Jump to content

Dewalt DC987


Nathan

Recommended Posts

I have a DC987 drill that is about four or five years old now, and it's been used pretty hard.  Whenever the drill is run, even when not under any load, and in any gear, it gives off a hot electricity smell.  Like smoldering plastic or something similar.  I pulled the back cover off and checked the brushes, and they seem to be fine, about 1/2" long.  There was some carbon dust in the housing that I just blew out with compressed air, but the problem continues.  Is this caused by brushes or was the motor overheated and partially melted, or something completely different?

Link to comment
Share on other sites

This is just a guess without actually seeing it.

If the brushes are kept clear of debri, theu can cause hot spot's, or pitting on the armature surface. Everytime the brush rolls over a surface that is not flat you will see an arch flash. This is what causes the burning smell, it will lead to pre-mature failure of the motor. A new can motor for the DC987 about $38. If you have a Dewalt owned Service center near by, you can have them take a peek.

Link to comment
Share on other sites

Well, I took it apart the trigger was just dusty but I wiped it off and it seemed fine. The inside of the plastic housing had a light coating of greasy sawdust and I cleaned everything out. Then putting it back together, the transmission decided to fall apart, what a fun job it was figuring out how that goes together.  I got it all back together new grease and It seems to be a less noticeable smell, but its still there, especially if you load the drill up at all.  It does seem to really spark more than normal, what causes the armature to be pitted? It sounds like you said that keeping it clean actually causes pitting? Is it really just that worn, or should the brushes be replaced?

Link to comment
Share on other sites

  • 3 weeks later...

The "new" DCD970 is a better drill in many ways. Improvments in comfort, balance and in my opinion better ratio on the different gears. But why buy a new drill if the old one works or just need a little money on service? The dc987 is a solid drill that will be competitive for some more years. I bought a DCD960 because my old 12v dewalt started to be a little to weak and my batteries had lost something like 40 percent runtime. The batteries to that machine was to expensive compared to the drill itself. In my opinion that is not the case with the more profesionel drills like DCD970 or the old DC987. If a battery is bad it is worth to buy a new battery or put some money on service.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Member Statistics

    18,156
    Total Members
    6,555
    Most Online
    Ballen1114
    Newest Member
    Ballen1114
    Joined
×
×
  • Create New...