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

 

[ptsg]

Don't bother to sharpen the blades. It's not a finish mower and it will only last 30 minutes or so anyways.

Heck I don't even use blades.

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[repete]

I have two RC's. One is for grass only and the other is for trash. The grass one has a tail wheel and the other does not as I back up into some areas.

I keep the grass one (only hits grass) sharp and the other kind of dull.

Since the cutter rotates in a CCW direction, I always cut grass in a CCW direction (uncut to my left and front slightly high). By doing so I chop the grass multiple times making it easier to break down.

 

[Cycledude]

I remove the blades to sharpen them, once you figure out how to remove them it’s pretty easy, they don’t need to be very sharp.

 

[geneP]

our old sidewinder manual

Do you happen to still have that manual?

 

[Bearsixty7]

Do you happen to still have that manual?

Oh no, that was back 40+ years ago when I was a teen! I remember reading it and showing my dad it could cut hay.

I did find this that may help you, Hercules Service Parts - Agricultural equipment repair located in Minden, Louisiana - Your Rotary Mower Experts!

 

[geneP]

I have a few pages of the manual, but the part describing repacking the spindle bearings is missing. It is supposed to be quite a chore, I'd like to see the original version.

 

[kubota shifty]

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?

I sharpen mine twice a season (a few months in spring). I'm amazed you never sharpened yours. My neighbor sharpens theirs also. I use an angle grinder, lifting up the mower as high as it will go and then brace it with a 2x4 just in case. I take baling twine to keep the blade from spinning. After doing this for at least a dozen years there is still lots of blade left. It doesn't cut when it is dull and I always hit stuff as hard as I try not to.

 

[marhar]

Don't bother to sharpen the blades. It's not a finish mower and it will only last 30 minutes or so anyways.

Heck I don't even use blades.

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[marhar]

I thought you were joking until I did so research on line.

 

[SRMN8R]

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?

I hooked up my brush cutter a couple of months ago to clip the light line behind the house. I hadn't really thought about how much brush I'd been cutting the last few years, clearing trails on my mostly wooded property... but once I started trying to cut some warm season grasses and the dreaded Asian Stilt grass, I realize how horribly dull my blades had become. I ran over the grasses twice and then had to end up taking the zero turn out and cutting with that.

Yeah... got to sharpen those blades if you abuse them at all.