

Carbon Fiber, please wear a mask
For the people who are interested in the process i am doing a WCM (wet compression moulding) process this process is usually reserved for high pressure high heat steel moulds but i have plastic some clamps and a dream.
Carbon used 200 gsm twill 300 gsm uni directional.
The layup is different for the top skin and bottom, because this is an inverted roller most of the bending forces are applied to the top skin thus more carbon for the top.
layup for top is twill x4 uni x1 twill x1 uni x1 twill x2
layup for top is twill x3 uni x1 twill x1 uni x1 twill x1
I also add local reinforcement layers to trigger area, bolting areas and muzzle.
The carbon is layered on using spray adhesive and pressed into all the corners for each layer.
I compress each layer with the male mould to compress and also test that im still able to push the fibers without messing up the side walls.
The last layer of twill i try to keep a good amount of over hang as this allows the side wall to not be squished from the male mould pressing down.
Now its time for epoxy if you remembered to weigh your mould after the post processing stage you can get the perfect 50 50 ratio of carbon to resin, I like to do 60 resin 40 carbon as spearguns dont have to be that light weight and need good compression strength (epoxy).
I recommend not using west but a good carbon fiber laminating resin as west can be to thick. Pour the resin in small amount at a time and press the resin into all the corners with a brush. No photos as resin laminating is stressful af.
After the resin has fully saturated the carbon slap your male mould on and clamp it up!

after 24 hours because of all that beautiful post processing your mould will pop off with with minimal effort.
trim it up (wear protection please)
and see if the skins fit together.

i am currently up to this stage of the gun and will post periodic updates as i go!
if you have any questions please ask and ill try answer to the best of my knowledge!

 

[popgun pete]

Over on Spearboard a few years ago some guys were making a carbon fibre gun, so maybe you could search there to see if you are travelling in the same directions as they were. From memory the guns used a foam core and lay up construction and vacuum bagging. I am not an expert on carbon fibre work, but Diving Gecko is and he had a few projects on the go which he wrote about here. I have not heard from him for some time, he used to be based for work in China. I do know carbon fibres can be hazardous in terms of dust and fine filaments and the resins used in terms of their vapours. One job I had was located near a carbon fibre experimentation area, the workers entered through an airlock and wore what looked like space suits, the area was plastered with warning signs advising against unauthorized entry.

I remember this one, just found it again. https://spearboard.com/showthread.php?t=96618

 

[GRAPHITE SPEARGUNS]

Over on Spearboard a few years ago some guys were making a carbon fibre gun, so maybe you could search there to see if you are travelling in the same directions as they were. From memory the guns used a foam core and lay up construction and vacuum bagging. I am not an expert on carbon fibre work, but Diving Gecko is and he had a few projects on the go which he wrote about here. I have not heard from him for some time, he used to be based for work in China. I do know carbon fibres can be hazardous in terms of dust and fine filaments and the resins used in terms of their vapours. One job I had was located near a carbon fibre experimentation area, the workers entered through an airlock and wore what looked like space suits, the area was plastered with warning signs advising against unauthorized entry.

I remember this one, just found it again. https://spearboard.com/showthread.php?t=96618

I think ive seen most of the carbon builds on SB but would love to be proven wrong.

Would be great to bounce ideas back and forth with the carbon stuff im sure changing small things here and there will end up with a dramatically better end product.

In my opinion foam core and hand layup construction can work but not a very good method for spearguns, there are tight tolerances that must be adhered to eg trigger, shaft rail, and the heights these parts sit at on the gun, a female mould allows for all these tolerance and you can have a dimensionally accurate outer skin to line up jigs for holes. you can also make the carbon layer much thicker and do local reinforcements i find many more pros to a mould than foam core.

Carbon is basically a lot of very fine filaments. because they are fine getting into airways and even onto the skin is not advised.

 

[GRAPHITE SPEARGUNS]

I made these solid blocks of carbon using the "forged carbon fiber" method to allow for a Trigger box, roller reinforcement, and anchor points for bolts or screws required in a inverted roller. The carbon skin is thoroughly sanded with 40 grit sand paper for good adhesion to the epoxy and epoxied into place. I find the addition of these solid blocks allow for transfer of forces between the top and bottom skin and also adds to the torsional stiffness of the body.
they also provide good locations to clamp onto when joining the skins together.

The skins are also made in the mould to allow for a joggle joint of 5mm the skins are much strong with a joggle than a simple butt joint i would not want to buy a speargun that is constructed with a butt joint as this is a very big weak point and carbon fiber has a tendency to fail very dramatically when forces get a little to much.

to join the skins together i reuse the moulds. reusing the moulds is important as this locates the skins in the correct position, the shaft track is also straight in the mould and does not deviate from the clamping pressures. then its a matter of plastering on a even amount of epoxy tinted black onto the edges of the skins applying even clamping pressure and waiting.

