Orbital Sander Slows Down — Top Causes and Surefire Fixes

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An orbital sander is a valuable tool in any woodworker’s arsenal, providing efficient sanding and smoothing capabilities. However, like any power tool, orbital sanders can experience issues that cause them to lose speed or operate at a slower pace than expected. 

In this comprehensive guide, we’ll delve into the factors that can lead to decreased speed and offer troubleshooting tips to help you address these problems effectively. 

What Causes an Orbital Sander to Lose Speed?

Frayed or Torn Power Cords

One common cause of a slowdown in an orbital sander is frayed or torn power cords. Power cords can become damaged for several reasons, including improper handling, constant bending, or accidental tugs. 

orbital sander and power cord

It can result in a compromised electrical connection, leading to decreased speed or the sander not working.

What Causes Power Cords to Become Frayed or Torn?

Several factors contribute to frayed or torn power cords. These include:

1. Excessive Bending

Repeatedly bending the power cord at sharp angles can cause the wires inside to fray or break, resulting in poor electrical conductivity.

2. Pulling or Tugging

Yanking the power cord forcefully or accidentally tripping over it can lead to damage, including fraying or tearing.

3. Pinching

Pinching the power cord between heavy objects or closing doors can cause the insulation to wear down and expose the internal wires.

inspecting sander cord

4. Age and Wear

Over time, power cords can deteriorate naturally due to wear and tear, making them more susceptible to fraying or tearing.

What Are the Ways to Repair Torn Power Cords?

If you notice a torn power cord on your orbital sander, it is crucial to address the issue promptly to prevent further damage and ensure your safety. Here are some steps to repair torn power cords:

1. Disconnect the Sander

Unplug the sander from the power source to avoid electric shock before attempting any repairs.

2. Examine the Damage

Assess the extent of the tear or damage to determine whether the cord can be repaired or needs replacement.

3. Electrical Tape Repair

Electrical tape can temporarily fix minor tears or frays. Wrap the tape tightly around the damaged area, covering all exposed wires.

using electrical tape

4. Wire Splice and Replacement

If the tear is severe or extends into the internal wires, replacing the damaged portion of the power cord is best. Cut out the damaged section, strip the insulation from the wires, and use wire connectors to join the new cord segment to the existing cables. Ensure proper insulation and secure the connection with electrical tape.

5. Professional Repair or Replacement

If you need clarification on handling electrical repairs or if the damage is extensive, it is advisable to seek professional assistance or consider replacing the entire power cord.

Dust and Debris Buildup Lead to Clogging

Another factor that can cause an orbital sander to lose speed is the buildup of dust and debris. Over time, the accumulation of sanding dust, resin, or other materials can clog the sander’s internal components, impeding its movement and reducing efficiency.

What Causes Dust and Rust to Clog?

Dust and rust can accumulate in an orbital sander due to various factors:

1. Sanding Dust

As you use the sander, fine dust particles from the sanding process can accumulate inside the sander’s housing and around the motor.

inspect dust collector

2. Resin Buildup

When sanding resinous materials such as certain types of wood or adhesives, the resin can accumulate on the sandpaper and within the sander, causing clogging.

3. Moisture and Humidity

Exposure to moisture or high humidity levels can cause dust particles to clump together or create a damp environment where rust can form on the sander’s components.

What Are the Methods to Resolve the Issue of Dust and Rust Clogging?

To resolve the dust and rust clogging issue, you should know it is crucial to implement proper cleaning and maintenance practices. Here are some methods to consider:

1. Regular Cleaning

After each use, take the time to clean your orbital sander thoroughly. Use a soft brush or compressed air to remove dust and debris from the housing, sandpaper, and vents. Wear appropriate personal protective equipment (PPE) when performing this task.

2. Sandpaper Replacement

If you notice significant resin buildup on the sandpaper, replace it with a fresh one. It will ensure optimal sanding performance and prevent clogging.

sanding discs

3. Internal Cleaning

Periodically disassemble the sander and clean the internal components. Use a soft brush, compressed air, or a vacuum cleaner to remove accumulated dust or debris. Take care not to damage any delicate parts during the cleaning process.

