Mowing Sharpening and Balancing Mower Blades

   / Sharpening and Balancing Mower Blades #1  

hwp

Platinum Member
Joined
Dec 16, 2001
Messages
643
Location
St. Catharines, Ontario, CANADA
Tractor
Kubota F2400
I have a Kubota F2400 with a three blade RC60 mower deck. What is the best way of sharpening and balancing the mower blades. In the past I sharpened them using a bench grinder but lately I have been using an angle grinder. Is one way better than the other? Or are there even better ways? I have read somewhere that the blades should have a flattened surface of 1/64" on the leading edge. How do you do this?

I check the balance of the blades by putting them on a bolt and spinning them by hand in the vertical plane? Should they be checked in the vertical or horizontal plane? Should the check be static or dynamic?
 
   / Sharpening and Balancing Mower Blades #2  
I use a 4" angle grinder with a flimsy disc with the blade clamped in a vice... The flimsy disc kind of follows the original edge better than a hard stone... I use a nail to check balance. I have a blade level but prefer the nail. If you put the blade on the nail and it won't stay horizontal then it's not level.. kind of simple way to check them....
 
   / Sharpening and Balancing Mower Blades #3  
Hoosier_Daddy, Just a bit more detail for us if you could? I'm new to this, but I'd really like to sharpen my blades myself. /w3tcompact/icons/blush.gif How do you use the nail? I'd be grateful for the help. Kent
 
   / Sharpening and Balancing Mower Blades #4  
Along with Kent, I would like any input people have on blade sharpening tips. I now do my own, but I sure would like to hear any advice about improving my skills. If this has been discussed before, maybe someone could help by pointing out the thread.
Thanks, Will.
 
   / Sharpening and Balancing Mower Blades #5  
I've sharpened mower blades with both a 6" bench grinder and a 4.5" angle grinder (blade held in a vise when using the angle grinder). Either one works pretty well. It may depend on the design and shape of the blade. Because many of them are turned up on the back side to "lift" the grass, they can be a little awkward to slide straight across the guide on the bench grinder. I suppose the most important thing is to try to grind a little at a time to avoid getting the blade too hot and ruining the temper (and since I sharpen them pretty sharp, I've burned the edge of a few/w3tcompact/icons/frown.gif).

As for balance, I do about the same thing as Hoosier Daddy. I use a very small round shaft screwdriver, no bigger probably than the nail he uses. I simply stick the screwdriver shaft through the bolt hole in the center of the blade and holding the screwdriver horizontally, and the blade horizontally, see if the blade stays horizontal when I turn loose. If one end droops, it must be heavy and I grind a little more off that end.

As for the 1/64" flat leading edge, I don't worry about it on lawnmower blades. If you want to grind off a little flat edge, that's fine, or just don't grind it down really sharp to start with. That flat leading edge just won't get dinged up as quickly or easily as a really sharp edge, but if all you're cutting is grass and weeds, I kinda like a sharp edge. Brush hog (rotary cutter) blades are another matter, of course.
 
   / Sharpening and Balancing Mower Blades #6  
I just sharpened the blades for 3 point mower. I picked up a 4" flap grinder wheel at Harbour Freight. I have sharpened my own blades for a long time. This was the quickest and slickest that I have ever done it.
 
   / Sharpening and Balancing Mower Blades #7  
Bird uses a screwdriver and that would work.. I just pound a finish nail into the work bench and hang the blade on it. If the blades have bent angles on them you may need a little longer nail.... Hold the blade horizontal and let go..... The heavy end gets more ground off.... I like the flexible wheel with the angle grinder because it doesn't seem to heat up the blade as fast. If the blade starts to change color, back off and let it cool. You could take the temper out of the steel if it gets too hot....
 
   / Sharpening and Balancing Mower Blades #8  
Thanks Bird, jhburke, & Hoosier_Daddy. I'm glad you, gentlemen replied. I was just a bit unclear about balancing the blades. And I'm assuming the best tool is a right angle grinder? Also the Harbour Freight catalog is very comfortable in my hands. I've ordered from them for years. Thanks Again Kent
 
   / Sharpening and Balancing Mower Blades #9  
Steelfan,I use a very Hi-Tech blade balancing system myself.Couple of pieces of plastic that will cost you close to 2 bucks at about any Hardware Store.

The sides of the cone are graduated to accept about any sized blade,it will quickly show you which side of the blade needs to be fine tuned.

Before sharpening I always try to take the grass "build-up" off the blades with a bench grinder equipped with a wire brush.Also use a hand file too really put that finished edge on the blades after hitting them with a 4" hand held.
 

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   / Sharpening and Balancing Mower Blades #10  
Another look...
 

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