Hello from a strange, faraway planet....

[emisnug]

Well, I’m Rob.

Hi.

Now, I do love composites - have a particular fondness for a good 2x2 twill weave CF. That all being said though, I have worked very little when it comes to small, intracate things. Which is why I’m here. I’ve got a bit of an intulectual dilemna:

If you look at the attached files, this is the foregrip of a little something I’m working on. All well and good, but I have no idea how to make this very intracate shape out of carbon fiber.

Some of the problems:

It’s got a huge hole down the middle of it.
Fillets.
At the thinnest part, it’s only 2.75mm
Plus, it has to contain 300psi. I know it does in aluminium - carbon though? The pressure in contained in the form of a screw-cap in the bottom of the piece. I don’t even know if you can cut threads in carbon fiber.

Any sorts of guidance would be a huge help. This is the most intracate thing I’ve even considered doing in CF.

Rob

[canyon]

Welcome to the forums Emismug. Your questions are all great and I’ll post what I know from the best of my knowledge.

The pressure requirement is significant and will require some careful placement of fibers. FRP’s are reall good at containing pressures as evidenced by scuba tanks and other FRP pressure vessels but you gotta plan carefully.

As for the threading you typically can’t directly thread FRP composites especially if its a loadbearing thread. I’d advise putting an insert in of some sort.

[emisnug]

Welcome to the forums Emismug. Your questions are all great and I’ll post what I know from the best of my knowledge.

The pressure requirement is significant and will require some careful placement of fibers. FRP’s are reall good at containing pressures as evidenced by scuba tanks and other FRP pressure vessels but you gotta plan carefully.

As for the threading you typically can’t directly thread FRP composites especially if its a loadbearing thread. I’d advise putting an insert in of some sort.

Careful placement of fibers… That sounds difficult. I’ve got a carbon-wrapped tank next to me at the moment, and it looks more epoxy than anything else. I honestly have never made a pressure vessel out of CF, but was thinking that I would simplify the design a bit and just use two tubes, then a series of oversized, laser-cut panels over the top so as to mate it to the body and to refine the look of it (lots of hand sanding, then sealed with epoxy and made shiny. would that work?)

Also - putting an insert in. I would assume that I can’t drop a piece of aluminium pipe in and just seal the carbon around it. Does it need a “landing area” of sorts so as to increase the surface area that the epoxy can adhere to? I really want to expand on what the project is about, but I don’t want it nicked (years of design work!), but wouldn’t mind discussing it through Private Message.