Categories
Cutting

How to Cut Carbon Arrows using Common Tools

Carbon fiber is arguably the most advanced arrow material out there. Carbon arrows are great: they are strong, stiff and light; indeed, the material is basically unbeatable in stiffness-to-weight ratio. But carbon arrows are also a pain to cut properly: they are hard, splinter easily and wear down most normal cutting tools in no time. For good contact with the nock and point, you’d also have to get the cuts clean and square.

Special tools exist for cutting carbon arrows, and will do it cleanly and efficiently. But you may wonder whether also some of the general-purpose tools you already own can be used for cutting arrows made of carbon fiber. After all, ordering a specialized cutter just for trimming a few shafts to length is hardly worthwhile.

In this article, I will tell you how you can cut carbon arrows with three commonplace tools, at least one of which you are almost sure to have at hand. With proper technique, carbon arrows can be cut with an oscillating multitool, a rotary multitool or a plain hacksaw. However, there are many considerations on blade choice and procedure which you should pay attention to get a clean straight cut.

We will cover the three tools and working techniques next. Using any one of them, you should be able to resize your carbon arrows reasonably well. I will also tell why I would not use a miter saw or an angle grinder for this task. But first, a note on health and safety.

Safety precautions

Carbon fiber dust is potentially very bad for your health. To protect yourself from contact with the dust, you should wear the appropriate PPE and ensure adequete ventilation. Specifically:

  1. Wear gloves
  2. Wear safety goggles
  3. Wear a respirator
  4. Ensure proper ventilation: use a spot extractor

If you do not have a spot extractor, doing the cutting outdoors is the second best thing.

Please also note that carbon fiber dust is conductive, and will damage your electrical devices too. This is yet another reason why it is critical to get this dust out of the shop air.

Method 1: Oscillating Multitool

Carbon arrow shaft clamped between pieces of plywood and cut with a Bosch carbide plunge saw blade on an oscillating multitool. A dust extractor head close to the cut removes the hazardous fiber dust straight from the cut.

Carbon fiber arrows can be cut using an oscillating multitool and common blades. Of all the general-purpose tools, an oscillating multitool the quickest and most flexible cutter for carbon arrows: cutting requires minimal setup and the procedure is simple. An oscillating multitool is my personal favorite for cutting carbon arrows.

Procedure for cutting carbon arrows with an oscillating multitool:

  1. Use a carbide plunge-cut saw or carbide or diamond grit blade. A bimetal blade will also work, but the carbon fibers will wear it out quickly.
  2. Clamp the shaft very close to the cutting point. This prevents the arrow from rattling during the cut, which may splinter the shaft. Be careful with the clamping force – too much will crush the shaft.
  3. Guide the cut securely. This can be done, for example, by clamping a wood block to the arrow shaft and sliding the oscillating blade towards the shaft along the block face; see the image above. Alternatively, if you have a drill stand mount for the tool, you can use its controlled feed to make the cut – this is the best option.
  4. Apply only gentle pressure. Aim to remove material slowly for the smoothest cut and least risk of splintering.
Oscillating Multitool
for cutting carbon arrows:
Pros:
+ Quick setup, no jigs
+ Coarser, less hazardous dust
+ Oscillating blade is safest
Cons:
Needs solid clamping
Carbon fiber dulls bimetal blades
Cut not the smoothest

Method 2: Rotary Multitool

Cutting a carbon arrow shaft with a rotary multitool: the tool is clamped to the table and the arrow guided into the cut with an inside corner support, then rotated.

A Dremel and similar rotary multitools can be used to cut carbon arrows. The cutting technique is a bit more complicated than with an oscillating multitool and takes some setup work, but the resulting cut is very clean.

Procedure for cutting carbon arrows with a rotary multitool:

  1. Use any of the grinding cutoff discs available. Thin discs make a cleaner cut and load your tool less, but require more care in guiding and clamping. Some of the HSS circular saw blades work too, but dull fast with carbon fiber.
  2. Clamp the tool to your workbench. Making a square cut with a rotary tool is easier when you keep the tool stationary and move the arrow.
  3. Feed the arrow slightly into contact with the blade. The blade should make only a very shallow cut into the shaft. Keep the shaft as perpendicular to the blade as possible.
  4. Rotate the arrow shaft slowly around. This will extend the cut you made to go around the whole shaft. Be careful to just rotate and not move the shaft axially. Controlling the rotation is easiest when supporting the shaft in a L corner and using an end stop. NB. Remember to rotate the arrow against the cutting direction to avoid disc binding and kick-back.
  5. Feed in a bit and rotate again. Repeating the process will take the cut further in, and finally cut the center line.