When the monocoque has been complete the over lap of the skins is usually a little to much for me and this need to be sanded back to make the body of the gun the proper profile shown in the computer model.
At this stage the small accessories can be tested to see if they fit because all this was done on a computer first most of the tolerances are very good and only very small adjustments need to be made.

 

[popgun pete]

I think ive seen most of the carbon builds on SB but would love to be proven wrong.

Would be great to bounce ideas back and forth with the carbon stuff im sure changing small things here and there will end up with a dramatically better end product.

In my opinion foam core and hand layup construction can work but not a very good method for spearguns, there are tight tolerances that must be adhered to eg trigger, shaft rail, and the heights these parts sit at on the gun, a female mould allows for all these tolerance and you can have a dimensionally accurate outer skin to line up jigs for holes. you can also make the carbon layer much thicker and do local reinforcements i find many more pros to a mould than foam core.

Carbon is basically a lot of very fine filaments. because they are fine getting into airways and even onto the skin is not advised.

On Spearboard we discussed carbon fibre guns a number of times. I wrote to Carbon C4 asking them how they moulded their guns in terms of pressurising the internal bladder which remains inside the gun after it is removed from the mould. We already knew the bladder was still inside as someone had sliced the front off a damaged C4 gun and shown us a photo of the cross section. C4 replied that they pressurised the gun through a hole which they fill with a plug under the reel mount base, where none of us thought to look.

When carbon fibre guns first came out it was all about lighter guns with a carbon fibre pipe, odd when a gun needs some mass to handle the recoil. Now monocoque construction carbon fibre guns are heavy, which makes more sense if they need to use heavier shafts and more band power. You can think of carbon fibre as compressed timber with a void inside it, the carbon fibre is the wood fibre filaments and the resin is the glue impregnated through it. The big difference is the fibres in carbon fibre can be woven into straps and sheets and we control the alignments. It is in a way like plywood where timber is modified to create lighter, but stronger structures.

I have a C4 Urukay which is a very heavy gun and one of Seal's (Kosta, Kostadin Kanarov) inverted rollerguns which is not quite as heavy. These guns are a long way from the Rabitech carbon barrel Arbalete style guns that started the carbon fibre fad.

 

[GRAPHITE SPEARGUNS]

On Spearboard we discussed carbon fibre guns a number of times. I wrote to Carbon C4 asking them how they moulded their guns in terms of pressurising the internal bladder which remains inside the gun after it is removed from the mould. We already knew the bladder was still inside as someone had sliced the front off a damaged C4 gun and shown us a photo of the cross section. C4 replied that they pressurised the gun through a hole which they fill with a plug under the reel mount base, where none of us thought to look.

When carbon fibre guns first came out it was all about lighter guns with a carbon fibre pipe, odd when a gun needs some mass to handle the recoil. Now monocoque construction carbon fibre guns are heavy, which makes more sense if they need to use heavier shafts and more band power. You can think of carbon fibre as compressed timber with a void inside it, the carbon fibre is the wood fibre filaments and the resin is the glue impregnated through it. The big difference is the fibres in carbon fibre can be woven into straps and sheets and we control the alignments. It is in a way like plywood where timber is modified to create lighter, but stronger structures.

I have a C4 Urukay which is a very heavy gun and one of Seal's (Kosta, Kostadin Kanarov) inverted rollerguns which is not quite as heavy. These guns are a long way from the Rabitech carbon barrel Arbalete style guns that started the carbon fibre fad.

A bladder mould would be the strongest method of constructing a monocoque speargun as there would be no join but also the most difficult as a mould not made strong enough would lead to outward explosions. not very diy friendly.
is there a photo of the c4 cross section?

i think the benefits of carbon fiber for a pipe gun is that it is lighter and stiffer, lightness allows for heavier shafts to be used while keeping the pipe the same diameter still allowing the gun to float and change buoyancies with added weights. I think Rob allen found the limits of this and thus the timberline gun was made.
Pros of the custom shape carbon gun is i can control buoyancy with the addition of very small amounts of lead, shape also allows for band tucking forming streamline shapes for tracking even with many sets of bands for an invert.