4. Rust Prevention

Store your sander in a dry and well-ventilated area to prevent rust formation. Consider using moisture-absorbing packets or placing the sander in a sealed container with a desiccant to control humidity levels.

Faulty or Worn-out Bearings

The bearings in an orbital sander play a crucial role in its operation, ensuring smooth rotation and movement of the sanding pad. When the bearings become faulty or worn out, it can cause the sander to lose speed, produce vibrations, or generate excessive noise.

What Causes Bearings to Become Damaged?

Several factors can contribute to bearing damage in an orbital sander:

1. Lack of Lubrication

Insufficient lubrication can cause increased friction and heat buildup, leading to premature bearing failure.

orbital sander repair

2. Contamination

Dust, debris, or foreign particles entering the bearing housing can cause damage, resulting in reduced speed or complete failure.

3. Wear and Tear

Over time, the constant use of the sander can cause natural wear and tear on the bearings, affecting their performance.

Ways to Repair Damaged Bearings

If you suspect that the bearings in your orbital sander are damaged or worn out, it is essential to address the issue promptly to restore the sander’s optimal performance. Here are some steps to repair or replace damaged bearings:

1. Bearing Inspection

Begin by disassembling the sander and carefully inspecting the bearings for any signs of damage or wear. 

Look for rust, pitting, or excessive play in the bearings. Bearings in good condition should feel smooth when rotated and have no noticeable damage. 

bearing inspection

If you observe any significant issues with the bearings, proceeding with repairs or replacements may be necessary.

2. Cleaning

If the bearings show signs of contamination or dust buildup, it is important to clean them thoroughly. Use an appropriate solvent or bearing cleaner recommended by the manufacturer to remove debris or contaminants. 

Follow the manufacturer’s instructions for cleaning, and use a soft brush or cloth to remove any residue gently. Cleaning the bearings will help ensure smooth and efficient operation.

3. Lubrication

Once the bearings are clean and dry, applying a suitable lubricant recommended by the manufacturer is crucial. Lubrication helps reduce friction and wear, allowing the bearings to rotate smoothly. 

lubricating orbital sander parts

Apply a small amount of lubricant to the bearings, taking care not to over-grease. Excess lubricant can lead to leakage or interfere with other components of the sander. Refer to the manufacturer’s instructions for the appropriate type and amount of oil.

4. Replacement

If the bearings are severely damaged or worn out, it may be necessary to replace them. Consult the sander’s user manual or contact the manufacturer for information on compatible bearing replacements. Using the correct bearings to ensure proper fit and functionality is crucial. 

Follow the manufacturer’s instructions for bearing replacement, including any specific alignment or installation procedures. Proper installation will help prevent further issues and ensure the smooth operation of the sander.

Following these steps, you can effectively repair or replace damaged bearings in your orbital sander. Regular inspection, cleaning, and lubrication will help prolong the life of the bearings and ensure the sander operates at its best. 

assembling orbital sander

However, if you are unsure or uncomfortable with performing these repairs yourself, it is recommended to seek professional assistance or consult the manufacturer for further guidance. They can provide specific instructions and recommendations tailored to your sander model.

Inadequate Power Supply

An inadequate power supply can significantly impact the speed and performance of an orbital sander. Ensuring that the sander is receiving sufficient power to operate at its optimal level is crucial. 

Several factors can contribute to an inadequate power supply, including low voltage, faulty power outlets, or an extension cord that cannot deliver the required current.

What Causes Problems with Power Supply?

There are several causes for inadequate power supply to an orbital sander:

1. Low Voltage

Low voltage is a common issue that can cause an orbital sander to operate slowly. If the voltage supplied to the sander exceeds the recommended range, the motor may not receive enough power to perform at its full potential. 

testing orbital sander

To address this issue, ensure that the power outlet you use provides the correct voltage specified by the manufacturer for your sander model.

2. Faulty Power Outlets

Another potential cause of inadequate power supply is faulty power outlets. Over time, power outlets can become worn out or damaged, leading to inconsistent power delivery. 

It can negatively impact the performance of your orbital sander. If you suspect your power outlet is faulty, consider testing the outlet with other electrical devices to confirm the issue.

