Planer: Motor Gets Hot

A bearing is a device that is used to enable rotational, or linear, movement and reduces friction and handles stress. Over time, bearings wear out and produce a growling, grinding or a humming noise and will be accompanied by a vibration. These repair procedures will vary from model to model.
To check the armature bearings, remove the sides, gear box cover and remove the retaining clips holding the sprockets and chain on. Take off the bolts securing the motor housing to the planer. Remove the bolt on the belt tensioning bracket to release the tension and remove the belt.
For models without a belt tension, removing the belt can be tricky. You may have to gently pry it off with a screwdriver as you walk it off the pulleys. Make sure you only place the tip of the screwdriver on the pulleys, not for leverage but to avoid damaging other parts. Remove any power cable hold-downs. Lift the motor and detach any ground wires under it and place the motor assembly on a bench. Remove the brush caps and brushes, followed by the switch from the housing. Take a photo of the wire attachments before disconnecting them, for easier reassembly.
Separate the switch housing from the motor housing and feed the wires out of it. Remove the screws on the back cover of the motor, followed the retaining ring behind the pulley, on the other side of the motor. Now, tap the pulley with a rubber mallet to separate the armature from the motor housing. Remove the back cover from the armature shaft, with the spring washer. Spin the bearings to determine which one is bad – they should spin freely, with no noise. A worn bearing will spin rough and make a noise.
To replace the bearing behind the pulley, you will have to remove the pulley. Pulleys attach in may different ways. Examine yours for a set screw, holding it in place (if there is no nut). If your model has neither a set screw or nut, then the pulley is pressed on and you will have to use a puller to remove it. You may want to heat it up a bit for easier removal. Use a bearing puller to remove the bearings. If clearances are tight, then use a separator to remove any bearings and only tap on the shaft with a mallet, or brass hammer, to avoid damaging the shaft.
Install new bearings onto the shaft using a socket that only makes contact with the bearings inner race to avoid any damage. Tap the socket with a hammer to seat the bearing in place. Now, reinstall the pulley. If the pulley was pressed on, heat the pulley up to expand it and then tap it in place. You may need to press it on, if this does not work.
Install the spring washer onto the armature shaft and the cover, then place the armature back into the motor housing. Tighten the cover down and reinstall the retaining ring behind the pulley on the opposite end of the motor. Feed the wires back into the switch housing and then reattach the wires to the switch (refer to your photo) and secure the switch into the housing. Reattach the ground wires and install the motor back onto the planer. Reinstall the power cord hold-downs, followed by the spacer onto the roller shaft. Place the sprockets inside the chain and position the sprockets back onto the shafts, aligning the keyways. The hubs on the sprockets must face the planer. Install on one feed roller, then the second for easier installation. Once positioned on the shafts, slide all of the way back. Reinstall the belt on the pulleys, adjust the tension and tighten the bolt. Reinstall the belt on the pulleys, adjust the tension and tighten the bolt.
For models without a belt tension, this can be a tricky procedure and will require patience. Carefully manoeuvre the belt through the clearances, possibly using a screwdriver, ensuring you do not cause any damage to the threads on the adjustment rod or the belt. When the belt is in position, start feeding it onto the smaller pulley first, then place the end of the screwdriver on the larger pulley nut. Only then can you gently pry the belt along the larger pulley. Once it is on the pulley a little bit, turn the pulley by hand at the same time you push on the belt, to walk it onto the pulleys. Reinstall the gear box cover and side covers.

The carbon brushes will wear down over time due to riding on the commutator, supplying electricity to the armature. When the carbon brushes wear out, they will produce more sparking, generate more heat and can cause the motor to get too hot. To examine the carbon brushes, remove the brush caps on either side of the motor and pull out the brushes. Brushes measuring less than 1/8 of an inch are worn and do need to be replaced immediately. Brushes that have uneven wear, chips, cracks or anything else out of the ordinary need to be replaced as well. Install new brushes into the housing and reinstall the brush caps.

The purpose of the fan is to keep the motor cool. It is located inside the motor, attached to the armature shaft. A broken fan will not be able to keep the motor cool, causing the motor to get hot. Repair procedures for the fan will vary between models, but will be similar. To inspect the fan, remove the side cover and the gear box cover. Remove the retaining clips, supporting the sprockets and chain in place and then remove both the sprockets and chain. Remove the support bolts for the motor housing and then the bolt on the belt tensioning bracket, followed by the belt.
For planers without a tensioner, removing the belt can be tricky; you may have to gently pry it off with a screwdriver as you walk it off the pulleys. Remove the power cord hold-downs. Lift the motor off the planer and detach any ground wires underneath. Place the motor on a bench and remove the brush caps and brushes, followed by the switch. Take a photo of the wire attachment, before removing them. Separate the switch housing from the motor housing and pull the wires out of it. Remove the screws securing the back cover of the motor and then remove the retaining ring behind the pulley on the other end of the motor. Tap on the pulley with a rubber mallet to free the armature from the motor housing. Remove the back cover from the armature shaft, with the spring washer. Take out the bearing with a bearing puller, or separator (if clearances are an issue), and then remove the retaining ring holding the fan on and slide the fan off of the shaft.
Install a new fan on the shaft and reinstall the retaining ring. Install the bearing back onto the shaft using a socket that only makes contact with the bearings inner race to avoid damage. Tap the bearing in place with a hammer. Install the spring washer and back cover and then install it back into the housing. Tighten the back cover. Install the retaining ring behind the pulley and then feed all the wires into the switch housing. Reattach the switch housing to the motor housing and connect the wires back to the switch (refer to your photo). Secure the switch to the housing. Reattach the ground wires under the motor on the planer and place the motor back onto the planner – tighten it down. Reinstall the power cord hold-downs and insert the sprockets inside the chain, positioning the sprockets back onto the shafts alighting the keyways. The hubs on the sprockets face the planner. Install on one feed roller, followed by the second, and then slide back on the shafts as a unit. This makes for easier installation.
Reinstall the belt – this can be difficult on models without a belt tensioner. Carefully manoeuvre the belt through the clearances, possibly using a screwdriver. Be very careful not to damage the threads on the adjustment rod or the belt. Once it is all of the way through, feed it onto the smaller pulley first and then place the end of the screwdriver on the larger pulley nut, gently prying the belt along the larger pulley. Once it is on the pulley a bit, you can walk it on the rest of the way by turning the pulley by hand and pushing on it. If your planer has a tensioner, then apply the correct amount of tension and tighten to hold in place. Reinstall the gear box cover and side covers.

