Planer: Smoke From Tool

The armature is the power-producing part of the motor and is the only moving part in the electric motor. The armature is made up of wire winding's, which can fail for various reasons and result in smoke. To examine the condition of the armature, and to perform tests on it, you will have to first remove it. Begin by taking off the side covers and the gear box cover, followed by the retaining rings on the shafts (keeping the sprockets and chain in place). Remove the sprockets and chain off of the shaft and then any spacers on the shaft. Loosen the bolt on the belt tensioner and take out the belt. Not all planers have a tensioner, so 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 cable hold-downs. Remove the bolts securing the motor housing to the planer and lift the motor up, detaching the ground wires under it. Place the motor on a bench, allowing you to work on it much easier.
Remove the brush caps and brushes from the motor. Take out the switch from the switch housing, but take a photo of the wires attachments before detaching them. Now, you can detach the switch housing from the motor housing and feed the wires out with it. Remove the screws on the back cover of the motor. Remove the retaining ring behind the pulley, on the opposite end of the motor, and tap the pulley with a rubber mallet to free the armature from the motor housing. Remove the back cover from the armature and then the spring washer off of the armature shaft. Clean the armature only with electrical contact cleaner and wipe dry. Examine the armature for melted winding's and burn marks. Burn marks indicate a smoking armature, requiring a replacement. If you wish to check the condition of the armature, there are three tests you can perform.
The first is a continuity test. With the armature removed from the unit, stand it up on a bench. Attach one end of the ohmmeter to the shaft (for ground) and the other to the bar on the commutator. Move the probe to each bar on the commutator, checking all of the bars. If the ohmmeter shows a reading on one of the bars, this will indicate a short and a bad armature.
The second test is a bar-to-bar test to determine the resistance. Attach one probe to a bar on the commutator and the other probe on the bar right beside it. There will be a specific reading for this, depending on the design of the armature. But, most importantly, there is not a large fluctuation here between the values which would indicate a fault. If there is an increase in resistance, this will indicate there is a broken, or burned out, wire in the coil. If the resistance drops, then there is a short. Move around the commutator, checking each bar.
The third test is the 180-degree test. Attach the two ends of the ohmmeter on the commutator bars, directly across from each other. There will be a specific set of readings for this, depending on the design of your unit. Again, what is most important is that there is not a large fluctuation in values, which would indicate a fault. If there is an increase in resistance, that would indicate a broken or burnt wire. If the resistance drops, that would indicate that there is a short. Continue this test on all the bars. If an armature fails any of these tests, it is recommended that you replace it.
Install the armature onto the motor housing, being careful not to damage the field as you do so. Reinstall the retaining ring behind the pulley on the opposite side of the motor housing. Reinstall the spring washer and cover on the other side. Join the switch housing to the motor housing and feed all the wires back through it. Reconnect the wires to the switch (refer to the photo you previously took). Reattach the ground wires back through it. Reattach the motor housing assembly to the planer and secure the bolts. Reattach the power cord clamps and install any spacers back onto the feed roller. Insert the sprockets inside the chain and position them onto the shafts, aligning the keyways one at a time. The hubs on the sprockets face the planer. Install the retaining rings and then reinstall the gear cover.
Reattach the belt onto the pulley and adjust the tension and tighten to hold in place. Belt installation on models without a tensioner can be tricky and require some patience You may have to maneuver the belt though some tight clearances to get to the pulleys. Feed the belt on the smaller pulley first and then the larger pulley, allowing for a much easier installation of the belt. You will need to pry the belt over the larger pulley, with a screwdriver, to get it started. You can place the tip of the screwdriver on the pulley nut for leverage only. Do not damage any 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 side panels.

A worn, slipping belt will make a squealing sound and produce smoke as it slips over the pulleys. To check the belt, remove the side cover from the planer and examine the belt. Check to see if the tension is tight. Examine the belt for uneven wear (along the sides), frays or anything else that looks out of place with it. Burn marks on a belt will be obvious.
To replace a belt, begin by looking to see if your model has a tensioner. If it does, release the tension and remove the belt and install a new one. Then, adjust the tensioner and tighten in place. If your model has no tensioner, then removing the belt can become quite tricky as clearances are tight between parts. Pry the belt off with a screwdriver on each pulley, a little way, then walk it off the pulleys. Another option is to cut it off. Manoeuvre the new belt into position – which can also be tricky on planers due to clearance issues – and place it over the smaller pulley first, a little way, then use a screwdriver and place the tip on the larger pulley nut and pry over the larger pulley, a little bit. Once the belt is started on the pulley, you can walk it on the rest of the way and then reinstall the side cover.

