| Author |
Message |
    
Mike Duwe
Member
Username: Mikeduwe
Wi
Registered: 10-2006
Post Number: 2898
| | Posted on Thursday, April 30, 2009 - 11:00 am: | 
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Getting close to the first cut of the year here in WI.
I bought my 345 last year with new blades late in the season so I didn't need to sharpen them.
I will before I start cutting this year.
Few questions for those that have been cutting grass longer than I have been alive.
What do you use to sharpen them? Dremmel with the little adaptor, angle grinder, bench grinder?
Do you balance your blades, if so how?
Do you sharpen the cutting edge to a point, or leave it a little blunt?
Anything else? |
Nick Holmes
Member
Username: Corvettedion
IA
Registered: 5-2007
Post Number: 174
| | Posted on Thursday, April 30, 2009 - 12:19 pm: |
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Mike,
I've always felt the best way to sharpen mower blades was the old fashion way, with a good flat hand file. you can monitor your angle, not get the metal too hot, and not take off too much material.
just my opinion though.
nick |
Jim Briney
Member
Username: Lodogg2221
IN
Registered: 1-2006
Post Number: 3102
| | Posted on Thursday, April 30, 2009 - 12:29 pm: |
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Mike, I use a bench grinder with an attachment I made from some scraps. I use the arm that came with the grinder that the little "table" attached to and just cut a piece of angle to fit that. Well, I welded a piece of flat stock to it, and the angle is parallel to the face of the stone. Anyway, the angle of cut is adjustable, but constant once set, because it bolts together.
It is very fast to use, and easier than most other ways Ive tried.
I balance them using the screwdriver method...just put a round shaft thru the hole in the middle of the blade, if one end swings down, take more material off that side.
They say you should leave the blade a little blunt, but I sharpen it to almost a razor edge.
I do NOT like brown tips on my lawn from dull mower blades! Anyway, they seem to me to last longer that way anyway (sharpness), and cut things instead of just breaking them and sending them flying (like sticks).
The only other tip Id have is to keep an extra set of blades on hand and keep them sharp. I sharpen mine at least once every two months...and Ive had the same blades for about 7 years now. They look like they will last forever.
And, if you are short on time and want sharp blades, just swap them, and sharpen the old ones at your leisure. |
Bill Garrett
Member
Username: Billycarte
VA
Registered: 9-2006
Post Number: 455
| | Posted on Thursday, April 30, 2009 - 12:47 pm: |
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Mike,
I take them over to the local mower shop three sets at a time, and they sharpen them on a rotary blade grinder. This also maintains the radius at the inner most part of the cutting area where it transitions back into the blade. I use the JD high lift blades on my 420 and 430. These blades have over 7 inches of cutting area on each end. They charge me $27 for 9 blades including balancing. On the rare occasion when I feel inclined to sharpen a set by hand, I use a 16" mill bastard file, and then use a hack saw blade clamped in the vise to balance them. I sharpen the radius area with a coarse cross cut round file. The blunt edge is to keep the blade from being prone to chipping if you hit something hard like a stick, acorn, hickory nut, small rock, etc. Unless your lawn is pretty free of debris I would not sharpen to a knife edge.
One good point of reference would be to buy a new spare set of blades from JD and check the cutting edge to see how blunt or non blunt they come off the assembly line.
Besides the only way you can file a lawn mover blade and drink beer at the same time is if some one else is doing the sharpening! |
Jess Hansen
Member
Username: 5020
GA
Registered: 7-2004
Post Number: 347
| | Posted on Friday, May 01, 2009 - 7:10 am: |
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I use my belt sander. It works fast and has a large flat surface to keep the cutting edge uniform. I have used hand grinders, bench grinders and the old hand file and I believe the next best method is the hand file. Jess |
Jim Briney
Member
Username: Lodogg2221
IN
Registered: 1-2006
Post Number: 3105
| | Posted on Friday, May 01, 2009 - 9:19 am: |
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Jess, thats a heck of an idea.
What grit do you run on it? |
Jim Dimmerling
Member
Username: Jdodad1
Ohio
Registered: 11-2003
Post Number: 1257
| | Posted on Friday, May 01, 2009 - 9:28 am: |
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I get out my trusty 5" body grinder..............and go at it. We ARE cutting grass here, not finger nails.....lol.
I have tried balancing the blades and can't find any difference from a new set to a worn out set that were never balanced. That's using the methods described above.
A 5" body grinder, for those that don't know requires a big air compressor, uses a 5" 36 grit grinding disc, and is used in auto body shops every day.
I use it for all my blade sharpening, my sickle bars (Haban and New Holland), my JD Disc MoCo with 10 knives, and my mower decks.
