Carbon Fiber Mold Help

[Cartierusm]

So I want to make some carbon fiber molds. I know nothing about molds but this seems pretty straight forward, I hope.

Lets say I make a Rhino file of the inside of the mold (the negative) and machine that out. Would be simple enough to make the positive using the same file, just using the opposite side of the surface, but when machining tell RhinoCAM to machine "stock" in the negative? So it fits into the negative with enough room to compensate for the thickness of the carbon fiber and resin?

So Just lay it up in the negative and press the positive into it? Thanks.

[racecomp]

So you are trying to make a pressure mould to make carbon parts and not carbon moulds?

You make it sounds so easy!

[Cartierusm]

LOL...I want to make Carbon fiber parts. The molds would be made out of wood or whatever material is required.

[racecomp]

Ok, what type of system are going to use to make your carbon parts in your pressure mould?

Wet lay, resin transfer or pre-preg?

[Cartierusm]

I have no idea. Never done it before, what do you recommend? I assume with the pre-preg I would have to have some sort of oven or autoclave or vacuum chamber? I do have vacuum in my shop but not a chamber.

[High Seas]

My 2 cents:
1. Any experience with fiberglass and resins (in general)?
2. Are you sure you need CF for the parts?

I'd say if answer to #1 is no:
Then try the molding process with cheap-as polyester and fiberglass -- note if your mold is milled out of a foam product - beadboard (white styro) or blue/pink - you'll wanna use epoxy. A little dearer - but better to check the mold and lear before using CF.

If the answer to #2 is, "well. not really - but it looks so cool.." Then think about using BLACK fiberglass -- looks as good and not nearly as expensive as CF.

IF the answer to #2 is, "Yes - I need the higher strength and stiffness of CF. At least You'll know what you are fdoing from 1 above.

Pre-Preg is very nice -- but at a price -- many hobby level projects can be hand lay-up, or vacuum bagged. Vacuum infusion a bit more involved.

Want to share what you want to build?

Hope the 2 cents is worth at least that!
Jim

[High Seas]

Molds -- I'll add the following few cents:
Male - a buck mold , or
Female? If you want to consider a lot of finish work - you could use a make mold - layup outside - the melt the core (bucK) out if its foam -- a lost foam process of sorts.

Again - how much finish work you want to do. This type of process is used by guys building model airctaft/boats/etc fuselages and hulls.
Jim

[Cartierusm]

I don't want a lot of finish work. I'm going to be making some stuff that I could use the black fiberglas, thanks for the tip, but I will be making some things that definately need the carbon fiber. I do have a little experience with fiberglas layup. I'm not sure exactly what's going to be made yet, I just like the look. I have cigar case made out of carbon fiber and it's pricey so things like that.

[racecomp]

There really is no limit to what you can do in carbon, this one of my carbon projects.

[Cartierusm]

Sweet. Back when I used to build custom Motorcycles I always wanted to do carbor fiber parts, but I didn't have a cnc back then.

[Michael.lee]

Cartierusm,

I am not sure what kind of carbon fiber do you mean here ? do you need plastic part that made of carbon fiber filled plastic ? or the part will be made of carbon fiber directly ?

Please let me know, then I might show my suggestions.


Michael.L

[vinot]

Hi boy,

really it s so nice!!! (the bike)

referring molds: I'm using "porexpan" (pp expanded), but basically you can work any material that does not reacts with solvents, so later it can be laminated with no problems. So use the most soft, easily working material.

Then do your mold. Make negative or positive depending on requirements of final part. In my particular case sometimes I must machine positive and others the negative part (look for inserts,if needed,etc) Basically, the fiber laminate face that contacts with mold will have the exact form as mold,while the other side (usually few millimeters) looks like mold smoothly, so it is not exact as the mold.

In my case I prefer an external company to do the laminate, I always use carbon fiber for a hard use, so I need a good laminating (needs pressure, temperature and a good hand to laminate it correctly). But if mechanical propertries are not important you can try it by yourself: in this case I strongly suggest you fiber glass. Vacuum is needed.


Toni