Mower blade orientation make a difference?

[MuncyBob]

I remove my blades a few times each year. Sometimes for sharpening and other times I install some old beat up blades when I plan to mow pasture or trails. Even though it's a finish mower deck, if I take care I can clear trails and small brush/saplings fairly easily.
This last time that I put my good blades back on I decided to make the outer blades parallel to each other and then the center blade at 90* to them. It seems I'm getting a better cut and much less wind rows when the grass is a bit thick/tall. Is this my imagination or what?

 

[aczlan]

If you have a drive belt on the deck itself it makes no difference and the next time you hit a log, rock, etc, they will go out of alignment.

Aaron Z

 

[TripleR]

Yep, it won't take long for the orientation to change, or at least it doesn't on ours.

 

[MuncyBob]

Maybe I just did a good job last time I sharpened them.

 

[aczlan]

Maybe I just did a good job last time I sharpened them.

Probably, its amazing how much difference sharp blades make.

Aaron Z

 

[MossRoad]

Yeah. I never sharpened my blades for years...... then I did and oh my what a difference it makes. Now I do it a couple times a year.

 

[J_J]

I remove my blades a few times each year. Sometimes for sharpening and other times I install some old beat up blades when I plan to mow pasture or trails. Even though it's a finish mower deck, if I take care I can clear trails and small brush/saplings fairly easily.
This last time that I put my good blades back on I decided to make the outer blades parallel to each other and then the center blade at 90* to them. It seems I'm getting a better cut and much less wind rows when the grass is a bit thick/tall. Is this my imagination or what?

Just pure imagination, as the belt and pulley will have slippage, and the blades after use could be at any angle, and blades could also turn on the shaft due to bolt tightness..

I had one mower, a Troybuilt that had a cogged belt and pulley, and the blades had to be perpendicular to each other, or they might touch/bang each other.

As far as sharpening blades, you can cut a tomato with a sharp knife, or you could karate chop it, but what a difference.

Those people that say that they never sharpen blades are not cutting, but ripping. Besides, it takes less HP using sharp blades.

 

[MoKelly]

As far as sharpening blades, you can cut a tomato with a sharp knife, or you could karate chop it, but what a difference.

Those people that say that they never sharpen blades are not cutting, but ripping. Besides, it takes less HP using sharp blades.

So, what does "sharp" mean to you? I bought a new set of blades for my ZT. The blades were not "sharp" as I would define the word. I could hold and squeeze the blades without fear of getting cut. The dealer said specifically that the blades should not be sharpened before installation and that a blade that could cut paper was too sharp, would dull very quickly and is unnecessary.

I installed without sharpening and the grass looks cut too me vs. torn. I am not real picky about the grass -- my only issue is that it all gets cut and there are no stragglers.

MoKelly

 

[cqaigy2]

I imagine if you sharpen to the point of cutting paper, the edge would have less strength because the cross section would be quite small.

 

[woodlandfarms]

The second a sharp blade hits something that is not nice an;d soft, it gets dull. I don't feel I hit anything on my lawnmower but at the end of the year the blades are dented up good.

As I understand it, brush hogs tend to not have sharpened blades, for two reasons. One is that good luck keeping that edge if you are using it for its design, the second is that by breaking, instead of cutting, you increase the chance of killing the plant, which tends to be the more desireable result when brush hogging.

I am going to sharpen, but at the moment I am mired in a dozen other projects so the property is getting long long grass....

 

[aczlan]

As I understand it, brush hogs tend to not have sharpened blades, for two reasons. One is that good luck keeping that edge if you are using it for its design, the second is that by breaking, instead of cutting, you increase the chance of killing the plant, which tends to be the more desireable result when brush hogging.

Another is that a sharp blade will slice saplings off vs shattering them like a blunt edged blade will. A sliced sapling could go through a tire unlike a shattered one.

Aaron Z

 

[J_J]

I would think a new blade is a sharp blade.

However razor sharp is not desired, nor is a dull flat sided blade, or the tips worn down..

 

[ponytug]

The new PT brush hog blades are not sharp; they have about a 1/16-1/8" radius at the front of the bevel. That is to say the blade is ~3/8" thick, with a leading edge bevel down to 1/16-1/8", where it is unsharpened and radiused.

From personal experience, I think that having a sharp blade if you are cutting brush is risky, because sooner or later, you will hit a sapling just right and it will end up with a knife edge on it that will slice your tire. That said, you don't want a totally round edge for HP and efficiency reasons.

All the best,

Peter

I would think a new blade is a sharp blade.

However razor sharp is not desired, nor is a dull flat sided blade, or the tips worn down..

 

[J_J]

I do believe some of you are mixing up brush blades and finish blades.

I cut lawns for about 20 years, and sharp blades are necessary, or your customers will notice the shredded look and can your but. You want the blades sharp enough to make the cut grass to almost disappear.

I also have a bush hog and would not give it a sharp edge as it will dull rather quickly.

I have installed many bush hog blades and they are somewhat sharp, at least the ones I buy are.

If you want to shred, do so, and if you want to cut, then you know what to do.

 

[bcp]

I think I'll go sharpen the strings on my trimmer. It should cut lots better.



Bruce

 

[MoKelly]

I think I'll go sharpen the strings on my trimmer. It should cut lots better.



Bruce

Trimmer RPM's are over twice as fast as mower blades. Faster the RPM the duller the surface can be and cut vs. shred.

MoKelly

 

[cqaigy2]

Trimmer RPM's are over twice as fast as mower blades. Faster the RPM the duller the surface can be and cut vs. shred.

MoKelly

I've notice some string isn't round and has "sharp" edges. Maybe Bruce could use that instead of sharping the strings on his trimmer. :laughing: