Can Drilled and Slotted Rotors Be Resurfaced

Yes, drilled, and slotted rotors can be resurfaced. The rotor must first be inspected to determine if it needs to be resurfaced. A new drill bit and slotted flange can be installed if the rotor does not need to be resurfaced. Then if the rotor does need to be resurfaced, the entire rotor must be removed and replaced with a new one.

This article will inform you more about resurfacing drilled and slotted rotors. Read to learn more.

What is the purpose of drilled and slotted rotor? 

Drilled and slotted rotors are typically used on larger helicopters, such as Chinooks and AW109s. Their purpose is to increase the helicopter’s ability to hover by providing more lift at lower speeds. They are also used on helicopters requiring higher precision and accuracy, such as UAVs and medical helicopters.

When a helicopter is flying, air circulates the rotors in circular patterns. The smoother these circles are made, the more efficiently the aircraft can fly. Drilled and slotted rotors help make these circles smoother by creating slots between the rotors.

Why do rotors keep warping?

Rotor warping occurs, generally due to surface roughening. A wrong choice of materials can cause this. Also, these factors and environmental influences can cause the rotor to stretch.

Typically, this will happen in short tractions such as landing and during takeoff roll-up, climb out, and some power off flying conditions on scorching days, especially after washing with a high-pressure washer multiple times (re-wash) or high hours on the airframe. 

Once warping occurs, it will stay until repaired by milling a new lap in at that point in the flange’s curve where anomalies trap and ‘ride up’, allowing a more straightforward approach to a better operating condition again.

Rotor Warping can lead to either rotor blades contacting each other (contact misalignment), which could cause damage much worse than warped rotors themselves; these circumstances usually require complete rotor replacement. Rotor Surface Warping is common, especially on older aircraft; it’s not uncommon to go many years without replacing rotors.

Reasons why resurfacing rotors are concerning

The main concern with resurfacing rotor is that the metalworking fluids used in the process can cause damage to the metal surface. Symptoms of rotor resurfacing that should be observed include decreased braking performance, uneven braking, and decreased rotor life.

If left unchecked, these problems can lead to irreversible damage to the rotor and even a failure of the brake system. It is essential to consult with an expert prior to any rotor resurfacing project to prevent these issues from happening.

Drilled and slotted rotors pros and cons 

There are pros and cons to both drilled and slot rotors.

Drilled and Slotted Rotors are good for flight stability, which can be improved. However, drilled, or slotted rotors have less life span than before. 

Drilled or Slotway rotor decreases the braking capability of the brakes. Without weight penalty above 800 lbs allow a similar loading on each leg of the brake system to an all-stock configuration (if possible).  If you buy your aircraft with these modifications, they will likely remain installed throughout its life.

While rotor blade aeroelasticity allows for larger or smaller radii of the blades than with round metal, increasing those will not increase pitch moments without opening the airfoil.

Therefore, this is redundant mainly design modification, restoring us to rounded symmetrically designed rotors (the most efficient shape) where they were, to begin with. The only thing you can gain by keeping them at their original radii is that there will be fewer yaw effects at various altitudes or perhaps more stable with the ailerons while hovering.

A similar question could apply to slotted rotors (i.e., what is my electrical motor worth in blade area?), which can cost far too much money. Still, their life span should last longer anyways since they are slower and therefore spins generate more heat.

They tend to change heading instead of changing direction as you roll out of turn, which is another oops. They create more drag than if you were flying with round rotors and possibly make you scared of leaving on power. While hovering, they are sensitive when attempting/undertaking whole stick deflections or small collective movements.

Why this standard and why now? There has been a lot of talk regarding installed features and various things people “try” on them

How long do drilled and slotted rotors last?

Drilled and slotted rotors will last for several years depending on how often they are used and how well they are taken care of. Be sure to keep them covered when, not in use and avoid getting them wet. Also, make sure to lubricate them every time you use them to help them run smoothly.

Can slotted brake rotors be turned?

Yes, slotted brake rotors can be turned. However, consult with a mechanic before attempting this if you are not familiar with the process. Rotor slippage can occur if the rotors are not turned correctly and can cause damage to the brake system.

