Which Blade Grinder ??

Discussion in 'Lawn Mowing' started by adam71234, Oct 25, 2005.

  1. adam71234

    adam71234 LawnSite Member
    Posts: 24

    OK guys,

    I know this question has been kicked around a little, but I have searched on here a lot and only found a small amount of info on the different grinders. I need help from you guys. Which grinder should I buy?

    Let me preface by saying that we will sharpen only about 10-15 commercial blades per week. This amount will probably grow slowly. I am looking at the $250-$400 range .5 HP grinders all the way up to the $1000 magna-matic. I just need to have some more 1st hand input on the cheaper Oregon models, RBG, and others before deciding.

    Are all .5 HP grinders to weak to get out nicks (this includes the Oregon, RBG, and Magna)? If not which 1HP should I buy?

    Any help would be greatly appreciated.

  2. Gumby

    Gumby LawnSite Member
    Posts: 59

    I've been using a Magna-matic 9000 since the beginning of this year and like it alot. No problems so far and it doesn't seem to be too weak to get the job done. Bought their balancer too and like it as well. I'm doing about 12 to 20 blades a week and it's really cut down on the amount of time I spend with this chore.
  3. topsites

    topsites LawnSite Fanatic
    Posts: 21,653

    As a solo op I now use Chicago Electric's 4.5" angle grinder for $30 from Harbor Freight Tools, doing 12-15 blades/week on average, less in summer, 18/week max. 30 minutes per session, if cut in half at $30/hour for maintenance, would take close to 3 years to pay for a 1000-dollar thing which is why I've never bought one.
  4. Full throttle lawn care

    Full throttle lawn care LawnSite Member
    Posts: 151

    I also bought the 9000 combo package and think it works great! I saw the ballancer on ebay for 125.00 compaired to 190.00.
  5. DEEJ

    DEEJ LawnSite Member
    Posts: 230

    Are you trying to remove all nicks?

    I never grind enough to take out all the nicks. Otherwise I would be grinding the blades away at an incredible rate for nothing.

    I grind enough to get a nice edge, and the nicks come out in time, as successive grindings get close to them.
  6. LandscapeFreeorDie

    LandscapeFreeorDie LawnSite Member
    Posts: 6

    Sometimes you just need to spoil yourself and when it comes to a grinder, nothing spoils you downright like the magnamatic. This amazing machine will grind out half inch chunks taken out of my blades by rocks and it will do it quick. When my wife heard that I spent a grand on a sharpener she said, "Jon you must be crazy, a thousand dollars on a grinder?!" To which I replied honey, please get me a beer. Better make it two.

    Better make it a magna matic
  7. topsites

    topsites LawnSite Fanatic
    Posts: 21,653

    Far as nicks, I soon found out it is best to sharpen the blades the SAME way everytime and let nicks work themselves out over time... As a rule, 2-3 sometimes 4-6 sharpening sessions and the nick is gone because otherwise you take off a LOT of steel THEN you take that SAME amount of steel off the OTHER side as well, to me this considerably shortens the life of the blade... NEVER take out a nick for the sake of taking it out, let it work itself out over time is what I do.

    Btw, IF you get a grinder that IS powerful enough to take off THAT much steel then you will likely MELT the steel of the blade with the HEAT build-up, so MORE power isn't necessarily better... I like the lowest-amp angle grinder does fine it just takes TIME while it helps prevent those black spots and red-hot edges, helps maintain the temper of the steel.

    With sharpening, a bit of patience is key as this is the secret to a razor's edge.
  8. keperkey

    keperkey LawnSite Member
    Posts: 33


    What disks do you use?
  9. MBDiagMan

    MBDiagMan LawnSite Senior Member
    Posts: 852

    A few weeks ago, wacolawnsupply was running an incredible clearance deal on an Oregon unit for about $257 or something.

    Good luck,
  10. topsites

    topsites LawnSite Fanatic
    Posts: 21,653

    I use grinding discs, NOT the thin cut-off wheel but the one I use I'm not sure exactly how thick but it's the THICKEST... I always figured I wanted as thick a disc as I can get because with the old DeWalt 400, that's 5.0 amps (not 0.5 like someone else said but 5.0) spinning out 10,000 rpm, I do NOT want a cut-off wheel that can fly apart sending little pieces flying about, one get stuck in my neck (thou some here might enjoy that rofl).

    I've been meaning to use a finer grit, someone mentioned I should try a plumbing store (?) because I don't like the coarse grit of the Type 27 sold at all Lowe's / Home Depots, even the Chicago Electric came standard with a Type 27. Since it is raining and COLD today, I'm going out in a few to go look for one of these fine-grit wheels. The THIN discs are usually known as cut-off discs, I use the grinding discs, MOST grinders come with one Type 27 grinding disc pre-installed or in the box.

    The secret, regardless of grit, is to grind at an almost flat angle (you can't get perfectly flat because the bolt will hit the blade) and to ALWAYS grind at the same angle so the disc wears evenly and at the SAME angle. Once the disc is worn-in, it develops this angled but flat edge as it wears, hard to describe without a pic but that's what you want is basically you build it a new edge at a slight angle as it wears in.

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