Considering the purchase of the Magna-magic 9000 to hopefully get more life out of the blades. A lot of the grass I cut is bahiagrass on sandy soil which takes a toll on blades.
The sand sure does do a number. I use a 4100 with mid-mount and ZTR's (757,797,960 and 997) on the property so have a lot of blades to sharpen. Currently I just run till the ends are gone and change them out. The grinder is pricey but replacing blades a couple of times a year for each unit is not cheap either.On mine by the time the blades need sharpening they've been sandblasted away to nothing. I just buy them in bulk on ebay and usually just replace them. Very very seldom do I have enough blade left to sharpen them.
I cut about 35-40 acres every couple of weeks(actually an ongoing process each week with a few acres every other day). Lots of trees, ponds, buildings, fences , banks and ditches. I have a 5100M with MX7 cutter that I use on the wide open areas and when it 100 degrees outside!I'll be following this. I also have bahia grass in sandy soil and I sharpen my blades every other week. I mow 4 acres weekly and buy new blades every season. I just tried out the gator blades today and they work very well cutting but they sure throw a lot of stuff out of the chute. I had to clean the screen on the radiator 3 times today.
I have always purchased my blades from my local John Deere dealer so I realize they are more expensive but like to support local business. I go through at least two sets for each mower each year so that equates to 10 sets of blades ( three 60" decks and two 72" decks). I have angle grinders and bench grinder but I am the worst at keeping a constant angle. Failed to mention that I have to send out the blades on my Bandit XL 065 wood chipper so another consideration and blades on two 84" rotary cutters (however have only replaced one set in last 10 years). Anyway, still on the fence with this idea. On the other hand, can never have too many tools!This little dude in expensive to own, when you consider how many mower blades it would take to pay for it. At $750.00 up front cost, and the cost of what three (average mower uses) blades averaging $50.00 per set you would sharpen, you would get 15 sets of blades to average the cost of the Magna-Matic 9000 unit.
I have a hand grinder and I sharpen the three blades on my 54" deck once a year in the fall after the mowing season. I own a JD 345 and a JDZ710A and I hate to sharpen these blades. Some times, I just buy new blades for each mower and pay the price(s). I buy Stens brand blades.
Do you use a jig or just eyeball it? As I posted, I am terrible at maintaining the proper angle so have probably messed up more blades than I have improved so the main reason I purchase new ones. Have a number of blades in my scrap metal stock that maybe could be salvaged. The old blades are maintained as sets in the scrap metal bin.I have found that a 4 inch angle grinder with a flapper style sandpaper disc gives me excellent control of the edge geometry for blade sharpening. The sanding discs allow very slight grinds or heavier metal removal if needed without throwing too much heat into the blade. I use a flat file to put a small flat on the cutting edge when I am done with the grinder. Not much money and fast results.
Really like this post and your later follow up post.I have found that a 4 inch angle grinder with a flapper style sandpaper disc gives me excellent control of the edge geometry for blade sharpening. The sanding discs allow very slight grinds or heavier metal removal if needed without throwing too much heat into the blade. I use a flat file to put a small flat on the cutting edge when I am done with the grinder. Not much money and fast results.
Thanks for responding. I went back and looked at six sets of old blades and really none of them could be salvaged due to excessive wear on the tips of the blades. A direct result of the grass and sandy soil.I clamp the blade in a bench vise and take very light cuts to witness that I am keeping the primary angle intact. I don't feel that variations in the cutting angle are really that critical for cutting grass. I am more used to production metal cutting where a degree change can be proven to enhance or reduce performance dramatically.
A more abrupt angle will provide a stronger cutting edge that resists chipping or rolling over better than a shallow angle that will cut easier and cleaner but will chip, roll and dull sooner.
You could set a small machinist protractor or similar to the edge angle of a new blade and use it to check as you go. As I stated earlier, there is probably little consequence to not producing a perfect factory cutting angle.