Has anyone used a belt sander to sharpen mower blades? I am using a real coarse file and diamond hone right now.
Yep, Use it all the time works great.
Whatever method, just remember not to remove metal from the bottom.
You want the cutting edge to be the lowest part.
I use a 4X36" bench top belt sander.
Just a couple of seconds for each edge.
Bought it for some woodworking,
Fast blade sharpen too. Exhaust port fits standard shop vac
One important thing to remember when sharpening blades is to keep them balanced. An imbalanced blade will wear out spindle bearings much faster, in addition to making the whole mower vibrate more. Balancing the blades on your mower is even more critical than balancing the tires on your car, because these blades turn at around 3,000 rpm at full speed.
There are a few good little tools that the homeowner can use to check blade balance. They will all check the blade for gross imbalances (at the level where you'd feel it as vibrations).
I used to mow commercially, and I invested in a pro-grade tool called the Magna-Matic balancer. You mount this on the wall, and it has a ball-bearing'ed cone that engages on the blade's center hole. You turn the blade to be horizontal and then the heavy end will sink. It's so sensitive, you have to turn off your room fans as that will affect the reading. The thing cost $150 a few years ago, so understandably it probably isn't cost-effective for most homeowners. But when you run a set of sweetly balanced blades on your mower, it reminds you of that old Norelco electric shaver commercial from years ago, which showed Santa zipping along on a Norelco over the snow-covered hills, remember that? Awesome.
one other important thing - don't sharpen the blade to a knife edge. Easy to do with a sanding setup. Leave a 1/32 flat or so.. OTW blade will easily knick when striking a hard object and be right back out of balance along with a poor cut.
This info from the boys at the Simplicity engrg test lab many moons ago..