For an example of a cutting setup with a rotary multitool, see the photo above.

There is a special restriction in cutting carbon arrows with a rotary multitool: trimming the arrow shaft by an inch or less is easy, but cuts into the middle of a longer shaft are trickier. The reason is that the tool body is usually wider than the cutoff disc and does not allow getting the disc to the cut at a straight angle.

Fortunately, the rotary tool cutoff wheels eat on all faces, and the shaft rotation technique allows you to cut pretty square even if the disc comes in at an angle.

You can also get around the issue completely by using a flexible shaft accessory with the tool: the flex shaft handle is thinner than most cutoff discs, which allows the cutting edge to hit the shaft before the handle.

Rotary Multitool
for cutting carbon arrows:
Pros:
+ smoothest cut
Cons:
needs a jig
slow procedure
fine dust

Method 3: Hack Saw

Carbon arrows can also be cut with the plainest of cutting tools which most people would have: a hack saw. A hack saw is certainly not the optimal tool for the job, but will, with enough care, make a decent cut.

The key to success with a hack saw is picking the finest blade you can find, guiding the blade along a square block, and using very light pressure.

Procedure for cutting carbon arrows with a hack saw:

  1. Use a high-TPI blade for the cleanest cut. The finest of the common blades are 32 TPI, but 24 TPI will still do.
  2. Clamp the arrow close to the cut. Shaft flexure under the cutting forces is even more of a problem with a hack saw
  3. Guide the blade along a square face. Ensure that your cut is square by using a guiding surface on one side of the cut. This surface may be the ends of the vice jaws, a wooden square block or the slot of a miter block.
  4. Apply only gentle pressure on the cut. To avoid roughness and splintering, aim for a slow cutting process that removes as little material with one stroke as possible.

Cutting carbon arrows requires so little force that you might actually ditch the frame and just use the hacksaw blade for the task. Gripping the saw blade as you would hold a scalpel, you can actually easily put enough force for the cut.

Hack Saw
for cutting carbon arrows:
Pros:
+ universal tool
+ coarse dust
Cons:
not as accurate
risk of splintering
slow

Can you use a miter saw to cut carbon arrows?

You may also wonder if you could use your manual miter saw for cutting carbon arrows. After all, it makes precise smooth cuts into many other materials, and can certainly cut square.

In principle, a miter saw could indeed be used for cutting carbon arrows. However, the common miter saw blades are designed for larger and softer workpieces, and are not well-suited for cutting carbon fiber. Specifically, manual miter saw blades have coarse teeth around 14 TPI, which is a bit too low for carbon arrows. Morever, they are not hard enough to last very long in cutting carbon fiber.

That said, if you happen to find a particularly high TPI miter saw blade (30 TPI or above) and do not mind it dulling quickly, a manual miter saw makes a great carbon arrow cutter. Whether of the free blade & miter box or guide rail type, the miter saws allow for cuts that are both clean and square. As with a hack saw, remember to

  • clamp the arrow to the miter box or saw frame close to the cut
  • apply only a gentle pressure and use light strokes

Can you cut carbon arrows with an angle grinder?

An angle grinder is the master of hard materials, and there is one to be found in almost every garage and workshop. Could you use it to cut carbon arrows?

Technically, an angle grinder will easily cut any carbon fiber arrow shaft – indeed, it will cut through like butter. However, making the cut clean, square and safe at the same time is difficult, so an angle grinder cannot be recommended for cutting carbon arrows. Simply put, it is too rough a tool for this fine job.

To start with, most angle grinder cutoff discs use rougher abrasive grains than those in Dremel cutoff discs. These rough grains will tear and score the arrow shaft much more, and do not leave a smooth finish.

Second, even if you find a fine-grained cutoff wheel for the grinder (thin ones are a good place to start looking), making the cut square is challenging. In principle, you could use the same shaft rotating technique as with a smaller Dremel-type tool. But with a much more powerful angle grinder, this technique is not very safe: your hands are close to the wheel and on the wrong side of the blade guard.

You could of course clamp the arrow shaft and cut handheld with the grinder as you normally would. However, making the cut square this way is very difficult, and this approach not really viable either.