Any dewalt 18v cordless drill experts?

Geo-TH,In · Aug 23, 2014

My 18v cordless dewalt dc925 hammer drill motor took up smoking yesterday. I took motor apart, polished commutator, put it back together, it works fine. However, the brushes are more than half gone. I will never take motor apart again to replace brushes, not worth it. Some wear on communtator segments too.

So, off to do an advanced search on ebay, but it not, new, lowest price.

To my surprise, the seller on ebay says my motor is used on a 14.4v drill, but it can be use on 18v. When I think about it, I have two tractors with 6v starters running on 12v, but that's only for a few seconds, not continious.

Does anyone know if this is correct? Has anyone used 14.4v motor on an 18v drill? If so, I will have a spare motor sitting on my shelf soon. My motor looks identical to this motor including the red plastic rod on the back.
George
new DC925 motor

teddy52food · Aug 23, 2014

As long as you keep the voltage up, motors run fine. It is when the voltage drops and the amps go up they get overheated & fail. Another proof the magnetic field comes from the atoms of the conductor excited by the voltage & not from the current.

guido · Aug 23, 2014

Hello George Marsh,

Next time you take a brush motor apart, take the brushes and give them the profile shown in the drawing. Leading and and trailing edges will allow the brushes to bounce when worn. When the brushes are profiled that way, the motor will draw less amps...........Try it! By the way the motor will work just fine at both voltages, but the power transistor (mosfet) on the trigger may not. I do have one of those motors around, not sure what voltage though.............

Guido.

Geo-TH,In · Aug 23, 2014

Hello Guido,
Not that easy to do. I try to post a pic of brush. The brush is connected to brush holder with a spot welded braded wire. The brush holder isn't that easy to replace either, it is crimped in place. For the price difference, I think I'll just get a new motor.

Look at the post above, go to the motor on ebay. I had to use a hammer and chissel to remove end bell. Hammer and anvil to put it back together. Took about 3 hours start to finish. It was difficult getting motor connected to the 3 speed tranny too. george
dewalt brushes/holder all one.

guido · Aug 23, 2014

Hello George Marsh,

Been there done that. They are not designed to be taken apart! End bell on the brush side appears to have a very hard metal, not easily pried apart for sure. But like I said, next motor you take apart do the brush trick it works!

Guido.

Geo-TH,In · Aug 23, 2014

Agree, some brushes you can replace without taking anything apart. Can't reverse the dewalt brushes. The braded wire has to fit in a grove in brush holder. They only go in one way and the braded wire is spot welded to brush holder.

guido · Aug 24, 2014

Hello George Marsh,

You don't have to reverse the brushes. Just scrape both edges with a exacto knife about a 45* angle to take the sharp edge off,

Guido.

will in texas · Aug 24, 2014

if you google dewaltservicenet type in your model number and it will take you to a page click on diagram it has an eploded veiw of the drill then find brushes and order the brushes are like 5 bucks and shipping is like 5 or 10 bucks a whole lot cheaper than a new drill

Any dewalt 18v cordless drill experts?

Geo-TH,In

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teddy52food

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guido

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Geo-TH,In

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guido

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Geo-TH,In

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guido

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will in texas

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