Electric Power Drill Problems

Discussion in 'General Electronics Chat' started by Maketronic, Nov 24, 2012.

  1. Maketronic

    Thread Starter Active Member

    Mar 21, 2009
    Hi All, Firstly my appologies if I have posted this in the wrong place.
    I have a Makita HP2010N Power Drill that I bought with a number of other drills second hand. The 2 other drills were easy fixes being just short brushes that need replacing. This drill however proved to be more difficult.
    Initially the drill had a burnt out field winding (or stator winding). I purchsed genuine Makita replacement winding and new brushes and re-assembled the drill and still no go. The drill buzzes and hums and trying to turn the chuck it would appear that it is providing holding torque on the rotor when the power is on.
    I have tried alsorts including changing polarity of field coils with respect to rotor and putting power direct onto the motor instead of via the vari speed trigger but still no go.
    Just as background the drill is a universal or series wound motor so no aux windings, start capacitors or cetrifugal switches. I am in New Zealand so the supply voltage in question is 50hz 230VAC.
    The stator of the drill visibly appears in good condition but I have no idea what other tests I could perform on it. The following link shows a parts diagram for the drill showing the reccomended wiring http://www.ereplacementparts.com/makita-hp2010n-hammer-drill-parts-c-97_16247_384.html
    I know many would just write off this drill but it is a high quality metal gearbox drill that still sells her for over $500NZD so I am keen to perservere with it.
    Any Ideas would be much appreciated.
    Regards Bruce
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    the drill will have two windings, make sure they are wired in series in the correct polarity to each other, if not the drill will try to turn both ways at the same time. Also you can do a continuity on the rotor windings with the brushes.
    Maketronic likes this.
  3. Maketronic

    Thread Starter Active Member

    Mar 21, 2009
    Hi Dave.

    I had tried that already but didnt seem to work.
    Strangely I tried (only for a short time) to remove one of the field windings so there was no way it could be wrong and it turned (rather roughly of course). I then re-assembled with the second winding and it went but poorly. I dont know what had gone on becuase the wires are colored so there is no way I could have assembled it different.
    I put my multimeter on the brushes and turned the rotor one segement at a time and it varied between approx 4.6 ohms and 8.6 ohms. Dont know what it should have been but surely each should have been closer to ther others than that.
    Maybe pointing to a rotor fault, sadly may have to right it off.
    Thanks for your help.