PowerPlus rotary hammer drill teardown and rebuild.

  1. Wozzaaah

    Wozzaaah The wizard of woz Staff Member

    Messages:
    15,196
    Wiltshire, UK
    Had this for a good few years and other than a knob that broke a few years ago it's been absolutely faultless until recently.
    Every now and again while drilling, the bit would stop spinning even though the motor was working fine.
    Easing the pressure on the bit would sometimes get it to spin just enough to retrieve it from the hole, fortunately everything I've been drilling lately has been to weaken it ready to break it up so if a bit got stuck I could always retrieve it eventually.
    Thought I'd try and see if I could find out what was wrong with it so set about it with my tools this morning.
    Before starting (obviously):
    IMG_4636.JPG
    Casing removal pt1:
    IMG_4638.JPG
    Motor housing off:
    IMG_4639.JPG
    Casing removal pt2:
    IMG_4640.JPG
    "Nose piece" removal:
    IMG_4641.JPG
    This is the piston which creates the hammer action. For those unfamiliar with how these work, this piston travels back and forth inside a bore, the air it displaces causes another loose piston to strike a flat ended thingy (can't think of the best word to describe it) which is attached to the opposite end of the chuck.
    IMG_4642.JPG
    The actual piston and conrod:
    IMG_4647.JPG
    For anyone wincing at the above photo, the vice isn't done up tight, it's just very lightly nipped up to hold the motor upright.

    Gearbox split:
    IMG_4644.JPG
    The pin inside the gear on the right disengages the hammer action when that black plastic lever is flipped, it pushes up inside the bore in the photo below
    IMG_4645.JPG
    The business end:
    IMG_4646.JPG
    ^This is the mechanism to engage/disengage the rotation. As it's shown there, the rotation would be disengaged, it's held together by a spring and those cutouts on the left side of that gear.

    Annoyingly I couldn't find anything obviously wrong with it but I regreased and reassembled everything and upon testing it does seem to be working fine though I'll know more when I put it to proper use again.
    If it happens again I suspect it might be something inside the nose piece so will attempt to strip that part down further, it may even be a piece of grit or something causing the rotation stop mechanism to stick disengaged.
     
    WorkshopChris, stuvy, Migmac and 3 others like this.
  2. Wozzaaah

    Wozzaaah The wizard of woz Staff Member

    Messages:
    15,196
    Wiltshire, UK
    Just thought I'd follow this up as I've been using it quite a bit lately.
    It still doesn't like drilling holes but chisels fine but.... today it decided it didn't like the motor cooling fan and threw it out of the cooling slots in small pieces.
    Unfortunately it looks like it's not available as a spare part, it comes attached to the motor armature.
    I can't complain really, it's a good few years old and has done a fair amount of hard work since I bought it. It still runs ok but obviously I'll have to be mindful of how long I run it for and give it time to cool down.
    I recently treated myself to a 15kg breaker so it will only get used for very light stuff now anyway.
     
  3. WorkshopChris

    WorkshopChris Forum Supporter

    Messages:
    5,048
    Location:
    South East Essex
    Excellent wright up,
    Rightly or wrongly I have always referred to that bit as the anvil?
     
    tom2207 and Wozzaaah like this.
  4. angellonewolf

    angellonewolf Member

    Messages:
    5,655
    Location:
    bristol england
    id like to think the next will last as long but i dout it

    ive got a screwfix titan one been good for a fair few years

    its heavy though
     
    Wozzaaah likes this.
  5. tom2207 Member

    Messages:
    2,516
    Location:
    uk northern ireland
    Hilti ,, ive two and they just work , only downside is they are both 240 so no go on sites , but again very handy round the house . These days every thing seems to be cordless and still doing very well , I just think its cheaper to buy an extension lead than a battery.
     
    Wozzaaah likes this.
  6. Wozzaaah

    Wozzaaah The wizard of woz Staff Member

    Messages:
    15,196
    Wiltshire, UK
    My 15kg one is MacAllister, I know it’s not in the same league as the pro stuff but it’s a proper beast with serious grunt and will do me fine.
    I borrowed a Makita one to knock out a few fence posts but it had a fault and would only run intermittently then it stopped working completely. Fortunately the owner said he’d been having trouble with it. Rather than hire one I thought I might as well buy one.
     
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  7. tom2207 Member

    Messages:
    2,516
    Location:
    uk northern ireland
    I normally find if I borrow one , I have to buy two

    one to replace the one I borrowed , and it broke while I had it
    and the one I should have just bought in the first place ..
     
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  8. angellonewolf

    angellonewolf Member

    Messages:
    5,655
    Location:
    bristol england
    I don't feel bad about having some cheap stuff some of its good for the occasional use infact I guess a 3rd of my stuff is cheaper stuff and most works as I expect a red power devil circular saw(had it 25 years) a lidl special rail saw one if my best is a titan breaker cost 129.99 new i went to hire a hilti breaker cost was 50 quid for one job so I known i had at least 3 jobs lined up that I was going to need it for so bought a cheap one hopeing it would last the 3 jobs its done them and earned me more than I paid for it in paying jobs and its still working
     
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  9. tom2207 Member

    Messages:
    2,516
    Location:
    uk northern ireland
    Certainly cant argue with that.
     
    angellonewolf likes this.
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