The Grass Farmer |
Jess Hansen
Member
Username: 5020
GA
Registered: 7-2004
Post Number: 348
| | Posted on Friday, May 01, 2009 - 9:49 am: |
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Jim,
Honestly, whatever is already on the sander. Some times it takes longer with finer grits but typically there is 80-150 grit on the sander. My sander is a bit of a "hog" so a smaller sander may take more time. I simply turn the sander on its top, lock the switch "on" and clean up the blade. I may lap the back side for a moment or two as well.
Thanks,
Jess |
Rick Bina
Member
Username: Rick_b
WI
Registered: 12-2007
Post Number: 7
| | Posted on Friday, May 01, 2009 - 11:43 am: |
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Jim- you may not notice a difference between balanced and unbalanced blades, but believe me, your spindle bearings do!  |
Don Corbin
Member
Username: Dwc4020
Pa
Registered: 3-2006
Post Number: 562
| | Posted on Friday, May 01, 2009 - 3:20 pm: |
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I use my 4.5" grinder. Chuck the blade in the vise and go to town. As mentioned earlier, a balanced blade will be easier on the spindle, but for how long? After you hit a stone, dirt or as they mow your yard, they will go out of balance. Now grant it they need to be close but hey, we aren't working on a rocket ship here either. |
Rick Bina
Member
Username: Rick_b
WI
Registered: 12-2007
Post Number: 8
| | Posted on Friday, May 01, 2009 - 11:00 pm: |
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Don- sharpening removes material (and weight), hitting an object merely reshapes it. The weight from centerline of the spindle is still the same. Cut quality may be affected, but balance, not so much. I've worked on precision rotating machinery for over 20 years, so I have a little experience here. |
Andre Blanchet
Member
Username: Ab318
QC
Registered: 1-2005
Post Number: 670
| | Posted on Friday, May 01, 2009 - 11:11 pm: |
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I used my benchtop belt sander last year. It was the first time for those blade since new.
But for this year I'm thinking of making an attachment to hold the blade to improve the accuracy.
With fix angle and an adjustment for the dept the blade will not need to be balanced.
I hope to have time to do it between my others project.
One problem with the belt sander, the radius must be done with something else.
Andre |
Mike Drew
Member
Username: Drew
WI
Registered: 4-2007
Post Number: 423
| | Posted on Saturday, May 02, 2009 - 5:42 am: |
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I bought a little balance at the hardware store. The base is flat with a pin going up. The top is bell shaped with round graduations to fit the center hole. It's quick, simple and about 4 bucks. They sell them by the mower parts usually. |
Don Corbin
Member
Username: Dwc4020
Pa
Registered: 3-2006
Post Number: 563
| | Posted on Saturday, May 02, 2009 - 5:56 am: |
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Rick,
I understand what you are saying. What I was refuring to was that, you need to get them "close" but even if they are balanced precisly, they won't stay perfectly balanced untill the next sharpening.
As far as the term "Rocket Ship", these machines aren't as precisly built as a space shuttle or a race car, so things can be alittle off of being perfect. |
Mike Duwe
Member
Username: Mikeduwe
Wi
Registered: 10-2006
Post Number: 2914
| | Posted on Monday, May 04, 2009 - 8:58 am: |
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Tons of different methods.
I decided not to sharpen them for the first cut since there were some nuts and sticks on the yard.
Chopped a small stone in half on the edge of the lot, so I guess its good I didnt sharpen them yet! |
joshua cronk
Member
Username: Jcronk69
ny
Registered: 7-2006
Post Number: 340
| | Posted on Monday, May 04, 2009 - 4:45 pm: |
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Mike, I usually mow once in the spring before I sharpen the blades. It seems like there is always a few rocks that the mower "finds" that weren't there last year! |
Mike Gault
Member
Username: Mike
Mo
Registered: 1-2005
Post Number: 1532
| | Posted on Monday, May 04, 2009 - 5:10 pm: |
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Even a caveman can do it! 
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Grant Beem
Member
Username: Deereman3
MO.
Registered: 7-2007
Post Number: 28
| | Posted on Monday, May 04, 2009 - 8:23 pm: |
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Mike G, does the grape jelly help find the low spots? I can't tell by the picture, is that a standard disc on your grinder or a "flapper" style disc? |
Mike Gault
Member
Username: Mike
Mo
Registered: 1-2005
Post Number: 1533
| | Posted on Tuesday, May 05, 2009 - 7:59 am: |
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Grant � the grape jelly contains anti-oxidants which keep the friction low thus creating less heat that harm the blade.
