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Solar Mike's answer is accurate. Carbon fiber has a resin to fiber ratio which provides the optimum strength. This is typically measured by weight. The amount of resin is applied to the fiber prior to enclosing it for vacuum application. Once the vacuum begins, all of the air is removed from the fiber, forcing the resin into the voids, ensuring the ...


3

You basically can't. The same way carbon fiber is made: Epoxy. Fiber-filled if need be...but won't be as strong as a weld though. The only other potential method I know of is to get carbon fiber composite that uses a thermoplastic matrix like nylon and try ultrasonic or friction welding it. But not only is nylon thermoplastic difficult to find raw, you need ...


3

No, it is not a gimmick. Triaxial weaving has been around for a long time, and can be seen in baskets, hats, etc. etc. It often exhibits superior structural properties such as greater resistance to shear forces, tearing, bursting etc. The sheet will also be generally more isotropic, so if you don't know which direction your forces will be coming from, it may ...


3

Stitching it like Chris Johns mentioned would be a good solution. Carbon fiber is typically sold in a tow (untwisted bundle of fibers), but with a large gauge needle you might be able to get it to work on a standard sewing machine. There will probably be some fuzz to manage as fibers are broken in the process, but would be much easier than by hand. It may ...


3

One solution would simply to hem it as you would any other textile if it's just for the ends of a tube blanket stitch would be easy enough to do by hand and should do the job.


2

First off, think about good old-fashioned injection molds or even lost-wax molds. It's relatively easy to cast complicated single-piece objects. In the case of carbon-fiber fab, it depends a bit on what you call "one piece." Usually the structure is built up out of intricately cut 'fabric' which is coated with bonding fluids to produce an integral single ...


2

a fiber-composite like carbon & epoxy works as follows: The tensile strength is furnished by the fibers and the shear strength is furnished by the resin. Furthermore, since the resin encases the fibers and prevents them from buckling in compression, it also enhances the compressive and bending strength of the part. Fine-diameter fibers possess a lot ...


2

There are two reasons: One is to remove trapped air bubbles and two to pack the fibres as densely as possible within the structure or weave of the fibre pattern wanted.


2

As far as I know, you can't mold a sphere or cylinder unless the material is on the outside of the mold and you keep the mold in place. Think paper machee over balloons. There is no way to get the balloon out. There is no way to get material to the inside of a hollow mold unless you can spin the material onto the walls, which won't work for carbon fiber. ...


2

If I understand correctly, it sounds like you want to make a short carbon fiber tube. This can be done by wrapping the carbon fiber cloth around a mandrel that has the diameter that you want the inside diameter of your tube to be. There is an excellent video that demonstrates the process. Search for “How to make a roll wrapped carbon fiber tube” on ...


1

The material has to be tested for each application as the fibre density, weave and number of layers all have effects on the stiffness. This means even each batch may have a variation so exact values may not be easily available. Some companies are very "expert" in this as they are using carbon fibre sheets in extreme situations and have found what ...


1

The bonding in carbon is directional which means one carbon atom must bond in a fixed way to other atoms, e.g. 4 single bonds to hydrogen or two double bonds to oxygen. In the case of carbon-carbon bonding, you have one carbon to four others in diamond and one to three others in graphite. The bonding in metals is delocalised which means that the metal atoms ...


1

What steel to use? What thickness and width? What angles to use? An inexpensive source of spring steel for experimenting with are leaf springs. You have serious competition, named Keahi Seymour and his 25 mph 'bionic boots'. There are also fictional designs to draw from.


1

Its not about the tension in the final product. [They are claiming] tension during fabrication buys them a much higher fiber loading. See 67 vol%.. a typical "wet layup" is maybe half that. Having the fibers very very straight probably contributes somewhat as well. Note also the 3+GPa claimed strength is for some "micro" composite. If you look elsewhere ...


1

Many pultruded FRP sucker rods are used in oil well pumping. The only pretension is that load used to pull them through the manufacturing process. String design keeps them in tension ( steel rods in the bottom of the string, FRP at the top). I believe this is because the compression properties are relatively poor. For compressive strength , I doubt that you ...


1

No - Pretension can throw off the compression modulus While the properties can be calculated using formulas (depending upon the levels of reliability and degree of design, as shown in other answers on this site), the net result can still be off due to pre-tension in the fibers. Basis: Composites handle tension well, but are terrible in compression. This is ...


1

One approach is to manufacture a core from materials such as rigid foam, expanded metal (aluminium honeycomb etc) other similar low density but rigid materials along with any inserts and attachment points and then cover the whole thing with the appropriate pre-preg cloth. This can then be wrapped in plastic film to seal it and then vacuumed and cured in an ...


1

I would use a low viscosity epoxy dip on the tube end and going/polish with an air flow and mask, when cured with repeated operations as required for surface finish.


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