Sharpen Rotary Mower Blades?

[mcmxi]

If something gets dull, it gets sharpened or replaced as appropriate.

This has and continues to be my approach when it comes to sharpening anything with a cutting edge. I like maintenance but I have no interest in sharpening knives, drill bits, chainsaw chains, flail hammers, rotary cutter blades, chisels or even scissors, unless the performance or results are less than satisfactory. I have a spare set of blades for the rotary cutter, but don't swap them out and sharpen the set in use unless it's necessary.

 

[JimmyJazz]

I have never even looked under much less sharpened the blades on mine . Eight years of ownership. I once added some oil to the gearbox and in the process lost the rubber filler hose inside the gearbox. Still, so far so good.

 

[Flintknapper]

I have never even looked under much less sharpened the blades on mine . Eight years of ownership. I once added some oil to the gearbox and in the process lost the rubber filler hose inside the gearbox. Still, so far so good.

Hah.....sometimes we do more harm than good. I've had days like that.

 

[Flintknapper]

This is the kind of stuff I routinely mow with our rotary cutter. Sometimes worse, sometimes not, but pretty average (except for the log which was moved shortly after the pic was taken).
View attachment 92220

^^^^^^

Should be very easy to cut. Green, moist foliage, not very 'stemy'. I wouldn't expect you'd need to dress your blades very often (if ever) for that.

Conversely, what I mow is very different. Look at everything to the left of the green grass.
The grass came up in areas I cleared (with a sharp blade) taking my time and doing a good job in one pass.

I think you will see what a tangled mess of vines, weeds and young saplings it is. Some of it as tall as the seat on the tractor. I took this video and pic today 12/15/22

But IF you do a good job....you can have native grass repopulate (by itself). This is a spot cleared off exactly 45 days ago. It looked just like the stuff in the video before being mowed.

Would NOT have happened if mowed with dull, worn out blades on a rotary mower. The grass would still have grown 'some' through and around the Mat of shredded debris and saplings, but it would look like hell and I'd have to do it all over again this spring.

 

[NCL4701]

Soft, moist vegetation there. Easily mowed with just about anything. Looks fine.

Doesn't require any Drama and Hyperbole in rebuttal. In your case I wouldn't expect to have to 'dress' your rotary blades very often....if ever.

But YOUR situation is very different than mine and that of others.

What would be of more use would be a pic of the rotary blades on your mower. I'd wager the edges are not as round as a coke bottle...right? IF it were....I expect you'd be getting very different results.

No one is suggesting you dress the blades per a calendar, but also not buying into the idea that they NEVER need to be sharpened because so and so said so on a YouTube video.

It is your privilege to do as you like on your property and use your equipment as you see fit. As for trying to do a better job (within reason), take pride in our work, or even be a better person, yes I think those are worthy goals.

But everyone was raised different and have different ideals, that is well understood and appreciated.

IMO your results look just fine (if that matters).

Agree different circumstances warrant different measures. And some of it depends on the preference of the user.

However, that doesn’t translate to lazy or not taking pride in one’s work because someone else doesn’t follow procedures to your circumstances and preferences.

Edit: Doesn’t mean their “cheap” either (you said that also). You may have noticed I actually agreed with your suggestion sharp is better in some circumstances prior to my “rebuttal”. I also already said I have dressed them back to original profile when needed.

I agree with you on the issue the post is truly about. I disagree with you calling others lazy, cheap, and not taking pride in their work in this circumstance.

 

[Elliott in GA]

It really just goes to the point that reasonable people can have disagreements about many things - even some things more important and complex than the sharpness of rotary cutter blades without attacking other people's moral center.

Unfortunately, it not only blue haired young people that try to turn every discussion into a morality play in which they have the high ground.

I guess those of us that question the value of sharp rotary cutter blades will be labeled - sharp phobic or sharp deniers. I could not think of something good that ended with "ist".


Edit - Dullist

 

[Flintknapper]

I disagree with you calling others lazy, cheap, and not taking pride in their work in this circumstance.

I did not infer every person is Lazy, Cheap or does not take pride in their work. I said it is often the reason some folks do not dress the blades. Do you deny some folks are Lazy, Cheap or don't take pride in their work?

It is a 'if the shoe fits wear it' proposition. And of course those guilty of it....will be the first to object.

In the end....it is every person's choice. I am not here to tell anyone how it should be done, that is YOUR choice. But we can have meaningful conversations about the pros and cons of things. That's how we learn, by sharing ideas and experiences.

Too often a point of view (especially a dissenting one) is taken to mean 'you are wrong and I am right', when in fact it was offered as nothing more than a different way to do something....and the reasons for doing so are given in support of that position.

 

[Flintknapper]

It really just goes to the point that reasonable people can have disagreements about many things - even some things more important and complex than the sharpness of rotary cutter blades without attacking other people's moral center.

Unfortunately, it not only blue haired young people that try to turn every discussion into a morality play in which they have the high ground.

I guess those of us that question the value of sharp rotary cutter blades will be labeled - sharp phobic or sharp deniers. I could not think of something good that ended with "ist".


Edit - Dullist

The subject of 'effectiveness' for the task at hand is not a MORAL issue in any way. Nor is discussing the intentional failings of some folks. The 'truth' is not always convenient or pretty.