Could you measure the length and weight of the urukay and seal's gun all rigged up, the gun below is a invert roller 6 individual bands 1171mm long from tip to butt 7.5mm pathos shaft and weighs about 1.6kg

 

[popgun pete]

Well they are the exact same lengths, but are not rigged up right now. The spear in Seal's gun is the original, when I bought it the spear had to be left out in order to ship it, so I used one of my own. Many months later I was able to retrieve it and as you can see it is unused. The muzzle does not have its line wrap pins which I took out again for storage. A pin type shaft, not my usual choice, but Kosta knew what he was doing.

Muzzle to butt the guns are both 5 foot long, not including the spears.

Carbon Fiber Gun structures - Spearboard.com - The World's Largest Spearfishing Diving Boating Social Media Forum

Carbon Fiber Gun structures All About Guns

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https://forums.deeperblue.com/threads/c4-graphite-accuracy.116823

Carbon C4 section showing remains of inner bladder.

 

[popgun pete]

Present and past guns that all do the job.

 

[GRAPHITE SPEARGUNS]

Well they are the exact same lengths, but are not rigged up right now. The spear in Seal's gun is the original, when I bought it the spear had to be left out in order to ship it, so I used one of my own. Many months later I was able to retrieve it and as you can see it is unused. The muzzle does not have its line wrap pins which I took out again for storage. A pin type shaft, not my usual choice, but Kosta knew what he was doing.

Muzzle to butt the guns are both 5 foot long, not including the spears.

Carbon Fiber Gun structures - Spearboard.com - The World's Largest Spearfishing Diving Boating Social Media Forum

Carbon Fiber Gun structures All About Guns

spearboard.com

https://forums.deeperblue.com/threads/c4-graphite-accuracy.116823

View attachment 59478
Carbon C4 section showing remains of inner bladder.

Kostas Gun is beautiful i can tell just by the photos the work that must have gone into that gun.
the section through the c4 is quite shocking i didnt really expect such shoddy construction the bottom has a nice curvature of carbon but the top half is very bad almost like something went wrong when expanding the bag. i think c4 being a bigger company should have better methods to there carbon fabrication. im guessing all this has also been fixed to.

Great collection of guns pete!

any scales around for gun weights?

 

[popgun pete]

Kostas Gun is beautiful i can tell just by the photos the work that must have gone into that gun.
the section through the c4 is quite shocking i didnt really expect such shoddy construction the bottom has a nice curvature of carbon but the top half is very bad almost like something went wrong when expanding the bag. i think c4 being a bigger company should have better methods to there carbon fabrication. im guessing all this has also been fixed to.

Great collection of guns pete!

any scales around for gun weights?

I have, but these are not easy guns to weigh, closed muzzles would be a different story. Maybe later.

 

[GRAPHITE SPEARGUNS]

Carbon fiber handle, to be more precise wet hand lay compressed carbon handle with plastic core.
once again start off with the design in computer.
i tried many different designs with the handle but ultimately ended up with a standard design handle that fits my hand slightly better than the on the shelf units. because this gun is an inverted roller with much less recoil and will be used it both semi blue water and close up reef situations i decided to not go with a anatomic handle. many prints at full size was used to determine best shape and angle for my preferences.
after a shape is determined the mould can start to make shape.
as you can see by the images it is a 4 part mould 1 core a left and right piece and a top piece all have been designed with location holes for m6 bolts.
the second image shows the 1.2mm gap where the carbon will take place.

then once again post processing work! the moulds come off the printer white, the black is an epoxy coat sanded down to 2000 grit with 5 layers of wax i added a layer of pva for the first go i will only add wax for next pulls. the image below is after everything has been done and cured and i have pulled off one side of the mould. the image on the right is the handle with no post processing straight out of mould.

i think this process of making parts out of carbon and 3d print make extremely strong products for relatively little work.

 

[popgun pete]

I think it would be instructive if you show everyone the gear you use while working with this stuff. Some years ago I remember a guy who was making one off items for himself and he basically was doing it like he was in a wood workshop. He never realized the implications of the stuff he was breathing in and was quite surprised that there is a downside if you are not geared up properly. What sort of gun volume would you be looking to produce? As you know there are a number of carbon fibre guns available, but some are better than others, a lot being churned out in Eastern Europe. The Cetma Canova guns come to mind and they have been discussed here before. Like Kosta they use a band battery tunnel on the gun, this is the most effective use of this material as it would be difficult to make such a cross section in timber and have the strength. The band battery tunnel improves the gun's lateral drag on the traverse, only the top deck cables can thrum and being small diameter they usually don't.

Looks like it was on Spearboard, but pretty sure it got looked at here as well.

