How to Add and Remove Material from Drone Propellers

Balancing drone propellers is a critical task that ensures smooth flight performance and reduces wear on motors and bearings. Even small imbalances can lead to vibrations, which may affect flight stability, image quality in aerial footage, and overall component lifespan.

In this guide, we explore practical methods for adding and removing material from drone propellers to achieve proper balance. We also share important safety tips to prevent damaging the propellers during the process.

Why Balance Matters

Unbalanced propellers cause uneven distribution of centrifugal force during rotation. This leads to:

• Vibration

• Increased noise

• Reduced flight efficiency

• Potential mechanical failure over time

Proper balancing improves:

• Motor longevity

• Flight smoothness

• Image and video stability

• Battery performance

Tools You’ll Need

Before starting, it’s recommended to have the following:

• Propeller balancer

• Fine-grit sandpaper or nail file

• Transparent or electrical tape

• Cyanoacrylate (CA) glue or nail polish

• Small scissors or blade

• Safety gloves and glasses

Adding Material: For Lightweight Blades

If one side of the propeller is lighter than the other, add material to the lighter blade until both sides stay level when placed on a balancer.

1. Tape Method

Best for: quick adjustments, temporary fixes

• Use a small strip of transparent tape or electrical tape.

• Apply it to the top or underside of the lighter blade near the tip.

• Trim any excess and test again on the balancer.

• Reposition if needed to fine-tune balance.

Tip: Keep the tape surface smooth to avoid aerodynamic drag.

2. Glue or Nail Polish Method

Best for: more permanent solutions

• Apply a drop of CA glue or clear nail polish to the lighter blade.

• Let it dry fully before testing again on the balancer.

• Add more if necessary in very small increments.

Note: Avoid adding too much at once—excess glue can throw the balance off in the opposite direction.

Removing Material: For Heavier Blades

When one propeller blade is heavier than the other, removing material from the heavier side can bring the prop back into balance.

1. Sanding

Best for: fine adjustments on plastic or carbon fiber props

• Use a fine-grit sandpaper (e.g., 400–600 grit).

• Gently sand the underside of the heavier blade near the tip.

• Test after each small sanding to avoid overdoing it.

Important: Sand symmetrically and avoid thinning the blade too much.

2. Trimming

Best for: coarse adjustments or severely unbalanced props

• Carefully use a blade or scissors to trim excess flashing or material from the edge of the heavier blade.

• Only attempt this if you're confident—trimming can affect blade aerodynamics.

• Re-test frequently during the process.

Tips for Safe and Effective Balancing

• Balance both clockwise (CW) and counterclockwise (CCW) propellers separately.

• Always work in a well-lit area and wear protective eyewear when sanding or trimming.

• Don’t overcorrect. It’s better to make small changes and retest often.

• Avoid using water-based adhesives—they may loosen in flight due to temperature or humidity.

• Check balance again after any hard landing or crash.
  
  

Tape:
Using tape is one of the most accessible and widely used methods to add weight to a lighter propeller blade. Electrical tape, masking tape, or clear scotch tape are all viable options.

Advantages:

• Easy to apply and remove

• Adjustable in size and position

• Ideal for quick, temporary balancing

How to use:

• Cut a small strip and apply it near the tip or on the underside of the lighter blade.

• Press firmly to ensure it adheres well and doesn’t shift during flight.

• If needed, layer multiple pieces to fine-tune the balance.

Caution: Use only as much as necessary. Excessive tape can peel off mid-flight or create drag.

Screws and Washers

For larger drones or heavy-duty applications, adding tiny screws or metal washers to the propeller hub or root (if design allows) is a more permanent and precise balancing method.

Advantages:

• Highly accurate weight addition

• Secure and stable under high RPMs

• Ideal for professional or industrial drones

Application tips:

• Only use this method if the propeller structure allows mechanical attachments.

• Ensure added components are secured with thread-locking adhesive or locking nuts.

• Re-check dynamic balance after installation.

2. Techniques for Removing Material

When a blade is too heavy, you’ll need to remove small amounts of material until balance is achieved. Always proceed cautiously to avoid weakening the structure.