3. Incompatible Extension Cords

Using an extension cord that cannot deliver the required current can also result in an inadequate power supply to the orbital sander. 

checking sander power cord

Extension cords with a lower gauge (thicker wires) can carry more current, while those with a higher gauge (thinner wires) may restrict the flow of electricity. 

Solutions for Power Supply Problems

To address power supply problems and ensure the optimal performance of your orbital sander, consider the following solutions:

1. Voltage Check

Verify that your power outlet provides the correct voltage for your orbital sander. Use a voltage tester or consult an electrician to ensure the outlet meets the sander’s requirements.

2. Stable Power Outlets

If your power outlets are faulty or have an unstable connection, consider repairing or replacing them. It is essential to have a reliable power source for consistent and efficient operation.

3. Suitable Extension Cords

If you need an extension cord, ensure it is ideal for power tools and can deliver the required current without a significant voltage drop. Use an extension cord with an adequate wire gauge [1] to handle the power demands of your orbital sander.

Malfunctioning Motor

A malfunctioning motor can be a significant culprit behind an orbital sander losing speed. The engine is responsible for powering the sanding pad’s rotation, and any damage or issues with the motor can affect its speed and overall performance.

testing orbital sander

What Causes Damage to the Motor of an Orbital Sander?

Several factors can cause damage to the motor of an orbital sander:

1. Overheating

Continuous or prolonged use of the sander without allowing the motor to cool down can lead to overheating, causing damage to the motor windings and internal components.

2. Dust and Debris Accumulation

Excessive dust and debris entering the motor housing can hinder the motor’s operation, leading to decreased speed and performance.

3. Lack of Maintenance

Neglecting regular cleaning and maintenance of the motor can accumulate dirt, dust, and debris, affecting its efficiency and causing damage over time.

Ways to Repair an Orbital Sander Motor

If you suspect that the motor of your orbital sander is malfunctioning, it is important to address the issue promptly. Here are some steps to repair a malfunctioning engine:

orbital sander motor repair

1. Cooling Period

Let the motor cool down completely before repairing or troubleshooting if it feels hot.

2. Cleaning

Thoroughly clean the motor housing and internal components to remove dust, debris, or obstructions. Use a soft brush, compressed air, or a vacuum cleaner to clean the motor, taking care not to damage any delicate parts.

3. Lubrication

Apply a small amount of lubricant to the motor’s moving parts per the manufacturer’s recommendations. It will ensure smooth operation and reduce friction.

4. Professional Assistance

If the motor issues persist or you are not confident handling motor repairs, it is advisable to seek professional assistance or consult the manufacturer for guidance. They may recommend replacing the motor or provide further troubleshooting steps.

Damaged Rotor

The rotor is a crucial component in an orbital sander that is vital to the tool’s operation. Damage to the rotor can occur due to excessive heat buildup, improper use, or wear and tear over time. A damaged rotor can lead to a decrease in speed and hinder the sander’s overall performance.

orbital sander rotor

What Causes Damage to the Rotor of an Orbital Sander?

Several factors can cause damage to the rotor of an orbital sander:

1. Overheating

Operating the sander continuously without cooling it down can cause excessive heat buildup, potentially damaging the rotor.

2. Improper Use

Applying excessive pressure, using the sander on unsuitable materials, or subjecting it to harsh conditions can damage the rotor.

3. Wear and Tear

As with any mechanical component, the rotor can experience wear and tear over time, leading to reduced performance.

Methods to Repair Damaged Rotor

If you suspect that the rotor of your orbital sander is damaged, consider the following repair methods:
orbital sander repair

1. Cooling Period

Allow the sander to cool down completely if it feels hot to the touch. Operating the sander with a damaged rotor can exacerbate and cause further damage.

2. Cleaning

Clean the rotor and the surrounding components to remove any debris or obstructions. Use a soft brush or compressed air to dislodge any dirt or dust that may affect the rotor’s performance.

3. Rotor Replacement

If the rotor is severely damaged or worn out, it may need to be replaced. Consult the sander’s user manual or contact the manufacturer for information on compatible rotor replacements. Follow the manufacturer’s instructions for proper installation and alignment.