Canova 95 Carbon speargun - Spearboard.com - The World's Largest Spearfishing Diving Boating Social Media Forum

Canova 95 Carbon speargun All About Guns

www.spearboard.com

 

[GRAPHITE SPEARGUNS]

I think it would be instructive if you show everyone the gear you use while working with this stuff. Some years ago I remember a guy who was making one off items for himself and he basically was doing it like he was in a wood workshop. He never realized the implications of the stuff he was breathing in and was quite surprised that there is a downside if you are not geared up properly. What sort of gun volume would you be looking to produce? As you know there are a number of carbon fibre guns available, but some are better than others, a lot being churned out in Eastern Europe. The Cetma Canova guns come to mind and they have been discussed here before. Like Kosta they use a band battery tunnel on the gun, this is the most effective use of this material as it would be difficult to make such a cross section in timber and have the strength. The band battery tunnel improves the gun's lateral drag on the traverse, only the top deck cables can thrum and being small diameter they usually don't.

Looks like it was on Spearboard, but pretty sure it got looked at here as well.

Canova 95 Carbon speargun - Spearboard.com - The World's Largest Spearfishing Diving Boating Social Media Forum

Canova 95 Carbon speargun All About Guns

www.spearboard.com

in my opinion the one thing that has to be worn no excuses is a good respirator with replaceable filters NO MASKS (they dont fit your face). i find myself using different PPE (personal protection equipment) for different situations, if im using a rotary tool and i know im going to be flinging particles everywhere i run a respirator, gloves and some disposable coveralls. i always run a shop vac when using a rotary tool or any other power tool when sanding direct carbon fiber. if im hand sanding carbon fibre i skip the shop vac as i know im going to be running along the body of the gun and will likely pick up nothing i can vacuum after some sanding. the only steps where you need to be careful is the trimming and direct carbon sanding stage after this your only sanding resin which should also be done with care but could be considered much less.

the volume i try to achieve should be mathematically achievable but i have made more than enough guns now to know if it will float or not, i try to make the guns float so i can fine tune with lead.

As you can see in the cross section im also trying to hide bands in grooves one of the many advantages to a carbon speargun.

 

[popgun pete]

in my opinion the one thing that has to be worn no excuses is a good respirator with replaceable filters NO MASKS (they dont fit your face). i find myself using different PPE (personal protection equipment) for different situations, if im using a rotary tool and i know im going to be flinging particles everywhere i run a respirator, gloves and some disposable coveralls. i always run a shop vac when using a rotary tool or any other power tool when sanding direct carbon fiber. if im hand sanding carbon fibre i skip the shop vac as i know im going to be running along the body of the gun and will likely pick up nothing i can vacuum after some sanding. the only steps where you need to be careful is the trimming and direct carbon sanding stage after this your only sanding resin which should also be done with care but could be considered much less.

the volume i try to achieve should be mathematically achievable but i have made more than enough guns now to know if it will float or not, i try to make the guns float so i can fine tune with lead.

As you can see in the cross section im also trying to hide bands in grooves one of the many advantages to a carbon speargun.

View attachment 59494

Actually I should have made that clearer, I was asking about gun production volume, not the gun cross sections, but thanks for the diagram.

When people first began looking at making spearguns with a more streamlined body and a lot of bands that resulted in the cable gun, or more accurately the cable rollergun. The idea was the band battery was buried in the gun body and drive to the spear was via cables or long wishbones, which meant using rollers or pulleys. Their problem was the materials to make such guns were very limited back then, so you were looking at timber stocks.

Australian Ted Egan was one spearfisherman who went this route and his cable gun scored him the Marlin Cup one year for the biggest fish shot. I have never seen his gun, although it is said to still exist, but it was unreliable as parts came adrift and it suffered from jams. Things have changed a lot since then! The inverted rollergun is a reimagining of the cable gun.

 

[GRAPHITE SPEARGUNS]

Actually I should have made that clearer, I was asking about gun production volume, not the gun cross sections, but thanks for the diagram.

Currently big fat zero!

my name makes it look like im a company but because i make carbon guns i decided to name my self graphite spearguns. im more of a hobbiest at this point. maybe in the future with a better production line and much more testing ill put out a product.

 

[popgun pete]

Currently big fat zero!

my name makes it look like im a company but because i make carbon guns i decided to name my self graphite spearguns. im more of a hobbiest at this point. maybe in the future with a better production line and much more testing ill put out a product.

