Rotary Cutter Sharpening the blades

[LouNY]

My old Woods brand has never been sharpened, it's hit an unknown number of rocks and other debris.
The blades have a rounded over profile they work good for what she is used for brush and large course weeds.
In pastures and fence lines stone walls and such, we have many other mowers suited for grasses from sickle bars to haybines and discbines even a flail.

 

[JasperFrank]

At the start of the season I use my FEL to pick up and completely flip the Brush Hog on to its back. Then use an angle grinder to put a LIGHT edge to the blades. Then check the tightness to all the nuts and bolts and straighten up the skirts. To me, this seems the safest way of doing it and I can inspect everything clearly.
I have heard from many other people that blade sharpening was not necessary, if your use is to take out brush. But at the start of the season, sometimes the grass areas are still wet, and have gotten higher than the lawn tractor mower can deal with. The sharpened blades do a much better job on the tall, wet grass than if they are blunt edged.

 

[Tony H]

I sharpen mine every few years. Just an angle grinder works. I like to CUT not TEAR, what I'm going thru. It makes it easier on the PTO. Angle grinder works since balancing the blades aren't a real issue

 

[ROUSTABOUT]

I've had them sharpened down old blades. Welded a piece of road grader blade on them and were like new again. Hung them on cotton scales to get them weighing the same for balance.

 

[beenthere]

I have a 6" rotary cutter I have used for years to clear some old pasture. Like many of us I have hit a few rocks and some branches along the way. All of that being said the "sharp side" of the blades now have a bullnose profile. I have never sharpened the blades.

I went by a local shop and asked about sharpening the blades. The first fellow I spoke with looked at me like I was crazy; he said he'd never heard of sharpening the blades on a rotary cutter. The second fellow interrupted him and said they did sharpen the blades. Since I have never sharpened them they still have plenty of width.

Have you ever sharpened your bush hog blades?

How do you know when they are not worth sharpening?


My plan is to by an extra set of blades to replace my used blades. I will then have the used blades sharpened and keep as extras. Any advice?

No problem with you spending your money on new blades. But not necessary, just that it will make you feel good.
If using the rotary to cut brush, your present blades will likely do that very well. If trying to use the rotary mower to manicure to a lawn-like finish, then the rotary mower is the wrong attachment, IMO.
As many posts suggest, touch up any rough spots with an angle grinder.
A photo of your blades would be very helpful to zero in on better suggestions for you.

 

[10backacres]

If memory serves me you need a troque multiplier to remove the blade bolts. I haven't sharpened my very abused 430. I just use the seppi flail as long as there's nothing really large in the brush

 

[ROUSTABOUT]

Oh no, that was back 40+ years ago when I was a teen! I remember reading it and showing my dad it could cut hay.

I did find this that may help you, Hercules Service Parts - Agricultural equipment repair located in Minden, Louisiana - Your Rotary Mower Experts!

Yep some cutters you could un bolt one side and take it off to cut hay.

 

[ROUSTABOUT]

If memory serves me you need a troque multiplier to remove the blade bolts. I haven't sharpened my very abused 430. I just use the seppi flail as long as there's nothing really large in the brush

I use a 3/4 or 1" impact mostly. There's always the cheater pipe for when using hand tools. Had a fella bring one here needing help getting the blades off. They were left hand threaded bolts. Got to watch out for that too.

 

[mjonesnh]

Have 2 sets of blades. Just changed out dull set on cutter for sharpened set. Will sharpen dull set before end of next season and repeat next fall. Using Makita 3/4 battery impact on nuts. About a 30 minute job for changeout.

 

[Lineman North Florida]

A rotary cutter with a higher blade tip speed will also cut better, as well as getting RPM's up on the tractor so the PTO can get that blade tip speed up where it should be for optimal cutting. I have seen some rotary cutters with higher blade tip speed outfitted with lift type blades that were sharpened give a really good looking manicured type cut on a field, not finish mower look, but close.

 

[Sawyer Rob]

With my Woods cutters, you don't need a huge socket or 3/4 impact to get the blades off, they have a design that doesn't require it!

SR

 

[Surshot]

Mowers, mulpitle spindles on the deck, requires sharpening, a bush hog, a single spindle, on the deck, you do not sharpen, it is designed to smash not cut cleanly.
My Bush Hog, bush hog which has a very high blade tip speed, will mow Pensacola Bahia grass, if it is cut low, at 1,500 rpm. Without the rounded blade edge being sharpened.

