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View Full Version : What is the best way to sharpen blades?


Mr. Magpie
05-21-2007, 10:57 PM
Does anyone sharpen their mower blades without taking them off?

I bought a Dremel tool, with a plastic mower blade guide, thinking I could reach under and do them up without taking 'em off..... seems this little thing is not up to the BIG challenge. Not enough power I'm afraid.

Let me know if this is too much to ask. I am not lazy, I just want to maximize efficiency and employee happiness. Thanks

dcgreenspro
05-21-2007, 11:00 PM
I probably wouldn't do that, just take the extra two minutes to take them off and make sure they are nice and sharp...thing about the time you will save the next day. Work smarter not harder

Mark in MD
05-22-2007, 10:14 AM
I agree with dc.

Ironic
05-22-2007, 01:35 PM
I have to do several dozen blades every week. I take them off, stick 'em in a vice and grind 'em down with a 7" grinder. Balance is pretty important too, so I always balance them on an old Magna-Matic blade balancer.

mike r
05-22-2007, 01:42 PM
please take those blades off and get a professional to sharpen them.
the reason for this is YOU must BALANCE these each time you sharpen your blades. if by chance your in need of a blade grinder (sharpener) talk to gerd
magna-matic he'll fix you up with a grinder and balancer.

cariboulou
05-22-2007, 11:45 PM
why is it so important to balance the blades? ive sharpened my own blades for years and never blalnced any of them!

Mark in MD
05-23-2007, 08:34 AM
It's not as important as with a 21 inch mower, but if your blade isn't balanced, it will eventually prematurely wear out the bearings in your blade spindles -- and it could eventually lead to warping of your blade deck.

Balancing is cheap and easy and only takes a few secs.

scott's turf
05-23-2007, 09:40 AM
Maybe I am having great luck but I have never balanced a blade in my life and have also never had to replace a spindle in 15 years. My bobcat walk behinds have over 2000+ hrs and my exmark laser has about 1600 hrs so far.

How long do most spindles last? I am not advicating against balancing the blades but I just don't think that it is all that important.

Ironic
05-23-2007, 09:55 AM
for some reason, Bobcats and Exmarks hold up better to imbalance and general abuse, in my experience.
some others don't hold up so well, like John Deere 1145.
years ago, our old mechanic never took the time to balance our blades. and on 2 mowers, we were going through 3 spindle assemblies a year.
but now I'm the mechanic, and I'm kinda nitpicky about details, like balancing.
now those same 2 mowers have gone 2 years without a spindle problem.

another plus, is that the decks vibrate less when the PTO's on.
theoretically, it frees up horsepower, and saves fuel...since it takes less effort to keep a balanced mass spinning.

lawnmaniac883
05-23-2007, 01:02 PM
please take those blades off and get a professional to sharpen them.
the reason for this is YOU must BALANCE these each time you sharpen your blades. if by chance your in need of a blade grinder (sharpener) talk to gerd
magna-matic he'll fix you up with a grinder and balancer.

Balancing is about useless as far as a Z is concerned, IMO. On a 21'' push where your hands are being jarred from the handles due to imbalance ok but not on some 16 or 20'' blades spinning from a 200lb deck.

Ironic
05-23-2007, 01:20 PM
Balancing is about useless as far as a Z is concerned, IMO. On a 21'' push where your hands are being jarred from the handles due to imbalance ok but not on some 16 or 20'' blades spinning from a 200lb deck.

then why bother balancing the tires on your car?
or balancing an engine?

800wildcat
05-23-2007, 02:06 PM
And Z's turn much higher blade speeds than a 21". Out of balance weight rises geometrically with rpm increase.

Mic_bug
05-23-2007, 04:49 PM
then why bother balancing the tires on your car?
or balancing an engine?

You mean you balance the air pressure in each tire?

topsites
05-24-2007, 01:46 AM
It has to do with racing, once you get a vibration it results in a slight loss of rpm's, an out of balance blade could cost you 50 rpm's or so, if you want top notch performance then this is an issue. In addition, it could be the cause for tingling fingers, fuel consumption stays the same regardless of rpm's... As for the bearings, it's the high speed sealed ones always give me the most trouble, it's not such a big deal on greasable ones.

As for sharpening, if cost is an issue, a handheld grinder is a good tool for it, but yes, take them off.
You could leave them on but you still can't 'see' the edge, plus taking them off regularly ensures that when they absolutely have to come off, they come off easier (the nut tends to freeze onto the bolt if left on too long).
If cost is no issue, then to answer the question, an RBG is the BEST tool for it.

You mean you balance the air pressure in each tire?

well I kinda make sure they're all filled to the same psi :laugh:

scott's turf
05-24-2007, 08:23 AM
It has to do with racing, once you get a vibration it results in a slight loss of rpm's, an out of balance blade could cost you 50 rpm's or so, if you want top notch performance then this is an issue. In addition, it could be the cause for tingling fingers, fuel consumption stays the same regardless of rpm's... As for the bearings, it's the high speed sealed ones always give me the most trouble, it's not such a big deal on greasable ones.

As for sharpening, if cost is an issue, a handheld grinder is a good tool for it, but yes, take them off.
You could leave them on but you still can't 'see' the edge, plus taking them off regularly ensures that when they absolutely have to come off, they come off easier (the nut tends to freeze onto the bolt if left on too long).
If cost is no issue, then to answer the question, an RBG is the BEST tool for it.



well I kinda make sure they're all filled to the same psi :laugh:

All my spindle bearings have been the sealed ones and have never replace one, ever.

Stillwater
06-12-2009, 04:41 AM
wow it is aparent that some hear took the short bus to school..... after reading some of these posts :dizzy::dizzy::dizzy::dizzy::dizzy:

TYCINC
06-12-2009, 05:49 AM
Says the dumbass reviving a 2 year old thread.

ericmcj31
06-12-2009, 06:00 AM
I just buy new blades....I don't fool with sharpening them---at the price I can buy them at, it is crazy to sharpen b/c I have NEVER had one keep its edge like a new blade out of the box

Roger
06-12-2009, 06:51 AM
I just buy new blades....I don't fool with sharpening them---at the price I can buy them at, it is crazy to sharpen b/c I have NEVER had one keep its edge like a new blade out of the box

New blades are never sharp. The first thing that I do with new blades (and has been mentioned by many others who do likewise) is sharpen them before mounting. I don't understand your comment about a sharpened blade not keeping an edge. Some of my blades have been sharpened many times (hundreds?), and still keep an edge. My hand mower has a newly sharpened blade mounted every morning before it leaves for work. My w/b and Z blades get sharpened a couple of times per week. Why would I buy new blades every day/every week? I'm missing something about your comment regarding new blades.

Ruben Rocha
06-12-2009, 07:16 PM
New blades are never sharp or balanced.
Do what you want but I use magnamatic to sharpen and balance every blade,
Just one item on my Z I noticed is less pulleys replaced per year. Let alone one spindle replacement and you will get the picture.