It�s a standard disc. |
stephen shiery
Member
Username: Sashiery
MO
Registered: 12-2006
Post Number: 718
| | Posted on Tuesday, May 05, 2009 - 11:52 am: |
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Grant, the Baltimore Orioles (the bird, not the baseball team) returned to Missouri last weekend. They like grape jelly, nectar, and oranges. You have to feed them separately from the hummingbird feeder to keep the hummingbird feeder available for hummingbirds. |
Grant Beem
Member
Username: Deereman3
MO.
Registered: 7-2007
Post Number: 29
| | Posted on Wednesday, May 06, 2009 - 10:57 am: |
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Stephen S, that explains why I saw Cal Ripkin in my backyard with a purple stain around his mouth.
Mike G, I'll have to try your method, I always use my bench grinder, cut too much off, make the tip glow red, & quench with an adult beverage. After I have 2 adult beverages the blades are cool enough to handle.
BTW, I have an ancient brass balance I use. A buddy of mine swears by the nail method.
Grant |
Mike Gault
Member
Username: Mike
Mo
Registered: 1-2005
Post Number: 1534
| | Posted on Wednesday, May 06, 2009 - 8:07 pm: |
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Grant - Use a torch after grinding & heat them up some more. Then you can have 3 or 4 beverages.  |
George B
Member
Username: Georgeb
Oh
Registered: 6-2007
Post Number: 458
| | Posted on Monday, May 11, 2009 - 9:37 am: |
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Here's what the JD 400 manual has to say about sharpening blades on the 60" deck:
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John McMurray
Member
Username: Jmcmurray
AB
Registered: 8-2007
Post Number: 6
| | Posted on Tuesday, June 09, 2009 - 7:29 am: |
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I don't have much choice but to hit a bunch of gravel and mole hills along my driveway. What I'd like to find is some blades that have a more room to wear. Brand new blades give me around 3/8 of an inch of material at the tip to sharpen before I hit the "wing". (top of the attached image) When the tip gets dulled to 1/8" thick at the tip it requires sharpening back 1/8" or more to get back to 1/64" at the leading edge. This only gives me 5 or 6 sharpenings before the bevel and the wing are touching.
It is such a waste of material to throw out blades after removing such a small amount of material. After all, it is really the tip that does most of the cutting and wear and should be the widest part. Instead, because of the wing, it is the narrowest.
I'd like to see someone come out with blades like the bottom half of this picture.
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Bill Wilhite
Member
Username: Bjfarms
Missouri
Registered: 5-2009
Post Number: 3
| | Posted on Tuesday, June 09, 2009 - 4:00 pm: |
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I also use a belt sander with what ever grit I have on it at the time. I was told by an old timer to drive a 16 penny nail in a stud in the shop wall and hang the blade on the nail. Which ever direction it leans towards you take more off of that side to balance the blade. |
Georg Heck
Member
Username: Montanany
NY
Registered: 3-2004
Post Number: 1303
| | Posted on Wednesday, June 10, 2009 - 6:33 am: |
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I picked up a metal stationary belt grinder a few years ago and just started using it. Really like it, but I do agree with:
Jim - "We ARE cutting grass here, not finger nails" |
Mark A. Spoon
Member
Username: Spoonman
NY
Registered: 6-2009
Post Number: 26
| | Posted on Thursday, June 11, 2009 - 5:01 pm: |
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Sand blasted mine then just used my die grinder since the blades which I bought new at my jd dealer are junk because my property is ummmm like not very flat or easy to keep the rock garbage and tree limbs out of. i need a new set think like $40 or somethin..I always try to balance mine but the crazy vibrations comming from my deck tell me I dont do a very good job at it,prolly gonna need new spindles too |
John McMurray
Member
Username: Jmcmurray
AB
Registered: 8-2007
Post Number: 10
| | Posted on Monday, June 15, 2009 - 2:14 pm: |
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I took a picture of the new JD blades before I put them on. It is actually worse than I thought because of the low angle of the cutting edge. It takes only a few sharpenings to hit the "wing".
Has anyone seen blades with a greater amount of wear surface? |
guy peterson
Member
Username: Darkstargp
CT
Registered: 1-2005
Post Number: 78
| | Posted on Monday, June 15, 2009 - 7:30 pm: |
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Done so to ensure you buy a new set - capitalism at its best. Considering their tractors last forever, JD needs a source of income. |
Tim N.
Member
Username: Tim_jd216
VA
Registered: 8-2004
Post Number: 1043
| | Posted on Wednesday, June 17, 2009 - 12:58 pm: |
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John,
Have you taken a look at gator blade?
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