With the amount of work you are doing I think you could certainly sell guns as many of the current guns don't really exploit the advantages of the material, but there are exceptions. My thoughts are more could be done with the material than just make a carbon fibre analog of a timber gun, which many do. I don't need to name them as they are obvious just by looking at them. One radical gun was the C4 Mr Dark which tried to turn the gun into a slim wand with all the buoyancy and drag inducing mass at the rear, but the band drag and thrum was still going to occur. It was a bold idea, but that wand-like barrel is difficult to keep straight, so the gun was abandoned, well for now that is. Guns like the Urukay are going the high mass route, but to be different had a rather misguided muzzle, which showed the company's bicycle frame origins and echoes of the mounting of bicycle gear change levers.

My thoughts are carbon fibre guns should pursue the buried band drive, inverted rollergun route, if you have the band battery cable drive in the open then you might as well use something like the MVD Zeso. Most guns can be made of timber or aluminium tube, but a buried band battery rollergun is not one of them.

By way of contrast the original spring guns had a buried drive system, the compression coil spring in the barrel, and their descendants the pneumatic spearguns also have a buried drive system, but have all or nothing loading, so powerful versions take some effort to cram the spear down into the gun. So far only the band gun has split incremental loading, which is why band guns, besides being simple, are so popular.

The Dreamair Unreal is an imaginative use of carbon fibre, but in my view that gun would be better in alloy, although the all important piston sliding inner tube is aluminium inside the carbon fibre body. It has higher efficiency as lossy rubber band power is eliminated, but it has no split loading, ultimately at its most powerful it takes grunt to load it. Of course you can let air out, it varies its power by how you set it up in terms of pressurization. What carbon fibre construction offers is increased gun mass in the Dreamair, you can launch heavier shafts from it. Heavier shafts increase battle damage on your prey, you bust things, not just skewer them.

 

[popgun pete]

Spearguns are quite simple, but a lot of pseudo science has crept into the discussions as people embrace and repeat things that are plain wrong. For example anything that propels a couple of feet of steel shaft at relatively high velocity must have recoil, the question is can the operator handle it and what makes it easier to handle. The answer is the rate of acceleration that they can withstand and that is basically the gun's jerk. A jerk is the rate of change of acceleration, it is a definition in physics. The heavier the gun the recoil gets ever lower, for example if you had a gun that literally weighed a ton the recoil velocity would be very low, but make the gun not much heavier than the spear then the recoil would be very high. Rollerguns have shock absorbers built into them, on standard rollerguns the shock absorber is the band wrapped on the band roller, on inverted rollerguns it is the drag in the cable pulley drive system which always incurs losses because under load the drag is higher than just free spinning the roller in its moving shackle no matter how good the bearings in the roller are.

 

[popgun pete]

Another thing I should add is the effect of bands running on the gun body. In the early days guns all used hard wire wishbones and these kept the bands standing off the stock with in line pull to the front mounting sockets, but when slotted muzzles were used the bands now ran on an angle to the muzzle. With long guns this did not make much difference as the angle was very shallow. This all went out the window with soft cord wishbones as now the bands ran on the gun body tube and interfered with how they drove the wishbone. To help make matters worse guns lost their closed muzzles and now more variables were at play as the shaft was driven towards the muzzle. In fact the bane of speargun development has been the mindless mix and match of muzzles that work OK in one configuration and not so well in another. This all started when guys look the inline band pull Cavalero Champion Arbalete and put different muzzles on it. They did this to get away from the separate band strand system and they could then use easy to make band loops, but in doing so they partially stuffed up the gun's dynamics. Eventually seeing what the market wanted the makers of those same arbaletes began using the slotted muzzles themselves and that has gone on ever since.

 

[GRAPHITE SPEARGUNS]

My thoughts are carbon fibre guns should pursue the buried band drive, inverted rollergun route, if you have the band battery cable drive in the open then you might as well use something like the MVD Zeso. Most guns can be made of timber or aluminium tube, but a buried band battery rollergun is not one of them.

Yes i always put my guns up to pipe guns and see what the benefits may be. if there is none whats the point.

once again the benefits of computer modelling i know the exact height my drive cord will be, of course in real life this may vary slightly but this can also be adjusted by making slightly larger sheaves. this also allows me to test with various different wheel sizing possibly finding the best cord level in relation to shaft.

 

[popgun pete]

Yes i always put my guns up to pipe guns and see what the benefits may be. if there is none whats the point.

once again the benefits of computer modelling i know the exact height my drive cord will be, of course in real life this may vary slightly but this can also be adjusted by making slightly larger sheaves. this also allows me to test with various different wheel sizing possibly finding the best cord level in relation to shaft.

View attachment 59496

Differences will be miniscule, you would need a wagon load of testing to find any difference, if there is any. Overthinking spearguns is counter productive, I know as I have built plenty of them, particularly as spears are not dead straight and if they are then they don't stay that way.