New gun build

[foxfish]

I have had this idea about building a carbon fibre gun.
I wanted to make a split mould that could be re used but it has taken a lot of thought to get this far!
I have built several wooded prototypes to test for buoyancy & get the dimension about right.
The gun will eventually become a semi enclosed track with a full band stretch but a handle set about 200mm forward.
Anyhow see if you can make any sense of these pictures

 

[foxfish]

I have made two identical halves from the mould, next I need to make the center strip that will also contain the track...
In the last pic you might be able to work out how I have compressed the foam insert to get a really good finish on the carbon against the mould.

 

[Magpie]

I don't know about anyone else but I can't quite figure out how you're using a mould to produce that form mate?

The shot from the back looks like the two halves are tubes, are they formed round something? How are they then joined together around the track?
How will the handle be attached? They look very thin, are you sure they'll be bouyant enough?

Questions, questions, questions!

 

[foxfish]

Very thin, very strong & very buoyant - only 20mm thick.
Yes I have made several prototypes so I know it will balance = pretty clever huh - LOL

 

[alcap]

A real good idea , and an outstanding realization!! Chapeau

 

[theonetruerat]

Pretty slick.. . .

I'm very curious and very impressed. I don't have near the ambition for a project like that.

What are you using for your mold?

 

[foxfish]

I first of all built a softwood template, I decided to use angles rather than rounds to get the shape.

I then had to paint the wooden gun shape & wax it up so I could cast a fiberglass mould over exactly one half
.
The concept is to make a thin profile gun that has a 1000mm gun, band stretch but with a forward set handle to give the feel & manoeuvrability of a 750mm gun.

Long way to go yet though as this has already taking some time!

I will try & put up a diagram of how I get a tube shape from an open top mould later today.

 

[spaghetti]

Badass!

 

[foxfish]

OK lets see if the pictures help explain ... obversely staged pictures apart from the last one thats on the next post down!

 

[foxfish]

Last two pics ...

 

[Magpie]

Ah I see, very nice. More questions!

Does it come out of the mould easily? Some sort of release agent?

What thickness does the carbon end up being?

How are you going to seal the ends?

Once set do you have to do much trimming along the edges of the top strip to tidy it up?

What track are you going to use?

 

[foxfish]

I have bought a 10mm od - 8mm id carbon tube for the track.
The parts release quite easily after 4 -6 coats of special wax.
Minimal trimming required because the taped piece of wood is a very snug fit.
I used 3 x carbon weave & 3 x glass fiber weave to get about 1.5 mm thickness, the foam is quite high density & very compressed.
I cant physically push in the carbon with my fingers!
Loads of other moulds to make - one for each end, center piece with track, handle & trigger linkage! phew!!

 

[Don Paul]

Great write up and images, that is going to be one slick gun...no autoclave, prepreg and inflatable blatter needed in that work shop.Here's to wet and wild.:friday

Cheers, Don

 

[azapa]

Foxy, I am being thick here, but where/when in your process above did you add the resin?

 

[foxfish]

I did say the pics were staged mate lol.
I used epoxy resin, I wish I had weighed out the resin as one half does seem ever so slightly heaver than the other.

 

[azapa]

ok Foxy, but when (in between what photos for example) did you put the resin in? and how? Is the mat "apply carbon weave" put in pre-soaked?

 

[foxfish]

I applied resin to the mould, then laid in a length of cloth weave, I repeated this process - resin, cloth, resin, cloth.
I laid in the glass fiber cloth dry on top of the wet carbon & just stippled it in until it became transparent.
Then the foam was squeezed in on top of the wet layup & the lot clamped up tight for 24 hours.

 

[Magpie]

Why did you put the fibreglass matt in and not more carbon? Does it make it less brittle?

 

[Jonny250]

Well done Mart.
Do you have a hoover?

 

[foxfish]

Each half requires 3 x mts of 75mm carbon weave tape @ £5 mt - glass weave 75mm tape cost £10 for 50mt.
I could & might use all carbon for another gun but this one is still a prototype.
Still I think there will be at least £100 of materials per gun including spear trigger bands epoxy etc - maybe £120?