How To Fix a Table Saw That Makes a Humming Noise But Won’t Start?

Why does my table saw motor hum and not start

The reason for a table saw to produce a humming noise without starting  is because of a start capacitor problem, centrifugal switch problems, and broken or loose winding wires.

 

 

Start Capacitor problem

Most table saws feature a single-phase motor. This is irrespective of whether the model is direct drive or belt-driven. Capacitors are needed to jump-start the rotation motion in the rotor of these motors. This is why it tends to start working if you give your saw a spin while humming.

However, when these capacitors lose their charge, they lose the capacity to give these motors a head-start. Fixing it is easy because the capacitor is usually placed outside the motor.

 

Centrifugal switch problem

There are two primary windings of wires in your table saw’s motor: the start and run windings. As the name implies, the start winding is only required for a short period.

There is a need to discontinue the circuit of the start windings after your rotor comes to life. The Centrifugal mechanism is the ingenious solution to disengaging this circuit when the motor has started.

However, it is a quite delicate system, which can get spoilt from:

• Saw dust filling up the mechanism and causing it to be stuck
• A loss of alignment after continuous use.

If this problem persists and you continue to use the table saw without fixing it. You run the risk of heating up your motor. This could permanently damage the motor of your table saw.

 

Broken or loose winding wire

The wires inside the motor are responsible for generating the electromagnetic field. This is channeled into producing the torque that provides your table saw with its rotation.

However, the saw might stop working when these wires become broken or loose. It is usually caused by the overheating of the motor. This overheating is a common issue with the direct-driven table saw motors like the Craftsman 10″ table saw and the Ryobi portable table saw.

 

How to fix a table saw motor that hums and won’t start?

To fix a table saw that has a motor that hums and won’t start you will need to fix the start capacitor, centrifugal switch issues, and broken winding wires. Follow the following step-by-step guidelines to fix the problems.

Start Capacitor problem

Follow this step-by-step guide to fix your table saw’s start capacitor:

1. For safety measures, make sure your tool is disconnected from the power source
2. Look out for a small cylindrical object (about 2 to 3 inches in length) fixed to the body of your motor. This is your start capacitor.
3. Unscrew the capacitor using a Phillips screwdriver.
4. Use caution when working with capacitors. They can store a significant amount of charge even after being disconnected from power. Allow your machine to sit for 2 hours.
5. Short the capacitor by putting a screwdriver across both terminals of the capacitor simultaneously to ensure there is no voltage left.
6. If you have a multimeter, set it to Ohms reading. Then, test the capacitor with it. You should get a positive deflection on an analog multimeter or an infinite reading on a digital one.
7. If you are not getting any reading, the capacitor is spoiled and needs to be replaced.
8. Uncouple and remove the capacitor.
9. Write down the details on the capacitor: the microfarad values and the voltage.
10. Use these details to order a replacement capacitor at reputable stores like Amazon.com.
11. The replacement capacitor must have the same microfarad values as the original one. The voltage must also be the same or higher.
12. Couple the new capacitor
13. Secure it back onto the body of the motor using the screws.
14. Your table saw should now start appropriately without the humming noise.
15. Enjoy your newly rejuvenated table saw.

 

Centrifugal switch problem

To fix your table saw’s centrifugal switch problem, follow this detailed guide:

1. For your safety, you must ensure your saw is disconnected from the power source
2. The centrifugal switch is inside the rear cover of the motor. This is where the fan is usually located in some models.
3. Remove the fan cover from the end of the motor
4. Loose the retaining screw and remove the fan from the retaining shaft
5. If your motor has a dust cover, remove it
6. Unscrew the switch from the shaft and slide it off the shaft
7. Locate the point on the contact plate and make sure these are in an open position.
8. If they are in a closed position, bend the circular ring back until they don’t contact one another.
9. You must replace the contact plate if they are welded shut together.
10. If pittings are on the contact plate, use 400 grit sandpaper to smoothen it gently.
11. If there are larger deformities on the contact plates, you must replace them.
12. Ensure the spring tension is enough to make them come together and separate correctly.
13. Check the centrifugal mechanism on the motor shaft. It should have two weights, cams, and a spring-loaded to swing close to the shaft when it is not spinning. This mechanism moves a plastic collar on the shaft.
14. This area tends to get dirty or rusty. Clean the collar and this area using a strip of fine cloth.
15. Rotate the motor shaft to ensure you get every side of the collar.
16. Wipe the shaft area with thin machine oil.
17. Use compressed air to blow out and clean the inside of the motor to remove all the dirt and sawdust.
18. Re-assemble the motor.
19. Plug it in and start and stop the machine before installing it back to your saw.
20. Enjoy your favorite DIY woodwork projects on your newly rejuvenated saw.

 

Broken or loose winding wire

If all the fixes discussed above don’t work, you need to take your motor to a repair shop. The engineer will check if the winding wire in your motor is broken. He could then rewire the motor, and you will save money on buying a replacement motor.

A damaged motor

Suppose all the above steps failed. Then you are left with no choice but to buy a replacement motor.

1. Ensure the model number of the replacement motor corresponds to that of the damaged one.
2. Only buy from reputable online stores.
3. Before installing the new motor, disconnect your saw from the power source.
4. Disconnect the switch from the body of the table
5. Remove the 3 screws used to secure the motor
6. Ensure the new motor is properly secured without damaging the screws.
7. Reconnect your switch to the new motor and fasten it to the side of your table saw
8. Enjoy the power of your new cutting tool.

 

Why is my table saw making a grinding noise?

