Best way to sharpen rotary cutter blades?

[Red Raider]

I have a 15' Rhino bat-wing cutter. Over the years, I have removed the 6 blades and sharpened with an angle grinder equipped with a flat abrasive disk (or bought new ones). It takes a long time. Tried a bench grinder once or twice, but it did'nt seem to work as good as the angle grinder. Anyone know a better, quicker and more efficient way?

 

[Renze]

nope... first thing that came to mind when i read the title of your post, was a heavy angle grinder with the 8mm thick surface grinding disks (not the thin cut-off disks)

Dont know what you're using, a cut-off disk or a surface disk, but the heavy disks do take away material a whole lot easier than a cut off, plus theres the risk of shattering the cut-off when using it for surface grinding...

I guess theres no other way to sharpen hardened blades...

 

[chh]

I generally just sharpen them while they are on the machine. I fold and lock the wings up to do those sets. With the wings up you can reach the center blades from the side. I use a 7" grinder with a grinding disc on it. It is harder to manuever than my 4" but seems to do a better job.

 

[zionview]

7 inch grinder followed by a 4 inch grinder: sharpened the wings in the transport position, blocked the hydraulic cylinder in the up position and put several 6X6s under the center section for safety. With what we ask them to do, they don't stay sharp very long!

 

[Red Raider]

Using 8" grinding disk (not cut-off). Guess I need to keep looking for a more abrasive one. Wonder if a big commercial bench would work better.