Let's talk about blade sharpening?

[Bange]

LOL... the subject is controversial, but the 30° seem pacified...

At least you could see how the profile of the sharpening is, which depends on the damage.

 

[slomo]

My 4 cents on sharpening.

I use a hand file myself. Takes a few minutes to get a blade back to fighting weight. New files obviously work faster than older dull ones. I can pull a file from the tool box, few slaps on both sides and I'm done. Not looking for shaving sharp blades here. Just a good bevel clean up.

No reason to fire up some super expensive electric grinder. These are lawn mowers, not the space shuttle (Taryl). I can have a blade sharpened roughly in the same time as pulling a grinder out and plugging it in. Look at the bevel, set your sharpening angle and finally remve TOO MUCH material. Now you are into balancing for quite a while...... And your blades all have smiles to them now compared to simple hand files. More grinding to correct the smiles. Now you've just removed a bunch of life from that blade.

Summation, you burn through blades a lot faster with grinders than with hand files. Most people don't even check for sharpness when done. T

Do you run a mower shop?
Most folks on this forum fall into two categories. Homeowners and shop owners. Each will have their own way to do things. Sharpening 150 or so blades with most of them beat to hell with a file wouldn't be profitable. I need to be able to sharpen a 3 blade mower in 10 minutes or less.

So why even waste the 10 minutes sharpening with your grinder? Just throw on new blades. Much faster than grinding and balancing. If it's all about speed....

No I do not have a mower shop.


Best was to sharpen a blade is install a new one.

 

[BTBO]

I don't know the correct way to sharpen a blade, but I'll describe mine... what's yours?

In fact, sharpening is not a very important item for many users, because even if the blade is not sharp, the cutter will shred the grass or any tree leaf... but the result is not satisfactory, in addition to causing greater consumption with more passes and even damage to the deck as a whole.
To those who don't sharpen, but change it after noticing an inefficiency, congratulations... it's the most correct way... but expensive.
Let's go...

With the blade off the deck, clamp it with a clamp on the workbench and clean (rust, glued and dry grass, animal manure, etc...), on all surfaces, using a grinder with flap disc, wire disc, etc.
After cleaning, I change the disk for an iron grinding disk (carburundum, diamond, aggressive flap, etc...) and grind at approximately 45° until I get a good edge.
After satisfactory sharpening, I move on to the balancing stage, an important procedure to keep the deck serene, without unnecessary vibrations that can cause loosening of screws, premature wear of pulley bearings, noise, etc.
To do this, just fix a rod with a rounded profile in a vise or workbench and hang the blade through its hole... the photos speak for themselves...

Cleaning the blade
View attachment 64029View attachment 64030
Cleaning up will make balancing easier at the end.

Sharpening...
View attachment 64031


Balancing

Blade one...
View attachment 64032
Very good...
View attachment 64033

Bade two...

Oops! Necessary adjustment...
Mark the side and remove material to make it lighter... preferably not on the sharp part.
View attachment 64036
View attachment 64036
View attachment 64038
View attachment 64039

Until equilibrium is achieved, several attempts can be made...

The end of the blade must be given special care, as it is the first to attack the grass... in any case, the edge is lost along the entire stretch due to stones, stumps, sand, sidewalks, hard fruit seeds and other objects. ..

I too clean the blades as best I can with wire wheel / brush, then use a 4.5" grinder w/a 60 grit flapwheel. I THINK the correct cutting angle is 30`. I use my $150 MAGNA-MATIC to balance. It is unbelievably sensitive, which explains my frustration having to keep checking balance so often. Sure, paying that much to balance blades is arguably overkill, but the cost of replacing spindles is something I hope to not have to do any time soon.

 

[Freddie21]

I don't know the correct way to sharpen a blade, but I'll describe mine... what's yours?

In fact, sharpening is not a very important item for many users, because even if the blade is not sharp, the cutter will shred the grass or any tree leaf... but the result is not satisfactory, in addition to causing greater consumption with more passes and even damage to the deck as a whole.
To those who don't sharpen, but change it after noticing an inefficiency, congratulations... it's the most correct way... but expensive.
Let's go...

With the blade off the deck, clamp it with a clamp on the workbench and clean (rust, glued and dry grass, animal manure, etc...), on all surfaces, using a grinder with flap disc, wire disc, etc.
After cleaning, I change the disk for an iron grinding disk (carburundum, diamond, aggressive flap, etc...) and grind at approximately 45° until I get a good edge.
After satisfactory sharpening, I move on to the balancing stage, an important procedure to keep the deck serene, without unnecessary vibrations that can cause loosening of screws, premature wear of pulley bearings, noise, etc.
To do this, just fix a rod with a rounded profile in a vise or workbench and hang the blade through its hole... the photos speak for themselves...

Cleaning the blade
View attachment 64029View attachment 64030
Cleaning up will make balancing easier at the end.

Sharpening...
View attachment 64031


Balancing

Blade one...
View attachment 64032
Very good...
View attachment 64033

Bade two...

