[metro-hp_48]

Thought I had heard it all, and would like to see how many here, would agree with this (MTR's) therory;

"yes sir, it goes like this...a 36" cut nicer than a 32" and a 52" cut even nicer than a 48". The width and length of blade provide a smoother cut, and of course the stripe, can you beat a stripe of a 52" Z or a 52" hydro WB? never."

Any thoughts on this from anyone else?

 

[metro-hp_48]

I myself say it would depend more on deck design, blade type, tip speed, speed of mowing, type of grass, ect. I may be all wrong, but that's just my theory. Width and length? hmmmm.

 

[Richard Martin]

Does this mean that one of those single bladed 30" homeowner riders would provide a better looking cut than every other mower available. I don't think so.

 

[metro-hp_48]

That's the way I took his theory, Richard. Makes no sense to me, either. Maybe he can explain in more detail.
That I have to hear.

 

[David Haggerty]

The biggest difference I've seen is the longer the blade, the more difficult they are to keep in alignment.

Dave

 

[jajwrigh]

I think there are so many factures that contribute to a good cut that its difficult to accurately pinpoint the main cause.

 

[LawnMower]

Originally posted by metro-hp_48
Thought I had heard it all, and would like to see how many here, would agree with this (MTR's) therory;

"yes sir, it goes like this...a 36" cut nicer than a 32" and a 52" cut even nicer than a 48". The width and length of blade provide a smoother cut, and of course the stripe, can you beat a stripe of a 52" Z or a 52" hydro WB? never."

Any thoughts on this from anyone else?

I don't think its the length of the blade. Its the length of the deck. You could have a 61 inch deck with 5 small blades in there, and would still give a great cut.

Also the larger mower with large tires makes a difference too. Large tires ignore irregularities in the lawn. Wide decks smooth out irregularities in the lawn. Big mowers leave less wheal marks. All these things tend to make a smoother looking cut, I think.

 

[metro-hp_48]

Sounds logical to me LawnMower.

 

[barnard]

There is some truth to the blade length longer is better theory. Example given a 10 inch blade with a blade tip speed of 20,000 rpm 1 inch in from the tip the speed of the blade is 20% sloweror 16,00feet per minute 4 inches in the speed is 80% slower or 4,000 feet per minute.The distance from blade center to tip is 5 inches. Now take a blade20 inches in length. 10 inches fromcenter to tip. The blade speed is 10% less per inch from tip. 1inch from tip blade speed is 19,000 4 inches from tip blade speed 12,000 vs. 4000 for the 10 inch blade. It is a factor in the cutting performance of the blade because not all cutting is done at the tip.If it were blades wouldn't be sharpenend 4or 5 inches. just the last 1/2 inch would. In general longer blades cut better but if you took your 48 inch walk behind and it had two 25inch blades instead three 17 s thedistance between front and back wheels would have to be increased by about 8 inches. Moreso on a 61 inch cut . this would mean more scalping and less manuverability . There are many trade ofs in deck design. If shorter were better given the competition in the industry some manufacturer woul be putting 4,5 or six blades on there decks.

 

[DLCS]

Originally posted by barnard
There is some truth to the blade length longer is better theory. Example given a 10 inch blade with a blade tip speed of 20,000 rpm 1 inch in from the tip the speed of the blade is 20% sloweror 16,00feet per minute 4 inches in the speed is 80% slower or 4,000 feet per minute.The distance from blade center to tip is 5 inches. Now take a blade20 inches in length. 10 inches fromcenter to tip. The blade speed is 10% less per inch from tip. 1inch from tip blade speed is 19,000 4 inches from tip blade speed 12,000 vs. 4000 for the 10 inch blade. It is a factor in the cutting performance of the blade because not all cutting is done at the tip.If it were blades wouldn't be sharpenend 4or 5 inches. just the last 1/2 inch would. In general longer blades cut better but if you took your 48 inch walk behind and it had two 25inch blades instead three 17 s thedistance between front and back wheels would have to be increased by about 8 inches. Moreso on a 61 inch cut . this would mean more scalping and less manuverability . There are many trade ofs in deck design. If shorter were better given the competition in the industry some manufacturer woul be putting 4,5 or six blades on there decks.

Ditto

 

[barnard]

Sorry math error. Blade speed one inch in from tip on a 20 inch blade would be 18,000 not 19,000.

 

[joshua]

the deeper the deck the better the cut from my experience. my 60 gives a better cut than my 52, especially at the end of the day and the 60 doesn't get much grass suck on it in the corners so to speak.

 

[Pecker]

Things that make you go "hmmmm". . . .

 

[dishboy]

Originally posted by joshua
the deeper the deck the better the cut from my experience. my 60 gives a better cut than my 52, especially at the end of the day and the 60 doesn't get much grass suck on it in the corners so to speak.

So why do walkers cut nice?

 

[David Haggerty]

Originally posted by LawnMower
I don't think its the length of the blade. Its the length of the deck. You could have a 61 inch deck with 5 small blades in there, and would still give a great cut.

Also the larger mower with large tires makes a difference too. Large tires ignore irregularities in the lawn. Wide decks smooth out irregularities in the lawn. Big mowers leave less wheal marks. All these things tend to make a smoother looking cut, I think.

That describes my Toro 580-D exactly.
5 blades on the front deck, all 21"
31" drive tires at 11 psi

I've owned a couple of similar mowers with 24" blades.
One was a 12' bat wing Alamo the other a 15' batwing Howard Price 180.
Neither one's cut could compare to the Toro. I think the pattern is flatter. Less area for one blade to cover. Of course the Toro has extensive baffeling and those great big cast steel spindle housings too.
But in my opinion, 21" is the optimum blade length.
That machine can mow a cow pasture in a single pass make it look as smooth as a fairway on a golf course.
It's kind of funny. Just about every new job I get, someone shows up with their golf clubs. Then proceed to loose every one of their balls. Because there are still holes out there you could break a leg in. The balls just disappear! I can spot them the next time I mow from way up on the mower, but they're almost impossible to find from the ground. I used to have a huge golf ball collection. I finally gave them all away. And folks have wised up. Just because it looks smooth, it isn't a driving range.

Dave