The carbon brushes supplies electricity to the armature by riding on the commutator. Over time, these carbon brushes will wear down and start to spark excessively – causing smoke. To check and replace the carbon brushes, remove the brush caps on either side of the motor and remove the brushes. Brushes under 1/8 of an inch need to be replaced because they are worn out. If the brushes are fine, examine them for uneven wear, cracks, chips or breakage. All of these symptoms can cause issues, including smoke. Always replace brushes in pairs. Install the brushes into the housing and reinstall the brush caps.

The field is an electromagnet used to generate a magnetic field in an electro-magnetic machine. The armature is located inside of the field and the two make up the motor. If the field is shorting out, it can produce excessive sparks, leading to overheating and melting of the windings in the field – causing the field to smoke.
To examine the field, remove the side covers and the gear box and then take out the retaining rings that supports the sprockets and chain on the feed roller shafts. Now, remove the sprockets and chain as a unit. Remove any spacers on the rollers and then loosen the bolt on the tensioning bracket and take off the belt.
For models without a belt tensioner, removing the bracket can be very tricky and will require some patience. Pry the belt off with a screwdriver, a little way, and then turn the pulleys by hand and walk the belt off. Remove the bolts securing the motor housing to the planer, followed by the cable hold-downs and 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. Detach the switch from the housing and take a photo of the wire connections before doing so – this makes for easier reassembly. Now, detach the switch housing from the motor housing and feed the wires out of the housing. Remove the screws from the rear cover of the motor, followed by 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 and spring washer from the armature shaft. Remove the screws securing the field in place and pull out the field. Clean the field with electrical contact cleaner and whip dry. At this point, you are going to examine the field for burn marks and melted winding's which indicates excessive sparking leading to overheating and a smoking field. Replace the field if you notice anything out of the ordinary.
If you wish, you can check the condition of the field by performing a couple of test. Using a multimeter, you can check the field for continuity. Set the multimeter to an ohmmeter and place a lead on each end of the coil in the field. You will have to perform this test for each coil in the field. If the reading is infinity for one, or more, of the coils, then the field is bad and requires replacement. If there is a major variance between the coils, then the field also needs to be replaced.
Install the field into the housing and secure it in place. Reinstall the armature back into the field. Make sure the spring washer is on the shaft and then reassemble the rear cover onto the housing. Reinstall the retaining ring on the opposite end, behind the pulley. Reattach the switch housing to the motor housing. Feed the wires though and connect them to the switch – refer to the photo. Assemble the switch back into the housing and install the cutter head back onto the planer, making sure to reattach the ground screw. Reattach the power cable clamps and install any spacers onto the feed rollers. Place the sprockets inside the chain and reinstall the sprockets onto the shafts, aligning the keyways. When installing, make sure the hubs on the sprockets face the planer. For easier installation, install onto one feed roller, followed by the second, and then slide it all of the way back. Reinstall the retaining rings and then the belt back onto the pulleys and adjust the tension bracket. Tighten the tension bolt to lock it in place.
Belt installation on models without a tensioner can be quite tricky and requires 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. For an easier belt installation, feed the belt on the smaller pulley first, then the larger pulley. Pry the belt over the larger pulley with a screwdriver to get it started Place the tip of the screwdriver on the pulleys nut for leverage only, to avoid damage to any parts. Once the belt is on, you can turn the pulleys by hand and walk it on the rest of the way. Reinstall the gear box cover and side panels.

As blades dull with use, they start to smoke up the wood and will change the shavings into saw dust. To check your dull blades, remove the hood assembly and take out the screws securing the blade. Most planers have a T-handle tool to remove the screws. On the other end, in the handle, are two magnets on either end of the handle, which are used for picking up the screws two at a time. It is also designed to pick up the bar and blade as well. When removing the screws, keep pressure on the bar because it is spring-loaded. With the screws removed, lift up the bar with the magnets in the handle and then do the same with the blade. Take out the springs. Clean the inside out of any debris so the new blades and bar will lay flat. Reinstall the springs and install the new knife. Most blades are double-sided, so you can flip them around. Install the bar and make sure it is positioned on the nipples to hold it in place. Install the screws at each end first, to keep the springs down then install the rest of the screws. Tighten the screws hand tight and then use the T-handle tool. You will have to do this for each blade on the cutter head. Once completed, reinstall the hood over the blades.