Recommend a sharpener for a homeowner

Discussion in 'Homeowner Assistance Forum' started by matt_m, Apr 9, 2013.

  1. Magna-Matic

    Magna-Matic Sponsor
    Posts: 827

    Hello All,

    I would like to correct the information on "payback" or ROI (return on investment)

    The MAG-9000 is $697 for 2013.
    At a cost of $4 per blade (which is low) $697 dividied by $4 = 174 sharpenings.

    Divide 174 by 3 blades per deck (commonly) = 58 sharpening for one mower.

    There are about 32 weeks of cutting in one season (more for southern states)

    So even if you are a home owner, with one commercial mower a MAG-9000 is paid for in about 1-1/2 seasons.

    If you have two mowers with 3 blades each, the MAG-9000 will be paid for in ONE SEASON.

    Now I've based this on a home owner with a 3 blade commercial mower, if you are a commercial cutter you'll be sharpening every 1-2 days NOT once per week, so then the payback drops to less than half a season.

    If you take the 32 weeks and divide it by 5 working days = 160 days.
    160 days divided by sharpening every 2 days = is 80 sharpenings in a commercial cutter's season.

    Now remember above it only took 58 sharpenings to pay for the MAG-9000, so if you have a few mowers, or cut longer than 32 weeks the payback is even shorter.

    Keep in mind too, that the MAG-9000 will probably outlast all the mowers in a commercial fleet. Rather than buying a sharpener/bench grinder from China that might only last one or two seasons.

    Thank you,
  2. Magna-Matic

    Magna-Matic Sponsor
    Posts: 827

    The MAG-1000 has a cone blade hole range of 5/16" to 1-1/2"
    It is possible to balance an object down at 3/16" but it is getting down to the edge.

    Thanks for the question.
  3. Grassmechanic

    Grassmechanic LawnSite Silver Member
    Posts: 2,697

    I own a MAG8000 and can vouch for it being, hands down, the best sharpener that I've used (and I have used several) for both straight and mulching blades (all my mowers utilize mulching blades).Thumbs Up
  4. matt_m

    matt_m LawnSite Member
    Posts: 35

    You're suggesting I need to sharpen once a week mowing < 4 acres?

    I based my number on sharping 5x a summer--once a month May, Jun, July, Aug, September. Maybe there's a 6th. 58 sharpening with your numbers is 10-11 years, not 1? With realistic sharpening costs, its really more like $100-120/year so more like 6-7 years. Still, not saying that's not worth it, just a lot harder to justify.

    That 3-wing blade has 5/8 or 1" arbor--can't remember off the top of my head. I'm wondering about the physics though. I suppose the blade would be balanced when it will stay in position with any of the three wings pointed up--otherwise when a heavy wing is on one side or the other, it would want to rotate to the bottom?
    Last edited: Apr 10, 2013
  5. matt_m

    matt_m LawnSite Member
    Posts: 35

    One more question--do you have any dealers in the Toledo, OH area?

    Anyone know of a RBG dealer in the Toledo, OH area.

    Ann Arbor is reasonable too.
  6. Magna-Matic

    Magna-Matic Sponsor
    Posts: 827

    Hello Matt,

    If you are looking at having a cut, and not torn lawn. A lawnmower blade should be sharpened every 8-12 mowing hours.

    Depending on rain, temperature, type of grass, where you are in the USA, the mowing season varies. So it is not the best to use a time frame like a "week" - I only used "weeks" in my example to make the calculations more simple, and a shorter post.

    We are located in Wisconsin, and it is possible to mow as early as April, and as late as November, but other years that can be June to Sept. If your are in southern FL or CA you can mow all year long. Some years a lawn might be mowed once per week, sometimes it may require 2.

    There are many variables that can change the calculation, I was just trying to provide a quick example so you can see that it does not take years and years to justify our equipment.

    Thank you,
  7. Magna-Matic

    Magna-Matic Sponsor
    Posts: 827

    Hello Matt,

    Regarding balance and understaning the physics I strongly recommend this post where similar questions were asked.

    The heavy portion of the blade will rotate to the 6 o'clock position. It may not necessarily be one of the tips. You have to think of this tri-blade or even a lawnmower blade like a DISC or CIRCLE. There can be too much weight in any of its four quarters.

    It often confuses people because a lawnmower blade has the shape of a rectangle, and most commonly the tips wear. This causes the "horizontal balance" to be the one that changes and must be corrected.

    Let me know if you have more specific questions about the balance.
  8. DiyDave

    DiyDave LawnSite Bronze Member
    Posts: 1,695

    Though I don't have the magna-matic grinder, I will vouch for the balancer, does a real good job, I just grind off a little more on the heavy side, each time, till it balances. I got a free blade grinder, from a relative, and a stack of wheels, that were mis-priced, way low, from harbor freight, and I ain't gonna spring for a new grinder, till I use up all them wheels, or the motor goes, cause I am CHEAP! I will buy the magna-matic then, or when the economy improves!
  9. matt_m

    matt_m LawnSite Member
    Posts: 35

    I went ahead and ordered a Magna-Matic balancer from Russo Power Equipment. Got a line on a Wall BG-121 grinder for about the price of a Bradley that's pretty far away, but the seller agreed to meet me 1/2 way.

    I'm not unconvinced that the Mag 9000 might not be a better buy due to future resale value (it would be practically new if I only ever sharpen my blades with it for the next, say 10 years.) Walls seem to be a hard sell based on dates on CL ads and Ebay completed sales at well under 1/2 of new.

    Any thoughts on the viability of doing some sharpening on the side for others to offset some of the cost? Worth the hassle?
    Last edited: Apr 11, 2013
  10. Grassmechanic

    Grassmechanic LawnSite Silver Member
    Posts: 2,697

    I do. If you got the time, why not? only takes a minute or two to sharpen a blade.

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