If you don't have the right tools and knowledge, drilling carbon fiber is a difficult task that will results in bad parts and ruined tools. In this post we will go over the good, better and best ways to drill carbon fiber and not ruin your parts or tools.
Safety First - Use Protection
Carbon fiber dust is an irritant and can cause major itching if gets on your skin or difficulty breathing if you inhale it. Proper safety equipment will help prevent this. The following PPE is recommended.
- Long sleeves or a Tyvek paint suit
- Gloves – nitrile is ok, but leather or mechanic gloves are better when cutting or using power tools
- Dust mask or respirator
- Good ventilation, rigging a shop vac or using a downdraft table to collect the dust is better
- Eye protection, especially when using power tools
Spending a little time up front for good preparation is an important part of producing quality parts, and it will save time and frustration later. These following tips will help.
- Tape Measure, remember to measure twice and cut once!
- Masking or painter’s tape, good for outlining where to cut, or allowing you to make more precise marks
- Marking tool, a metallic silver Sharpie works great directly on the carbon fiber, or you can use a pen or pencil on top of the masking tape
- Backing material helps get nice parts and reduce backside blow-out and splintering. You can use wood or rigid foam insulation to clamp your carbon fiber sheet to.
The "Good" Way
Most of you already have an electric drill laying around, this is the simplest way to make holes in carbon fiber. You also probably have a set of high-speed steel (HSS) bits, these will work OK if they are sharp but they will dull quickly. A brand new bit will hold up for 5-10 holes before it is completely dull and will only serve to heat up and burn the resin. Drills that have a speed selector for higher RPM, like the DeWalt electric drill below are a good place to start.
The "Better" Way
If you are planning to drill more than 5-10 holes and don’t want to keep buying more HSS drill bits, there is a better option for great drill bits designed for durability and everyday use. These drill bits have tips that are coated with carbide or diamond which makes them harder and longer lasting than normal steel bits. Carbide tipped bits are reasonably priced and can be found at many places such as McMaster-Carr, which is a great resource for tools and hardware.
The "Best" Way
The best bits for drilling carbon fiber are solid carbide or diamond. These bits are very brittle though and should only be used in a rigid setup like a drill press or mill. If you try to use these with a hand drill, even if you use drill bushings, they can easily shatter. These bits are made to run at very high rpm (3000-5000rpm) and basically just turn the carbon into dust (make sure you are using protection!). Sometimes called brad-point drill bits, they cut fibers without fraying or delaminating the material and they eliminate splintering on both sides of the hole. These bits are incredibly durable and can withstand hundreds of holes if used properly.
Putting masking tape over the area you want to drill allows accurate placement of the hole and helps reduce fraying of top surface material.
Running the drill at high RPMs (3,000-5,000) and a slow feed-rate, or low pressure, will reduce the possibility of delamination and splintering.
Good luck on your project and let us know if you have any other questions in the comments below.
If you have other tips or tricks that work well for you we would love to hear them.