Rotary Cutter Shorten blades on rotary cutter to match tractor HP

[birdman13261]

I have the JD 1025r and it is 18hp at the PTO and I need a rotary cutter to clear some woods with multiflora rose and other tall weeds and briars. The dealer says to use a 48" mower abd they are in stock and look real pretty, but I want a cheap used one and I have yet to see one reasonably priced. So here is what I am thinking.....can I use 48" blades on a 60" (5') 3pt mower at 540 RPM? Either shorten (cut or grind) the 5' swing blades or buy 4'?

First post, thanks for any advice!

 

[amaxwell]

I have the JD 1025r and it is 18hp at the PTO and I need a rotary cutter to clear some woods with multiflora rose and other tall weeds and briars. The dealer says to use a 48" mower abd they are in stock and look real pretty, but I want a cheap used one and I have yet to see one reasonably priced. So here is what I am thinking.....can I use 48" blades on a 60" (5') 3pt mower at 540 RPM? Either shorten (cut or grind) the 5' swing blades or buy 4'?

First post, thanks for any advice!

I used a 5' cutter with my ford 1300 (13 pto HP) for several years . I just cut a narrower swath each time around the field. Now I use the same cutter with a 24HP tractor. As long as the tractor can handle the weight of the larger cutter you should be ok.

 

[Samuellm]

All the mowers I have worked on take the same leght blades it is the boss in the center that is differant have a look and see it is the same for your ones. I see no reason why not unless it is too heavy for the 3ptl

 

[birdman13261]

Thanks guys, I think I will check out 5 footer and see if I can mow with that and maybe use shorter blades for the thick briers. I can't take small passes since I will likely be backing over them.

 

[LD1]

I'd try it with the 5' first. 18hp at the PTO is probably similar to what an old wore out 9n/2n ford would be putting out. Go slow, and raise the cutter, back over, then slowly lower.

If that dont work, your best bet is to sell and buy a 4' cutter. By chopping the blades down, you really loose blade tip speed. Would still chew up the briars though, but would probably suck for grass and weeds once you get the briars under control.

Oh, and welcome neighbor. Centerburg is just a few minutes south of me, and I happen to pass through there quite often, usually on the way to the golf course.

 

[Capricious]

Not endorsing any particular supplier, but you can find a lot of dimensions for cutter blades here:

http://www.powellequipmentparts.com/rotary-cutter-finish-mower-parts_opt.pdf

 

[jeff9366]

Do not fool with design parameters for implements.

Instead, sharpen the blades on your used rotary cutter, then take a narrower bite.

Bayer Weed and Stump Killer herbicide kills Multiflora rose and other briars with one or two applications. Roundup requires five or more applications to kill same.

 

[gwdixon]

The momentum of the blades (due to weight) and their rotational speed (tip speed) is what does the cutting. If the travel is too fast and/or the foliage too heavy then the blades will swing out of the way and cutting width will be reduced. The blades effectively shorten themselves automatically.

With shorter blades on a larger machine the lighter weight of the blades would reduce momentum and tip speed. It would actually be harder to cut with shorter blades. This would be compounded if the gearbox is designed for a certain length blade and a shorter one is installed.

LD1 has pretty much addressed the issue well.

So in summary, I'd buy the larger mower and sharpen the blades to reduce drag (a controversial subject). Then I'd watch the engine RPM as it relates to the ground travel speed over the mowing area. Less bite, higher mower setting, more overlap, slower speed would be strategies that could be options (credits to LD1).

Edit: Credits to Jeff also, we matched posts.

 

[flusher]

Do not fool with design parameters for implements.

Instead, sharpen the blades on your used rotary cutter, then take a narrower cut.

Bayer Weed and Stump Killer herbicide kills Multiflora rose and other briars with one or two applications. Roundup requires five or more applications to kill same.

Right on. Sharpen the blades. Since I don't have any brush to mow, just weeds, the blades on my 6-ft Hawkline brush hog are sharpened to the same edge radius I use on my riding mower.

 

[Mendonsy]

Are you talking about using a mower (fixed blades) or a bush hog (swivel blades)???
That will make a big difference!! If you use a bush hog as gwdixon suggests you won't have a problem. A mower with fixed blades will not work well at all on heavy brush.

 

[Capricious]

I think I would just keep looking for a 4 footer, and be ready to jump on it when you come across one.

I was looking for a 4 footer, when what I really wanted was a 42", because while there is about one 4 footer advertised for every (30) or so 5 footers, there is also about one 42" advertised for every (30) 4 footers. At least that's the way it is around here. Even a new 42" is special order, plus shipping, because no dealer will stock them.

Then someone advertised a used 42", first 42 I had seen for sale, and I jumped on it. 80 mph up the highway to be sure I got there before someone else, empty trailer bouncing clear off the road at the expansion joints.

 

[birdman13261]

Are you talking about using a mower (fixed blades) or a bush hog (swivel blades)???
That will make a big difference!! If you use a bush hog as gwdixon suggests you won't have a problem. A mower with fixed blades will not work well at all on heavy brush.

I plan to use a bush hog style cutter with swing blades.

 

[LD1]

I plan to use a bush hog style cutter with swing blades.

Do do you already have a 5' cutter? Check craigslist. There are a few 4' and 1 4-1/2' cutters on there. I check both mansfield and columbus. But remember you never know how it will be posted. I search it 5 ways:
bushhog
bush hog
brushhog
brush hog
rotary cutter

If you have a 5' cutter, what is it? make/model? heavy duty or lighter? It does make a difference in how well a small machine can handle it.

 

[Capricious]

bushhog
bush hog
brushhog
brush hog
rotary cutter

To which I would add, "shredder".

 

[LD1]

To which I would add, "shredder".

just tried that one.

Nothing in my area. Just wood chippers and office paper shredders:confused3:

 

[Capricious]

just tried that one.

Nothing in my area. Just wood chippers and office paper shredders:confused3:

I have seen these things called shredders on a couple of occasions. I used to search under all the names you listed,
along with "shredder".


https://austin.craigslist.org/grq/4593049466.html


https://austin.craigslist.org/grq/4611066104.html

 

[buickanddeere]

You are looking for problems where they don't exist. The concern with be more rotary cutter weight than what the tractor can carry.
Use the proper tool for the job.
Going to shorter blades with lower the tip speed and reduce cutting efficiency .
As preciously stated. Gear down to creeper and take a part width cut.

 

[GolfAddict]

Right on. Sharpen the blades. Since I don't have any brush to mow, just weeds, the blades on my 6-ft Hawkline brush hog are sharpened to the same edge radius I use on my riding mower.

If you are not cutting any brush, saplings, etc., then sharpening blades can help as mentioned. However, be aware that the blades on brush hogs are intentionally not sharp like lawn mower blades, as often a brush hog is also cutting brush.

The "dull" blades will leave the small stumps shattered, rather than a nice clean cut off. A clean cut stump can puncture right through a tire when going through on future cuttings...

 

[birdman13261]

No I don't have a BH yet, hope to get one soon and get to cutting before deer season.

Thanks for CL tips, I will check them out now. Also I use the statewide search site Search Craigslist by state and More., and the cPro CL app.