Sanding

Sanding is the most controlled method for removing material. It allows for gradual, localized adjustments.

Best tools:

• Fine-grit sandpaper (400–800 grit)

• Diamond file for carbon fiber props

• Nail file for lightweight plastic blades

How to sand:

• Identify the heavier blade (based on balancer reading).

• Lightly sand the underside or leading edge of the heavier blade, ideally near the tip.

• Test on the balancer after each pass to monitor changes.

Warning: Sanding too aggressively can alter the propeller's aerodynamic profile or structural integrity.

Trimming

Trimming is a more aggressive method used for props that are significantly out of balance or have excess flash or molding errors from manufacturing.

How to trim:

• Use precision scissors or a craft knife.

• Remove micro amounts from the trailing edge or tip of the blade.

• Only trim in straight, symmetrical lines—never shave curves or structural areas.

Note: Trimming should be a last resort or used when replacing the propeller isn't feasible.

3. Key Considerations

When balancing drone propellers, always keep the following factors in mind:

Material Type

Plastic props are easier to modify but may wear quickly.

Carbon fiber props are durable but harder to sand and should be handled with caution.

Blade Symmetry

Ensure that any changes made do not alter the aerodynamic balance between blades in terms of shape, thickness, or airfoil profile.

Dynamic vs Static Balance

Static balance ensures the prop remains level when not spinning.

Dynamic balance addresses issues while the propeller is rotating. For high-performance applications, dynamic balancing is ideal, though it may require specialized equipment.

Environmental Factors

Dust, moisture, or damage from hard landings can alter a previously balanced propeller. Always recheck after extended use or visible impact.

4. Next Steps

Once your propellers are properly balanced:

• Label or color-mark them to distinguish balanced props from unbalanced spares.

• Perform a hover test: Observe if the drone vibrates or drifts without control input.

• Rebalance periodically, especially if you fly in harsh conditions or switch to new propellers.

• Consider upgrading to precision-made props or using a digital prop balancer for repeatable results.

5. Key Considerations When Adjusting Propeller Balance

While both adding and removing mass can help fine-tune propeller balance, each method comes with trade-offs. Understanding these nuances is key to achieving optimal performance and maintaining safety.

One major benefit of removing material is that it avoids introducing foreign substances or parts to the drone's flight system. No adhesives, fasteners, or compounds are left behind, which helps keep the propeller lightweight and streamlined.

However, this approach can come at a cost: altering the structure of a blade, even slightly, may reduce its mechanical strength or aerodynamic efficiency. Sanding too aggressively or trimming too much from the tip can lower the maximum safe RPM, reduce lift, or introduce unwanted vibration.

Targeting the Right Areas

Precision is crucial. When sanding, focus on the bottom (non-lifting side) of the blade to protect the airfoil shape and preserve airflow integrity. For trimming, always remove material from the trailing edge or blade tips, not the leading edge, to maintain consistent thrust and aerodynamic balance.

Safety Precautions

Balancing propellers—especially when using powered balancing tools—requires strict attention to safety:

• Clear your workspace of debris that could be pulled into spinning propellers.

• Wear protective eyewear and gloves during adjustments.

• Keep your body and hands away from blades in motion.

Always assume the worst-case scenario—plan with Murphy’s Law in mind.

A small oversight during balancing can lead to damage, injury, or even full system failure during flight. Always prioritize safety over speed.

6. Next Steps and Further Learning

We hope this guide has helped you better understand the practical methods for adjusting drone propeller balance through both material addition and removal. These techniques, when applied correctly, can significantly enhance flight stability, extend component life, and improve efficiency.

Are there other balancing techniques you’ve used successfully? We welcome input from the drone community—share your ideas and we’ll explore them in future articles.

Looking to dive deeper? You might be interested in:

• [How to Reduce Drone Noise From Propellers]

• [Common Signs of Unbalanced Propellers and How to Fix Them]

• [Propeller Balancing Standards and Tolerances]

If you're ready to start balancing your own drone propellers, consider exploring dynamic balancing tools for greater precision and repeatability.