Corrosion on the Shaft

Corrosion on the shaft of an orbital sander can result from exposure to moisture, humidity, or improper storage conditions. Rusting of the shaft can cause the sanding pad to rotate less smoothly, decreasing speed and overall performance.

orbital sander shaft inspection

What Causes Rusting of a Shaft?

Rusting of the shaft can occur due to various factors:

1. Moisture and Humidity

Exposure to moisture, high humidity levels, or inadequate drying after cleaning can lead to rust formation on the shaft.

2. Improper Storage

Storing the sander in damp or humid environments can increase the likelihood of shaft corrosion over time.

Solutions for a Rusted Shaft

To address a rusted shaft and restore optimal performance to your orbital sander, consider the following solutions:

1. Shaft Inspection

Inspect the shaft for rust or corrosion. If the rust is minor and hasn’t affected the shaft’s integrity, you may be able to remove it with proper cleaning and treatment.

orbital sander disassembly

2. Cleaning

Use a mild abrasive pad or fine-grit sandpaper to gently remove the rust from the shaft. Be careful not to damage the surface or remove any protective coatings.

3. Rust Prevention

After cleaning, apply a rust inhibitor or protective coating to the shaft to prevent future corrosion. It can help prolong the lifespan of the shaft and ensure smooth operation.

Incorrect Assembly

Improper assembly of an orbital sander can also cause a decrease in speed. If components are not aligned correctly or screws are not tightened appropriately, it can lead to friction and hinder the smooth movement of the sanding pad.

How Does Incorrect Assembly Cause Slowdown in an Orbital Sander?

Incorrect assembly of an orbital sander can lead to several issues that affect its speed:

1. Misalignment

If the components of the sander, such as the sanding pad, bearing, or motor, are not aligned correctly during assembly, it can create friction and impede the sanding pad’s movement.

orbital sander assembly

2. Loose Screws or Fasteners

If screws or fasteners are not tightened adequately, it can result in wobbling or instability of the sanding pad, causing a decrease in speed and efficiency.

How Do You Repair an Orbital Sander that has been Improperly Assembled?

If your orbital sander has been improperly assembled, it is crucial to address the issue to restore its functionality. Here is a detailed breakdown of the steps to repair an orbital sander that has been improperly assembled:

1. Disassembly

Begin by carefully disassembling the sander, paying close attention to the orientation and arrangement of the components. Take note of the sequence in which the parts were assembled, as this will be helpful during reassembly. 

It is recommended to refer to the sander’s user manual or consult the manufacturer’s instructions for disassembly guidance specific to your model.

2. Alignment

Once the sander is disassembled, inspect the components and ensure they are aligned correctly. Check the sanding pad, bearings, motor, and other relevant parts to ensure proper alignment. Consult the sander’s user manual or the manufacturer’s instructions for appropriate alignment procedures.

sanding cutting board

3. Tightening Screws or Fasteners

After confirming the proper alignment, carefully check all screws and fasteners. Ensure that they are drawn appropriately to secure the components in place. Use a screwdriver or wrench, as required, to tighten the screws. 

However, be cautious not to overtighten, as this can damage the components or hinder their smooth movement. Follow the recommended torque specifications provided by the manufacturer.

4. Functionality Test

Once you have reassembled the sander and tightened all the necessary screws and fasteners, it is time to conduct a functionality test. 

Plug in the sander and turn it on. Check for smooth operation, proper rotation of the sanding pad, and consistent speed. If the sander operates smoothly without any unusual noises or vibrations, it indicates a successful repair. 

However, if any issues persist, such as speed variations or abnormal behavior, it may be necessary to double-check the assembly and consult the manufacturer or seek professional assistance for further troubleshooting and repair.

testing orbital sander

By following these steps, you can effectively repair an orbital sander that has been improperly assembled. 

Proper alignment and secure fastening of the components are crucial to ensure optimal performance and prevent speed loss or other issues during sanding operations. 

Remember to refer to the sander’s user manual or manufacturer’s instructions for specific guidance, as different models may have unique assembly requirements.