In a lot of planers, bearings are seated inside the housing. If the housing becomes worn, the bearing can spin within the housing, causing the housing to heat up. If the housing is plastic, it can melt and produce a plastic burning smell. To replace the housing, remove the side covers and the gear box cover, followed by the retaining clips that holds the sprockets and chain on. Then, remove the sprockets and chain. Remove any spacers on the rollers and then the bolt on the belt tensioning bracket. Now, take the belt off of the pulleys. Not all planers have a tensioner; removing the belt can be very tricky and requires patience. You may have to gently pry it off with a screwdriver as you walk it off the pulleys. Remove the bolts securing the motor housing to the planer and then the cable hold-downs. Lift the motor up and detach the ground wires under the motor housing. Place the motor on a bench for easier disassembly. Remove the brush caps and brushes, followed by the switch from the switch housing. Take a photo of the wire attachments, for easier reassemble, and then disconnect the wires. Detach the switch housing from the motor housing and feed the wires out of it. Remove the screws on the back cover of the motor and then the retaining ring behind the pulley, on the other end of the motor. Tap on the pulley with a rubber mallet to free the armature from the motor housing. Take off the back cover and spring washer from the armature shaft. Remove the screws securing the field in place and then remove the field from the motor housing, transferring it into the new housing. Install the armature into the field. Make sure the spring washer is on the shaft and reinstall the motor cover. Reinstall the retaining ring on the opposite end and then reattach the switch housing to the motor housing. Feed all the wires through, reattaching them to the switch (reference your photo). Secure the switch back onto the housing and reassemble the cutter head back on to the planer, making sure to reattach the ground screw before placing the motor back on top of the planer. Secure the clamp the holds the power cord in place and install any spacers back onto the feed rollers. Insert the sprockets inside the chain and place the sprockets onto the shafts, aligning the keyways. When installing, make sure the hubs on the sprockets are facing the planner. Install onto one feed roller and then the second, for easier installation. Next, reinstall the belt back onto the pulleys and adjust the tension bracket and tighten the tension bolt to secure it in place. Belt installation on some models can be quite tricky and require some patience. You may have to manoeuvre the belt through some tight clearances by twisting the belt and using a screwdriver to feed it through, to get to the pulleys. Be careful not to damage the belt while getting it in place. Feed the belt on the smaller pulley first, then the larger one. This makes for easier belt installation. You will need to pry the belt over the larger pulley with a screwdriver to get it started. Make sure the end of the screwdriver is placed on the pulley nut for leverage – only so you do not cause any damage to the threads on the height adjusting rods. Once the belt is on, you can turn the pulleys by hand and walk it on the rest of the way. Reinstall the gear over and side panels.

The blades are located on the planer head, which rotates and shaves down the wood to the desired thickness. Over time, these blades will become dull and cause the motor to work harder in order for the dull blades to cut. The heat builds up in the planer head and transfers more heat to the motor. Check the sharpness of your blade. Unplug the planer and remove the hood to examine, or you can tip the machine on its side.
To replace the blades, remove the screws supporting the blade in place. Most planers come with a T-handle tool to remove the screws. This handle has two magnets inside the handle to lift the screws safely out of the planer. Keep pressure on the bar because it is spring loaded. Once all of the screws are removed, use the magnets in the handle to lift out the bar and the knife. Now, remove the springs. Clean out the inside of any debris so the new knives and bar will lay flat. Reinstall the springs and install the new knife. Some knives are double-sided so you can flip them around to the sharp side. Install the bar and make sure it is positioned on the nipples correctly. Insert the screws on the ends first, to stop the springs from getting loose. Tighten the screws hand tight in the beginning. Then, go around a second time and tighten with the tool. You will have to do this for each blade on the cutter head. Once completed, reinstall the hood over the blades.

The circuit breaker protects the motor from becoming overloaded and over heating. If the circuit breaker is tripping all of the time, it may be worn and require replacement. To access the circuit breaker, remove the switch from the front panel. Remove the nut securing the circuit breaker in place and then pull the circuit breaker out, through the switch opening. You can either make note of how the wires are attached or take a photo for reference later on. Disconnect the wires. You can test the circuit breaker with a multimeter set to OHMs. Place a lead on each terminal on the circuit breaker. In the ON position (button in the down position), you should get a reading and in the OFF position (button sticking up), there should not be a reading. If your circuit breaker is not doing this, then it needs to be replaced. Attach the wires to the new circuit breaker and reassemble the breaker back into the housing. Install the nut to secure the breaker in place. Reinstall the switch.