Your table saw is making a grinding noise because of damaged arbor bearings or loose pulley. The pulley problem is relatively easy to fix. However, the bearings require careful attention to detail and a little bit of improvisation.

Pulley Problem

Follow this step-by-step guide to fix the pulley and belt issues:

1. Disconnect the belt from the pulley
2. Loosen the nut that holds the pulley on.
3. Remove the pulley from the shaft
4. Examine if they are bent or crushed.
5. If so, you need to get a replacement. They cost about $5 a piece on Amazon.
6. If it is intact, clean it out, tighten it back onto the motor

 

Arbor Bearings Problem

Both bearings on the arbor could get damaged. Therefore, the repair is best done with professional tools like a bearing puller and a wrench. However, as a DIY enthusiast, I am sure you are used to improvising.

1. For safety measures, disconnect your saw from the power source.
2. Remove the table saw’s top by unscrewing the screws in the four corners.
3. Carefully lift off the top and set it aside in a safe place
4. Loosen the nut that holds the pulley on
5. Slide the pulley off, remove the key and keep it in a safe location
6. Remove the bushing on the shaft and set it aside
7. Remove the screw that holds the bearing in place
8. Using a mallet and a wood spacer, gently tap the arbor out of the trunnion
9. Remove the second bearing, and use the sleeve on the arbor to tap it out
10. Use a parallel clamp to press the new bearing into place
11. Turn the arbor upside down, hold it down with a wrench on a table
12. Use a mallet to hit the arbor until the bearing comes off
13. Install the new bearing using a socket or wooden space to drive the bearing into place.
14. Reseat the arbor into the trunnion by using the mallet
15. Insert the bushing, key, and pulley back into place
16. Tighten the nut that holds the pulley into place
17. Return the top of the table saw, securing it with the four screws you removed earlier

 

Why is my table saw making a strange noise?

The two strange noises common to table saws are humming and grinding sounds. The humming sound is commonly followed by difficulty the miter saw on.

The first noise is caused by either a start capacitor problem, centrifugal switch problem, or broken or loose winding wires. To fix this problem, follow the guidelines above on troubleshooting a humming noise in your saw.

The second noise is caused by damaged arbor bearings or loose pulley. You should start by tightening the pulley. If that doesn’t work, go ahead to change the arbor bearings. Follow the detailed guidelines highlighted above.

 

How to fix a Craftsman table saw that hums and won’t start?

The reason your Craftsman table saw hums and won’t start is because of faulty start capacitors, centrifugal switch issues, and broken winding wires.

To fix this problem, follow the guidelines above on troubleshooting a humming noise in your Craftsman table saw. This will involve:

1. Checking if your capacitor still has a charge
2. Buying and installing an appropriate replacement capacitor
3. Cleaning out the centrifugal switch mechanism
4. Take your Craftsman table saw’s motor to a repair shop for rewriting
5. Buying a replacement motor if all the above steps fail

 

Why is my Ryobi table saw making a noise?

Several reasons could cause a troubling noise in your Ryobi table saw; the most common ones are a start capacitor problem and a centrifugal switch problem.

Other possible reasons are:

• broken or loose winding wires
• damaged arbor bearings
• loose pulley

To fix this problem, follow the guidelines above on troubleshooting the noise in your Ryobi table saw. This will involve:

1. Checking if your capacitor still has a charge
2. Buying and installing an appropriate replacement capacitor
3. Cleaning out the centrifugal switch mechanism
4. Checking the tightness of your pulley
5. Make sure you don’t have a spoilt belt
6. Changing the arbor bearing if they are damaged
7. Take your Ryobi table saw’s motor to a repair shop for rewriting
8. Buying a replacement motor if all the above steps fail

 

Why is my Bosch table saw making a noise?

The reason why your Bosch table saws make noise is a spoilt bearing. Some users notice this noise barely 6 months into using their tool.

Other possible causes are:

• A loose pulley
• A loose blade
• Dirty centrifugal switch

To fix this noise, follow these steps:

1. Unplug your saw
2. Try to spin the blade slowly by hand
3. If it feels notchy, it is most likely a spoilt bearing. Follow the guideline above on how to change your table saw’s bearing.
4. If it doesn’t, look towards the other causes like tightening your pulley
5. Retighten your blade if it feels loose
6. If the noise occurs while your Bosch table saw doesn’t come on, follow the guideline on troubleshooting humming noises.

 

Why is my Ridgid table saw making a noise?

The noise from a Ridgid table saw is commonly due to oxidized brushes and armature or a bad bearing. To fix this, follow this step-by-step guide.

1. Unplug your saw
2. Try to give it a spin by hand
3. If it feels notchy, it is most likely a spoilt bearing. Follow the guideline above on how to change your table saw’s bearing.
4. If it doesn’t, you need to buy a replacement brush
5. To install the new one, open the motor cover by unscrewing the 3 screws holding it in place
6. Remove the brush through the brush holder
7. Install the new brush
8. Secure the motor cover with the screws

 

Why is my Delta table saw making a noise?

The two commonest noise causes in a Delta table saw are a loose pulley and a bad arbor bearing. Follow these steps to remove the noise:

1. Unplug your saw
2. Loosen the nut that holds the pulley on.
3. Remove the pulley from the shaft
4. Examine if it is bent or crushed.
5. If so, you need to get a replacement. For example, the pulleys on the Delta table saw cost about $5 a piece on Amazon.
6. If it is intact, clean it out, tighten it back onto the motor
7. If the noise persists, follow the abovementioned steps to change your arbor bearings.