Carbon fibre how many layers

Aluminum expands and contracts substantially from thermal changes, while carbon fiber hardly changes at all. Imagine making an engine with a carbon fiber block, heads, pistons, rods, rocker arms, etc.

If every link in the chain was carbon fiber, your valve lash would be the same on a cold engine as it would in a hot engine, and your piston rings would require zero gap. As far as machinability, billet carbon can be machined like aluminum, it just takes different tooling. Nearly anything that can be made of aluminum can be also made of carbon fiber. Some things just take so much engineering effort, or cost so much to build each individual item, that it no longer becomes practical.

Carbon fiber is much more stiff and rigid than plastic components. Carbon fiber is 50 percent lighter compared to aluminum. Front Street: There are quite a few different weave patterns. Can you explain the differences between the choices?

Which are the most popular for automotive applications, and why? Some weaves are made to look cool, while some are made for a specific purpose.

It is a compromise in strength in all directions. It is the material you usually see and what most people associate with, as carbon fiber. After those two, you have the purpose-built directional and unidirectional fabrics. A carbon fiber driveshaft is made of unidirectional carbon fiber that wraps around in a circle shape. In other words, the tow that we talked about in the first question are all resisting twisting forces because they are all laid in the same direction to resist the twist.

These driveshafts commonly resist forces applied in excess of 2, lb-ft of torque over and over and over again. However, if you smacked that same driveshaft on the side of it with the face of a metal framing hammer with probably less that pounds per square inch of force just once, you would probably damage it beyond repair.

It shows more depth to a formed part, which is often desired by the consumer. Front Street: In the case of automotive panel production, molds are made to ensure each piece matches the OEM panel.

The mold is the single most important part of the process to building quality body parts. It all begins with the mold.

First, you must begin with a quality part. So, find the nicest part you can get your hands on, regardless of price, and make it nicer. Then you install flanges on the part and fill any holes. So, we take our time with the glass work. No sense ruining all that other work just to save a day or two. Once the mold is done, we dry sand, wet sand and then buff the mold. This is an extremely time-consuming process that begins with grit paper and hits every step of sand paper from 80 to Once we reach grit, we do a three-step buffing process on the part, and then we can wax it eight times before laying up the first part.

All told, we end up spending somewhere around hours of shop time building one set of door molds from start to finish, if we have zero work to do on the actual parts themselves.

As you can see from that, a large expense of doing very high quality parts is in the mold work. This is the reason why lead times of six months to a year on mold work is common. This is the only way to ensure factory fitment and quality of the carbon fiber panel. The billet mold has less chance of warping and shrinking when high heat is curing the piece. Billet molds are created by digitally scanning the prototype to a CAD file, and then CNC-machining the billet aluminum to a modulated multi-piece mold, which creates extremely high cost for carbon fiber tooling using this process.

Front Street: Is it necessary to replace a mold to ensure accuracy as the mold wears? We build our molds to live to 50 pulls. That means we should be able to pull 50 parts out of a mold before it needs to be replaced.

Some parts are harder on the molds and make that number lower, some parts, we can get or more pulls from. And other molds for things like the seats we make, can be repaired or recoated over and over because there is no OEM shape for them to adhere to.

Depending on the material of the tooling molds, and how many units of the part that you have plan to be reproduced.

Most of the single billet mold will last 4,, units before you needed a new tooling. A single composite tooling mold will last about units. But if you using a composite mold, you will need at least five molds to complete this production. Front Street: What extra steps are taken throughout the panel creation process to guarantee accuracy from your product?

Also, making the mold thick and rigid keeps it from bending or twisting while stored. A hood mold usually weighs about pounds or more. This is common with hoods and door skins especially, so we check them frequently against the original part. Most of the customers we serve are building year old muscle cars, so every darn car out there is going to be a little unique. Measuring and documenting the factory panel thickness, making the final product to the same thickness and spec to the factory piece.

Clip and tab locations are the same as the original factory component, and we reuse all factory hardware with the carbon fiber piece. All these steps are to ensure and guarantee the OEM fit on all our carbon fiber components.

Front Street: Are there any specific products which require more tedious manufacturing processes than others might? Even two different door skins are different. Inner door panels for our stock-style doors are pretty tedious. They take a day to do each inner panel and about 35 individual pieces of carbon fiber. Individual tabs and clips need to be positioned and glued to the carbon piece that matches the OEM location, which is an extremely time-consuming process.

You could have three guys making the exact same hood out of the exact same mold, with the same number of layers of carbon fiber, and one turns out heavy and brittle, one turns out like limp spaghetti, and one is perfect. The resin plays a big role in that. There are as many different resins out there as there are paint codes for new cars. There are also dozens of different choices for core materials out there.

When working with carbon fiber though, you really want to work with a core material designed for use with carbon fiber in the environment the part will be used in. The core material we usually use is actually more expensive than the carbon itself.

Epoxy has a slight, sickly-sweet smell which doesn't bother most people, and cures to no smell at all within 24 hours; polyester resin smells absolutely, mind-bogglingly terrible, and will continue to do so for upwards of a week before it fully cures.

I've always used West System epoxies , with very good results. For most purposes, you'd probably want to use Slow Hardener you use their Epoxy Resin no matter what hardener you choose. Joined: 28 Jan Posts: 58 Likes Received: 0.

I would do one layer CF backed by layers of polyestor mat! Though there are now UV-resistant clear coats but they probably cost alot more! But back to the original question, Use 1 layer carbon fiber and feinforce that with polyestor!

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Thanks to both of you Apologies for starting an unnecessary thread. I had being doing some grinding and taking the necessary precautions. I am assuming that a machine shop will cut the slot for me. You must log in or sign up to reply here. Show Ignored Content. Similar Threads.

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