Are slotted and drilled rotors bad?

There is no one-size-fits-all answer to this question, as the benefits and disadvantages of slotted and drilled rotors will vary depending on the vehicle and usage. Some benefits of slotted and drilled rotors include increased cooling performance, better fuel economy, and less chance of wheel spin.

On the negative side, drilled rotors can be more challenging to tune and may require more frequent maintenance.

Additionally, they can be more susceptible to weathering and rusting over time. When it comes to slotted rotors, they can generate more noise than drilled rotors, and they may be harder to remove in a collision.

How many times can you resurface brake rotors?

Rotors can last anywhere from 6,000 to 10,000 miles before being resurfaced. When they reach their lifespan, it is essential to replace them to ensure safe braking. Brake rotors should be resurfaced every 6,000 miles or every 3 to 5 years, whichever comes first.

It is also essential to remember that rotors will become warped if they are not resurfaced regularly. As a result, the braking performance will be reduced, and the rotor may even start to fly off the wheel during braking.

What is the best way to resurface rotors?

Rotors can become resurfaced in several different ways, but the most common is resurfacing with a rotor resurfacing machine. This machine uses a rotating drum to remove the rust, corrosion, and scaling from the rotor surface. It is important to note that resurfacing rotors will not restore their original performance, but it will improve their performance and lifespan.

It is also possible to resurface rotors with a sandpaper or wire wheel method. This can be done by hand or using a rotary tool. The main benefit of this method is that it is less expensive than using a rotor resurfacing machine, and it can be done in a shorter period.

However, the rotor may not be as smooth as possible, and it may not be as durable.

Ultimately, the best way to resurface rotors depends on the type of rotor and the condition of the rotor surface.

Can you resurface motorcycle rotors?

Yes, you can resurface motorcycle rotors. Rotors are one of the most critical parts of a motorcycle, as they protect the engine from debris and damage. By resurfacing the rotors, you can increase the lifespan of the rotor and prevent it from cracking or breaking. Additionally, by resurfacing the rotors, you can improve the braking performance of your motorcycle.

There are a few steps you need to take to resurface motorcycle rotors. The first step is to remove the old rotor. Next, you need to clean the rotor using a degreaser.

After that, you need to apply a new coating of rotor sealant to the rotor. Finally, you need to apply a fresh asphalt coating to the rotor. Make sure to follow the instructions provided with the rotor sealant and asphalt coatings to ensure that the job is done correctly.

Is it Better to Resurface or Replace Rotors?

There is no definitive answer to this question. Ultimately, it depends on the condition of the rotor and the type of rotor that you are using.

If the rotors are in good condition, there is no reason to replace them. However, if the rotors are damaged or cracked, resurfacing may be better than replacing them.

What happens if you keep driving with grooved rotors?

If you keep driving with grooved rotors, you will likely experience brake fade and reduced braking performance. Grooved rotors are typically found on cars used for racing or off-road use, and their purpose is to improve the braking performance by providing more consistent contact with the brake pads.

However, this rotor style can cause brake dust and debris to be created, which can reduce braking performance.

In addition, grooved rotors can also cause noise and vibration, leading to premature wear on the brake pads and other parts of the car.

Finally, grooved rotors can also cause the wheels to wear more quickly, leading to a loss of braking performance. If you find that your braking performance is deteriorating, it is vital to have your rotors inspected and replaced if necessary.

Why shouldn’t you put new brake pads on old rotors?

Putting new brake pads on old rotors can cause your brakes to stop working correctly. This is because the new pads will not be able to grip the rotor properly, and this will cause your brakes to fail.

By replacing your brake pads with new ones, you will be able to avoid this problem and keep your brakes working correctly.


If your rotors are damaged or cracked, resurfacing them may be better than replacing them. However, if you have been using the same brake pads on your drilled and slotted rotors for an extended period without any problems, there is no reason to replace them.

Garry Rodruguez

Hey! It's me, Garry Rodriguez, A researcher. I'm passionate about learning new things & sharing my knowledge with information enthusiasts.

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