Another Blade Sharpening ?

Discussion in 'Mechanic and Repair' started by groundsmechanic, Jun 26, 2008.

  1. groundsmechanic

    groundsmechanic LawnSite Member
    Male, from Lansing, MI
    Posts: 120

    Hey all.

    I am the mechanic for our grounds crew and have been for the last couple years. I have a couple questions about how you all do your blade sharpening.

    Currently I use a dewalt angle grinder to get out as many of the nics as I can, then switch to a B.G.-121 rotary blade grinder. It usually takes me 15 - 20 mintues to do a set of 3 blades. I have 8 Toro 345 mowers with 3 blades each, 2 Exmark Lazer-Zs with 3 blades each and a Toro 4700-D with 7 blades. Plus the Land Pride with 9 blades.

    So a total of 46 blades. At 5 mintues each, thats almost 4 hours. Based on some of the other threads I have read, 60 blades runs anywhere from 1 to 1.5 hours. Plus, the 4700 blades have a twist to them so I cannot get a very good cut and the exmark blades are too long for the machine.

    I only sharpen blades maybe every 50 hours, maybe longer. Quality of cut doesn't really matter here, so long as they get the grounds done and the grass is short.

    I would prefer to keep them sharpened more but I would need to have an assistant just to do blades so I can keep up with all the other stuff they break.

    My supervisor has been talking about trying to get an automatic sharpener for me, but he has been saying that since before I got here. I have yet to see anything "automatic" in my searches. I see the Magna-Matic sharpeners and from what I read, are very good. Any ideas on automatics? Any ideas on my technique?

    Cliffs Notes: 5 mintues/blade = too long, automatic sharpener existance?, technique recommendations? Magna-matic 8000 or 9000?

    BTW, money isn't really a factor.
     
  2. MowerMedic77

    MowerMedic77 LawnSite Bronze Member
    Posts: 1,164

  3. jkason

    jkason LawnSite Senior Member
    Posts: 548

    Get a bigger (more torque) grinder and put the biggest wheel you can on it.
    Either you're really anal about the sharpening, are being too dainty or the blades are just hammered when they come to you.

    If they're hammered, sharpen more often - and start charging the crew for damage on the units.

    If the blades are too long for your grinder, you need a new grinder. Don't be dainty. work them blades on the wheel. Throw sparks - you want to almost bog down the wheel of the grinder. Don't let them get hot, though, or they lose the heat treatment.

    If money is no object - http://www.bernhard.co.uk/rotamaster.0.html
     
  4. Happy Frog

    Happy Frog LawnSite Bronze Member
    Posts: 1,224

    I used a home made rig using a belt sander from Harbor Freight Tools for a few months and it worked great but with the sandy soil I mow, I have to sharpen my blades after only one hour of mowing (they become badly rounded in two hours).
    So after a lot of research, I bought a RBG-1012-C commercial grinder ($640 at Russo Equipment on eBay).
    It looks like the smaller grinders but this monster is about 142 lbs and has a 12" ceramic wheel mounted on a 1 H.P. commercial duty motor. They have only one grinder bigger than this one and it weights 195 lbs with 14" wheel and 2 H.P. motor (way too heavy for me to move around).
    It still take me a while to sharpen my blades but it is much quicker than the belt sander. The biggest difference is that I can push the blade against the wheel without slowing down the motor and I get a real good cutting edge on my blades.
    Without a continuous blade cooling system, I don't see how any device (including the over priced Magna-Matic 9000 and 8000) can sharpen blades faster: The faster you want to go, the more you have to push the blade against the wheel and the more heat you create on the blade edge (you need a bucket of water close by to cool down your blades all the time).
    You just have to find the right amount of pressure to grind the blade without burning the edge and loosing the temper.
    Unless you have real sandy soil like me, it should take you but a minute or two to sharpen a blade with this grinder :drinkup:
     
  5. DiyDave

    DiyDave LawnSite Bronze Member
    Posts: 1,695

    Try a Neary or RBG blade grinder, it'll about cut your time in half, for under a grand.:waving:
     
  6. Breezmeister

    Breezmeister LawnSite Bronze Member
    Male, from South Jersey
    Posts: 1,570

    Here is a link to another thread that might help, every one will have there opinion on what works " for them " like me :) Also, there is a second link in that thread to another that might help as well

    http://www.lawnsite.com/showthread.php?t=199967&highlight=grinder

    Just keep it simple
     
  7. Two Seasons

    Two Seasons LawnSite Senior Member
    Posts: 791

    We've been in business a short time and made the investment in a MAG-8000 from Magna-Matic. Got the stand and the seven ball-bearing balancer too. I can clean and sharpen 12 blades in 50 minutes. We amortized out the cost and did the deal. Well worth the money. Precision sharpened/balanced blades makes a big difference in: cost of fuel (less parasitic loss), healthier grass (less tearing), and probably is less costly when maintenance time comes into play.

    And your employees will enjoy less vibration in the machine!
     
  8. groundsmechanic

    groundsmechanic LawnSite Member
    Male, from Lansing, MI
    Posts: 120

    The grinder I currently have is an RBG-121, the smallest rotary grinder they make. I can stop the motor pretty easily, plus what it does stop, it has discolored the metal from the heat. The blades are usually torn up pretty bad by the time I get to them. Some of the workers will destroy a set pretty quickly since their IQ rivals that of the grass they are cutting. They hang the decks over the curbs and grind them on the concrete, hit stones, mow dirt and mud. I don't sharpen them as often as should be because I don't have the time. I am the only mechanic for over 40 pieces of equipment so I stay busy with that.

    Thanks for the link, I will be looking into that one also.
     
  9. groundsmechanic

    groundsmechanic LawnSite Member
    Male, from Lansing, MI
    Posts: 120

  10. tomo

    tomo LawnSite Senior Member
    Posts: 660

    hello ,
    If u have either
    1/red neck operators [causing physical damage to blade ] or
    2/ blade sharpening at long intervals

    The condition of the blades will always be poor prior to resharp
    Therefore more metal is required to be removed at each service
    The priority is then a machine that will torerate this
    eg [long constant heavy use ]
    my own experience with dedicated blade grinders suggests that a min of 1 1/2 hp is required .[oregon or the 2hp RBG]
    Cooling of the blade tip in a container of water every pass or every 2nd pass is required .

    Although there is an automatic feed blade sharpener available it is not water cooled therefore only usefull for slightly worn blades .aargh !!

    tomo:waving:
     

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