Tips for Troubleshooting an Orbital Sander

In addition to addressing specific issues that can cause an orbital sander to lose speed, there are several general tips for troubleshooting common problems. 

using orbital sander on epoxy resin

By following these tips, you can maintain the optimal performance of your sander and identify potential issues early on. Here are some valuable tips for troubleshooting your orbital sander:

1. Lubrication

Regularly lubricate your orbital sander’s moving parts and bearings with the appropriate lubricants recommended by the manufacturer. Lubrication helps reduce friction, improve the sander’s performance, and extend lifespan. 

Follow the manufacturer’s instructions for lubrication intervals and the specific lubricant. Proper lubrication ensures smooth operation and prevents unnecessary wear and tear.

2. Proper Cleaning and Maintenance

Following the manufacturer’s guidelines for cleaning and maintaining your orbital sander. Regular cleaning removes dust, debris, and resin buildup, which can affect the sander’s performance and speed. 

Use a soft brush or compressed air to remove particles from hard-to-reach areas. Pay attention to the ventilation ports, motor housing, and sanding pad. 

clean orbital sander

Additionally, inspect the power cord for any signs of damage or wear and replace it if necessary. Keeping your sander clean and well-maintained can prevent potential issues and ensure longevity.

3. Use Correct Sandpaper Grit

Choosing the appropriate sandpaper grit for your project is crucial. Using the wrong grit can put unnecessary strain on the sander and result in speed issues. 

Refer to the manufacturer’s recommendations or consult sanding guides to determine the right grit for the material you are working on. 

Starting with a lower grit for rough sanding and gradually progressing to higher grits for finer finishes will help maintain optimal performance and achieve the desired results.

4. Avoid Excessive Pressure

When using an orbital sander, applying even, moderate pressure is important. Excessive pressure can overload the motor, cause premature wear of the sanding pad, and decrease speed. 

operating a blue orbital sander

Let the sander do the work and allow the sanding grit to contact the surface naturally. Excessive pressure affects the speed and can result in uneven sanding and damage to the material. 

Using the right pressure ensures consistent and efficient sanding while protecting the sander’s components.


Should an orbital sander be fast or slow?

The speed of an orbital sander depends on the material being sanded and the desired result. Generally, starting with a lower rate and gradually increasing as needed is recommended. Higher speeds suit rough grinding or material removal, while lower speeds are better for finer finishes.

What causes an orbital sander to stop when pressure is applied?

An orbital sander may stop when excessive pressure is applied because it activates a safety feature to prevent motor or sanding pad damage. This feature helps protect the sander and ensures the sanding process remains controlled.

What is the effect of applying excessive pressure on a sander?

Applying excessive pressure on a sander can cause several issues, including decreased speed, strain on the motor, premature wear of sandpaper, and an uneven sanding result. It is important to apply moderate, even pressure for optimal performance and to maintain the longevity of the sander.

What is the recommended speed for operating an orbital sander?

The recommended speed for operating an orbital sander depends on the specific model and the task. Refer to the manufacturer’s guidelines and adjust the rate for the material and desired finish. 

Starting at a lower speed and gradually increasing until the desired results are achieved is always advisable.

What causes an orbital sander to operate at a slow speed?

An orbital sander operating at a slow speed can be caused by various factors discussed in this article, including frayed power cords, dust and debris clogging, faulty bearings, inadequate power supply, motor malfunction, or damaged rotor. 

Identifying and addressing the cause will help restore the sander’s speed and performance.


Understanding why an orbital sander is losing speed is essential for troubleshooting and maintaining its optimal performance. 

By addressing issues such as frayed power cords, dust and debris buildup, faulty bearings, inadequate power supply, motor malfunctions, damaged rotor, corrosion, and incorrect assembly, you can resolve slowdown problems and ensure smooth sanding operations. 

Robert Johnson is a woodworker who takes joy in sharing his passion for creating to the rest of the world. His brainchild, Sawinery, allowed him to do so as well as connect with other craftsmen. He has since built an enviable workshop for himself and an equally impressive online accomplishment: an extensive resource site serving old timers and novices alike.
Robert Johnson
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