 

[Lineman North Florida]

Mowers, mulpitle spindles on the deck, requires sharpening, a bush hog, a single spindle, on the deck, you do not sharpen, it is designed to smash not cut cleanly.
My Bush Hog, bush hog which has a very high blade tip speed, will mow Pensacola Bahia grass, if it is cut low, at 1,500 rpm. Without the rounded blade edge being sharpened.

First time I have ever heard that.

 

[mjonesnh]

Mowers, mulpitle spindles on the deck, requires sharpening, a bush hog, a single spindle, on the deck, you do not sharpen, it is designed to smash not cut cleanly.
My Bush Hog, bush hog which has a very high blade tip speed, will mow Pensacola Bahia grass, if it is cut low, at 1,500 rpm. Without the rounded blade edge being sharpened.

Well, my mower is a single spindle unit and it gets sharpened blades every year. Cuts mostly grass and weeds with some saplings and sometimes some big rocks. Sharp blades every year works quite well for my needs

 

[Gator6x4]

The nut holding the blades on a Rotary Cutter or Bush Hog are usually torqued to 600-700 foot pounds. Most do not have the tools to remove the blades so they either do not sharpen or sharpen the blade mounted on the Bush Hog. This is hard to do. The blade(s) are mounted to the stump jumper and are by design meant to be free moving. The weight of the blade and centrifugal force is what holds the blade out for cutting. Being able to move also allows the blade to deflect inward and away from a struck solid object to prevent stress loading and destruction of the gear box on the Bush Hog or drive line damage on the tractor.

A good Bush Hog video to watch. Also please note the object deflection or knock down chains on the Bush Hog in the video. Many a Farmer has done some big time damage by throwing a huge rock against something or through something.

 

[big bubba]

would never consider crawling under or attempt to sharpen cutter knives attached. too easy for a face full of grinder wheel. get a good impact wrench, a powerful compressor that will handle the load (usually 8 or more cfm @ 90 psi, the more the better), use a cheater bar to finish up the torque

note that most of the actual cutting occurs within the 1st few inches of the blade, so even if you don't sharpen or hit much stuff, the ends will become rounded through use & lose the effective cut. same true on lawnmower blades

 

[marhar]

I remove mine on the RC2048 every spring and sharpen on a rotary grinder. Do not actually sharpen, just reshape to get worst stuff smoothed out. Never have replaced blades. Run for a while with trail wheel off and then retorque with 6 ft piece of pipe.

I plan on doing what you are doing. I like the way you explained "reshaping" the blades. Half of my mowing grass around a barn and an acre food plot the other half is using the rotary cutter to clean rough area with saplings etc. .

I will buy another set of blades and install in the spring. The set I take off I will "reshape".

 

[Sawyer Rob]

The nut holding the blades on a Rotary Cutter or Bush Hog are usually torqued to 600-700 foot pounds. Most do not have the tools to remove the blades so they either do not sharpen or sharpen the blade mounted on the Bush Hog. This is hard to do. The blade(s) are mounted to the stump jumper and are by design meant to be free moving.

This is totally WRONG on my Woods cutters, first off, you don't need 6 or 700 pounds of torque on my Woods rotary cutters and the blades are NOT attached to the stump jumper!

The blades are held on with "keepers" that are held in place with a bolt that can be removed from the top, with a common 1/2" drive socket.

SR

 

[Gator6x4]

This is totally WRONG on my Woods cutters, first off, you don't need 6 or 700 pounds of torque on my Woods rotary cutters and the blades are NOT attached to the stump jumper!

The blades are held on with "keepers" that are held in place with a bolt that can be removed from the top, with a common 1/2" drive socket.

SR

Did you watch the video? I have a 6 foot Woods that the blades look like and attach like in the Bush Hog in the video.

Same bolt, etc. The difference being on the Woods the access hole to loosen the nut is rectangular instead of round.

I also understand the newer Woods have a different bolt blade attachment.

 

[Williy]

This is for the Wood's BB60.60 BB72.60 BB84.60

1.Gearbox
2.Crossbar assembly
3.Washer
4.Castle Nut
5.Cotter Pin
6.Blade
7.1-1/2 Blade Pin
8.Shim 20 GA
9.Shim 18 GA
10.Shim 7 GA
11.Keyhole Plate
B12.lade Pin Lock Clip
13.1/2 NC Hex Head Cap Screw

willy