Oops! Necessary adjustment...
Mark the side and remove material to make it lighter... preferably not on the sharp part.
View attachment 64036
View attachment 64036
View attachment 64038
View attachment 64039

Until equilibrium is achieved, several attempts can be made...

The end of the blade must be given special care, as it is the first to attack the grass... in any case, the edge is lost along the entire stretch due to stones, stumps, sand, sidewalks, hard fruit seeds and other objects. ..

Time to clean that work area, Dude. Safety first.

 

[*CPB*]

The goal when using a Magna-Matic balancer isn't to get the blade to be motionless, it's only to get it to move very slowly. If you get motionless then that's just a bonus. Their balancer is the equivalent of a calculator that goes out 100 decimal places, whereas a nail is like a calculator that does whole numbers only.

 

[Freddie21]

My 4 cents on sharpening.

I use a hand file myself. Takes a few minutes to get a blade back to fighting weight. New files obviously work faster than older dull ones. I can pull a file from the tool box, few slaps on both sides and I'm done. Not looking for shaving sharp blades here. Just a good bevel clean up.

No reason to fire up some super expensive electric grinder. These are lawn mowers, not the space shuttle (Taryl). I can have a blade sharpened roughly in the same time as pulling a grinder out and plugging it in. Look at the bevel, set your sharpening angle and finally remve TOO MUCH material. Now you are into balancing for quite a while...... And your blades all have smiles to them now compared to simple hand files. More grinding to correct the smiles. Now you've just removed a bunch of life from that blade.

Summation, you burn through blades a lot faster with grinders than with hand files. Most people don't even check for sharpness when done. T

So why even waste the 10 minutes sharpening with your grinder? Just throw on new blades. Much faster than grinding and balancing. If it's all about speed....

No I do not have a mower shop.


Best was to sharpen a blade is install a new one.

Penny saved is a penny earned, especially if machine is at a shop.

 

[StarTech]

The goal when using a Magna-Matic balancer isn't to get the blade to be motionless, it's only to get it to move very slowly. If you get motionless then that's just a bonus. Their balancer is the equivalent of a calculator that goes out 100 decimal places, whereas a nail is like a calculator that does whole numbers only.

I agree it is very sensitive but with experience you can or at least I can get the blade near perfect balance fairly quickly. It is strange to new be so far out of balance which explains some of the problems I have encountered over the years. Just started using it this season after 13 yrs of using one of those cone balancers. Even the cone was better than the nail method.

 

[Johner]

I don't know the correct way to sharpen a blade, but I'll describe mine... what's yours?

In fact, sharpening is not a very important item for many users, because even if the blade is not sharp, the cutter will shred the grass or any tree leaf... but the result is not satisfactory, in addition to causing greater consumption with more passes and even damage to the deck as a whole.
To those who don't sharpen, but change it after noticing an inefficiency, congratulations... it's the most correct way... but expensive.
Let's go...

With the blade off the deck, clamp it with a clamp on the workbench and clean (rust, glued and dry grass, animal manure, etc...), on all surfaces, using a grinder with flap disc, wire disc, etc.
After cleaning, I change the disk for an iron grinding disk (carburundum, diamond, aggressive flap, etc...) and grind at approximately 45° until I get a good edge.
After satisfactory sharpening, I move on to the balancing stage, an important procedure to keep the deck serene, without unnecessary vibrations that can cause loosening of screws, premature wear of pulley bearings, noise, etc.
To do this, just fix a rod with a rounded profile in a vise or workbench and hang the blade through its hole... the photos speak for themselves...

Cleaning the blade
View attachment 64029View attachment 64030
Cleaning up will make balancing easier at the end.

Sharpening...
View attachment 64031


Balancing

Blade one...
View attachment 64032
Very good...
View attachment 64033

Bade two...

Oops! Necessary adjustment...
Mark the side and remove material to make it lighter... preferably not on the sharp part.
View attachment 64036
View attachment 64036
View attachment 64038
View attachment 64039

Until equilibrium is achieved, several attempts can be made...

The end of the blade must be given special care, as it is the first to attack the grass... in any case, the edge is lost along the entire stretch due to stones, stumps, sand, sidewalks, hard fruit seeds and other objects. ..

Have seen new blades without the fine sharp edge, which does not last long at all. Maybe so the new owner does not cut hands when putting them on. Would you know the reason?

 

[Johner]

30deg edge will last longer, a 45deg. will slice better. Take an axe and try each angle see how each cuts. New blades come with a blunt edge I think for safety reasons.

 

[garyoldfart]

I invented and patented a sharpening jig for mower blades in the 1990's.
Your Wife can sit down and sharpen one handed with this device.
Perfect blade every time.
I could not get the price down enough for everybody to afford one. Quit making them
but I have parts and know how if anyone cares to take over
Mini-Miller is what I called it...A Mini Milling Machine.
You want sharp blades...This is it!
Pic is of a yard I mowed with sharp blades and My 1951 Farmall Cub 14hp tractor.
regards gary