The Content Of The Article:

After years of trouble-free use, your machine whims you by staying inexplicably inert. The moment has come to go to the coal, to give him a heart to the work. Small excursion in unknown places.

Change the coals of a power tool

Practical advice

● When changing coals, it is imperative to replace both simultaneously.
● If you can not find coals for your machine model, look in the other brands. When troubleshooting, buy coals of slightly larger size. They are easy to read to get to the desired odds.

On all the portable power tools used by the do-it-yourselfers, the "coals" supply current to the rotating part (the armature) by rubbing on a collector. These bonding agents are made from graphite-based alloys, hence their name. These are wear parts, so we must plan to change them regularly on high demand machines. In general, this concerns primarily grinders, circular saws, electric files, or even drills.
A small, ingenious safety device will soon be found on all new machines, with the generalization of carbon brushes. On these models, the power supply of the motor is cut as soon as a coal is too worn, thus avoiding that it comes to get stuck between the bottom of its guide cage and the collector. A frequent incident, which brings a serious risk of tearing small collector copper strips. It must then change the armature or buy a new equipment.

General revision

It is advisable to regularly check the condition of the coals of all machines, taking advantage of a moment of less activity in the year, that is to say at the end of the summer. This will also provide an opportunity to dust off the inside of the housings: a maintenance operation too often neglected, much to the chagrin of ball bearings and axles.

Two coals and it goes again

On some machines, type grinder, access to the coals is from the outside, without dismantling the housing. The protective caps are easily located: diametrically opposed, they are always located on the side of the power cord, towards the end of the bulge formed by the body of the machine. A spring housed in each plug ensures the contact of the coal on the collector.
For other devices, it is necessary to disassemble the casing before reaching the heart of the machine. The heads of the fixing screws are generally cruciform, therefore easy to disassemble. As the guard, the clipping system is different from one manufacturer to another and even from one machine to another, a little trial and error will probably be necessary before you can open it.
Once the hood is removed, the two cages of the coals are easily identified: in coppered metal, they are vis-à-vis each side of the collector at the rear of the armature. Using the blade of a screwdriver, simply lift and spread the tail of a small spiral spring to clear the coal that will fall by itself by turning the machine to the side. It only remains to slip in its place the new coal that you have ordered to the after-sales service of your store, giving references the tool. The same operation is repeated for the second coal before proceeding to reassemble the crankcase.

Disassemble the housing

Disassemble the housing

Disassembly of the housing is done without difficulty. A cordless drill equipped with a suitable tip (cruciform...) avoids a tedious task. When reassembling, set the torque to minimum.

Clean the inside of the hulls

Clean the inside of the hulls

Despite the ventilation, the interior of the hulls is quickly lined with wood particles, plastic or other dust. A blow gun is needed to spare bearings and shafts.

Check the continuity of the electric current

Check the continuity of the electric current

First check: make sure the continuity of the electrical current from the plug, at the end of the cable, to the input and output terminals of the switch, in the on position.

Take out the coal

Take out the coal

A spring presses the coal onto the collector. With a screwdriver, gently pull on the last turn until you release the end. Tilt the machine to drop the coal.

Insert the new coal

Insert the new coal

It takes fairy fingers to slip the new coal into its home. Tweezers greatly facilitate this operation, especially in the case of small electrical appliances.

Replace the power cable

Replace the power cable

It's time to inspect the power cable. If the examination reveals a damaged or repaired sheath after any accident, do not save a replacement.

Optimize the power supply

Optimize the power supply

Power tools give the best of themselves if they are guaranteed a high quality power supply. Etame the ends of the strands when changing.

Check and adjust

Check and adjust

Ultimate check to make sure everything is back to normal, a vacuum setting, and here is your machine ready to go back to work for a new DIY campaign.


Video Instruction: How to replace Dewalt cordless drill brushes.