Rotary Cutter Sharpening the blades

[marhar]

I have a 6" rotary cutter I have used for years to clear some old pasture. Like many of us I have hit a few rocks and some branches along the way. All of that being said the "sharp side" of the blades now have a bullnose profile. I have never sharpened the blades.

I went by a local shop and asked about sharpening the blades. The first fellow I spoke with looked at me like I was crazy; he said he'd never heard of sharpening the blades on a rotary cutter. The second fellow interrupted him and said they did sharpen the blades. Since I have never sharpened them they still have plenty of width.

Have you ever sharpened your bush hog blades?

How do you know when they are not worth sharpening?


My plan is to by an extra set of blades to replace my used blades. I will then have the used blades sharpened and keep as extras. Any advice?

 

[arto98607]

I've had a John Deere 430 brush hog for about 25 years and have had no reason to sharpen blades yet.
The edges are dull but seems to cut still OK.

 

[ROUSTABOUT]

I sharpen in place on the cutter with a small angle grinder. We sharpen every now and then. Not something we do all the time.

 

[David Wayne]

I sharpen mine, without taking them off. I just shorten the top link, raise it and block it up and get under there with a right angle grinder. I wouldn't replace unless they were beat bad or maybe had 25-30 percent ground away.

 

[Lineman North Florida]

I load mine on my gooseneck trailer and back the tractor up until the cutter is hanging off the back of the trailer, raise the 3 pt hitch as high as it will go with the third link shortened and at that point I can walk up under the mower and use a hand grinder to sharpen the blades, I do it probably every other year or so, sharp blades cut grass better than dull ones do.

 

[AndyMA]

Same as others occasionally with battery operated right angle grinder

Andy

 

[Topzide]

Remember to not sharpen like a knife. Just take out the rock hits or the edge folds over and is a pain to dress up!

 

[RalphVa]

I remove mine on the RC2048 every spring and sharpen on a rotary grinder. Do not actually sharpen, just reshape to get worst stuff smoothed out. Never have replaced blades. Run for a while with trail wheel off and then retorque with 6 ft piece of pipe.

 

[Doughknob]

Yep, sharpen mine every few years also. Sharper blades work better in the heavy stuff and take less tractor HP.........

 

[Bearsixty7]

This has been posted many times and I have seen it in the manual for an older "Rotary cutter".

The blades work best if not sharpened in brush and woody type weeds (Where most are used), the dull blades will shatter the stem/stalk and not be able to heal and grow. The secondary benefit is no sharp points to puncture tires.

Now if you are cutting desired grasses to keep an area neat, then sharp blades are recommended so as to not tear the blades/stalks/stems of grass, but then most people will use a flail mower or a large finishing mower or a larger ZT in such areas.

It is even possible to use some rotary cutters to mow hay, our old sidewinder manual showed to have sharp blades and to remove one of the rear panels so that the hay would be discharged out into almost a windrow. We never used it for that but most mowers or haybines today actually use multiple "mini" rotary cutters across the cutting bar.

This is some of what my Bush Hog 215 manual states,
Replace any blade that is bent, excessively nicked, worn, or has any other damage. Small nicks can be ground out when sharpening.

When sharpening blades, grind each blade the same amount to maintain balance. Follow
original sharpening pattern as shown in Figure Mnt-R-0008. Always sharpen blades by
grinding. Always sharpen both blades at same time to maintain balance. The difference in
blade weights should not exceed 1 ounce. Unbalanced blades will cause excessive
vibration which can damage gear box bearings. Vibration may also cause structural cracks
in cutter housing. DO NOT heat and pound out edge. Do not sharpen blade to a razor edge,
but leave a 1/16” blunt edge. Do not sharpen back side of blade