What is 'unfortunate' is when a subject "morals in this case' gets misapplied, where it had no bearing to begin with.

As for 'ist'.

I will remain an optimIST.....and I think that's pretty OK.

 

[ex-Sea Bee Mike]

I have a 5' Land Pride. My local dealer claims the blades never need to be sharpened ( at least that's one persons opinion ).

Do you all sharpen your Rotary Mower glades and if, how do you do it?

Heard that if you don't sharpen your blades, any stubs or small stumps from trees and shrubs will be shattered and won't be sharp enough to puncture your tires.

 

[Flintknapper]

Heard that if you don't sharpen your blades, any stubs or small stumps from trees and shrubs will be shattered and won't be sharp enough to puncture your tires.

Even brand new blades (factory profile) don't cut such that a sharp stub is left.

 

[RalphVa]

I've been removing the blades and sharpening them using a fixed rotary grinder every spring for 18 years.

"Sharpen" is wrong word. I even their sides out and leave a blunt edge.

Getting too old to do this. Plan to replace the old Frontier with a new Landpride this spring and maybe do the blade "sharpening" less frequent.

 

[Flintknapper]

I've been removing the blades and sharpening them using a fixed rotary grinder every spring for 18 years.

"Sharpen" is wrong word. I even their sides out and leave a blunt edge.

^^^^^^

Agreed.

I will bring my to as close to the factory 'profile' (new blade) as I can get them.

Which is anything but sharp.

But a far cry from some I've seen which have an edge about as round as your thumb.

I cut a lot of very thick Blackberry vine, Greenbrier and Cherokee Rose. A dull blade will NOT do much more than beat them down and it puts a noticeable strain on my compact tractor. Unless you mow where there is a lot rock, there is nothing a 'dull' blade is going to do better than a properly dressed blade.

If you don't wait 110 years to 'dress' the blades....it doesn't take that long and can usually be done once a season.

 

[SDT]

Heard that if you don't sharpen your blades, any stubs or small stumps from trees and shrubs will be shattered and won't be sharp enough to puncture your tires.

Generally true, with exceptions of course, which is why dull blades are preferred when mowing saplings of any size.

 

[Captain13]

i don’t “sharpen” my blades in the sense that they have a knife or sharp edge. I use Woods equipment and follow their guidelines which are: 1. Follow original profile. 2. The leading edge of the blade will be flat and 1/16 high. That goes for their rotary and grooming mowers. These blades will hold that profile for a long time before it rounds off. It gives a clean cut and reduces stress on the gearbox and PTO.

i looked at the Land Pride user manual and in the blade maintenance section, it states to remove nicks and balance the blades when sharpening. So Land Pride must expect that owners will be sharpening their blades. Like someone mentioned earlier, I sharpen when I need to sharpen. my winter routine is to check everything and do whatever maintenance I need to do during the season down.

Last thing….it was either the Woods or the Land Pride manual that mentioned failure to do blade maintenance can cause early gearbox seal failure, no doubt due to imbalance and excessively dull blade stress on the gearbox.

 

[racer86y]

Yep! I agree 100% with this. I cut about 30 acres over the summer months at my place and a friend's place. I have two sets of blades for the rotary cutter and keep a sharp set on hand at all times.

How do you get the blades off?Are the bolts and nuts holding blades on left handed threads?

 

[Flintknapper]

How do you get the blades off?Are the bolts and nuts holding blades on left handed threads?

There 'might' be some units out there with a left hand thread, but the vast majority are a standard right hand thread (counter clockwise to loosen).

 

[Elliott in GA]

How do you get the blades off?Are the bolts and nuts holding blades on left handed threads?

You will probably need between 200 and 600 ft-lbs to remove the nuts. Many people use a high power torque wrench or a torque multiplier ( a decent one costs about $250). The advantage to a torque multiplier is that it allows you to later torque down the nuts to spec. - often 400 ft-lbs.
I plan to buy this one when the time comes:

NEIKO PRO 03715B 1/2" Drive Torque Wrench, 1100 Foot-Pound Heavy Duty Torque Multiplier Wrench, Cr-Mo and Chrome-Vanadium

PRO-GRADE TORQUE MULTIPLIER: This lug nut torque multiplier provides powerful torque to cleanly bust rusted or frozen fasteners with the rated force that standard wrenches cannot produce. HEAVY DUTY BUILD: The torque produced by this torque wrench multiplier is from the chromium molybdenum head...

neikotools.com

 

[Flintknapper]

You will probably need between 200 and 600 ft-lbs to remove the nuts.

I certainly agree that the nuts can offer a 'challenge' when it comes time for removal.

IF the nuts have not been removed recently then you likely will be dealing with not only the dynamic torque figure (used to tighten them) but also some amount of corrosion on the threads.

The 'break away' torque can be considerably higher than the torque used to install the nuts in that situation.

Often times a cheater bar, torque mulitplier or powerful impact wrench are needed to break the nuts loose.

I've done it all three ways....but use my impact whenever possible.

*please excuse the green*

 

[GreensvilleJay]

Always wondered if the 'group' that doesn't sharpen their mower blades ever tried to cut facial hair with a dull straight razor ?

 

[Elliott in GA]

Those are two extremely similar items used for almost identical purposes - facial razor and rotary cutter.