Sharpening John Deere blades

Discussion in 'Magna-Matic' started by K/B, Mar 9, 2012.

  1. K/B

    K/B LawnSite Senior Member
    Messages: 480

    Hi, I wondered if you have any suggestions for sharpening John Deere blades. We have a MAG-8000 bought new last year, and we have some difficulty with the wheel getting out of round and make excessive "chatter" when sharpening certain John Deere blades. This seems to be because we have to remove the worktable and use the mulching platform, which doesn't provide as good support. The reason we can't use the table is because of the blade design, they have a curve that rides up on the outside edge of the table. I see you have special tables available for the MAG-9000, but I don't see any for the MAG-8000. I was thinking about modifying a table, but I thought I'd check first and see if you had any recommendations.
  2. rdelawter

    rdelawter LawnSite Member
    Messages: 3

    Hello K/B,
    I purchased the same 8000 sharpener and also the blade cleaner in February of this year.
    The 2nd set of blades I sharpened were the John Deere blades you have described. I had to take a lot off to get them back in shape and had problems as you have.
    I ended up using my angle grinder to take the worst off and then finished them on the 8000. Rather disappointed.
    The JD blades are of good pretty hard steel so I ordered the fastest cutting grinding wheel and that helped with the material removal but that curve in the blade is a pain.
  3. rdelawter

    rdelawter LawnSite Member
    Messages: 3

    I also had the wheel chatter problem and used a dressing stone to true the wheel, several times.
  4. Magna-Matic

    Magna-Matic Sponsor
    Messages: 839

    Hello All,

    To be clear I assume you are both talking about the John Deere "Edge-Extra" blade - it appears to have an "up-side-down V" shaped bend down the center?

    If this is the blade the best way to approach it due to this unique bend is to use the mulching blade worktable, not the flat one. You can use either the one inch or half inch wheel. Still take one pass from inside of the edge outward like a curved mulching blade. This will allow you to sharpen these. Also bias more pressure downward on top of the blade to keep CONSTANT CONTACT with the rounded worktable surface - this will prevent chattering.

    If either of you would like to talk in more detail feel free to call.

    Thank you,
  5. K/B

    K/B LawnSite Senior Member
    Messages: 480

    Yes, that's the blade I'm talking about. And the mulching platform is what I was using, (flat table removed) with the half inch wheel. I've tried keeping strong downward pressure on the blade, but I just can't stop the chattering. When I dress the wheel, it grinds smoothly for a minute or so before slowly starting to chatter, until it's so bad that the blade will hardly stay in contact with the wheel, between the chattering and having to constantly dress the wheel, it wears down extremely fast. This is while keeping so much down pressure on the blade that my arms hurt afterwards, also I tried keeping the blade in extra light contact with the wheel, but it didn't seem to help.
    The reason I think it's because it needs more work table support is because with the flat table on, I can only sharpen the first 2" or so of the blade, (because of the blade design) but there is no chatter. It's when I pull the flat table off and use the mulching platform that it starts making trouble.
    The only thing I wasn't doing as described above, is sharpening from the inside outward only. I was going both ways.
    I think I'll try cutting one corner off the flat table, and see if it allows me to sharpen these blades easier.

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