Mowing Which rotary cutter

Freddieboy · Mar 15, 2011

Hi all,
Love this site and now time to ask for advice. I have a 2920 and I am in the market for a rotary cutter. Depending on which dealer I speak with I get conflicting info concerning whether the 2920 can handle a 5' cutter. Seems most 5 footers are only 50 -60 lbs over a 4' and should be OK, but I'm a newbie and need a little hand holding on this one from the experienced.

Thx in advance.

TripleR · Mar 15, 2011

You will have to take into consideration whether it is a light, medium or heavy duty cutter. I use a RCR1548 on my BX2660 and can't imagine you having trouble with a five foot unit on a B2920.

There is a significant weight increase however going from the RCR15 to the RCR18, so that would be a consideration.

I am sure someone who actually owns a B can give you more specifics as there are several on here.

Good luck.

KU Gator · Mar 15, 2011

I have had a B2920 for about 3 years. When I was in the market for a rotary mower, my dealer suggested a 5' one. I trailered the tractor to the dealer and hooked up a 5' Bush Hog Squeeler and tried it and it seemed ok. They had a lighter duty Razorback, but I felt like I wanted the heavier gear box and the heavier over all build, so went with the Squeeler.

I keep the FEL on when mowing with it to counter balance the weight, especially when I have it off the ground transporting it. Other than when we mowed some of the property that had not been mowed in a long time and last year when I got behind in the mowing and got an infestation of Lespedeza weed, I have no problem with it going through the grass. I haven't really used it to cut much true brush.

My dealer caries primarily Bush Hog so that is what I went with and I really did not want to go down to a 48". Had I have went with Land Pride, I think they make a 54" that I would have probably considered.

When I engage the PTO, I have the RPM's low and let the clutch out. There is initially a lot of vibration as the blades spin out and once that settle down, I bring up the RPM and it is pretty smooth.

WV Tractorman · Mar 15, 2011

I run a BushHog 5 ' Squealer behind my L2800 with no problem. I don't have a Endloader yet, just front weights and have no problems on the hills here in West Virginia. I'm glad I took my dealers advise and went with the Squealer over the lighter model.

RoyJackson · Mar 15, 2011

My cutter, a 10 year old Land Pride 5' unit, was purchased for a small Deere (17 PTO HP). I thought it would be too big. The dealer (who was also a Kubota dealer) said they sold a fair number of the same cutter for the B7500 Kubotas which was less the 2000 lbs and about the same PTO HP. The dealer was right...that cutter worked fine.
If all your mowing is heavy brush, you might want the 4' cutter. But if it's a mix of thick stuff and lighter stuff, like mine was at the time, go with the 5' cutter and make partial width passes.

Marveltone · Mar 15, 2011

At 1554 lbs, the 2920 is a pretty light tractor. A heavy RC can swing the tractor around if you get too rambunctious. Woods makes a 54" RC with your choice of shear bolt or slip clutch. I'm loving mine! For a small fee, they'll even color match your 'Bota. :thumbsup:

Joe

RoyJackson · Mar 15, 2011

Marveltone said:
At 1554 lbs, the 2920 is a pretty light tractor. A heavy RC can swing the tractor around if you get too rambunctious. Woods makes a 54" RC with your choice of shear bolt or slip clutch. I'm loving mine! For a small fee, they'll even color match your 'Bota. :thumbsup:

Joe

The B7500 was about 150 lbs (plus or minus) less weight. If they can handle a 5', 600 lb cutter, so can the heavier B2920. I think you'll find the weights quoted for the Kubotas do not include the loader (and if it's the shipping weight, the wheels/tires aren't include either.
My old Deere 670 went just under 2000 lbs (sans loader) and did fine, even when transporting the cutter.
However, Joe, you do make a good point about not swinging that cutter around. I never raise the cutter to full height of the 3PH and just towed it (unhooking the top link and using the tail wheel). Even then, it was slow and careful transporting.

leonz · Mar 15, 2011

Freddieboy said:
Hi all,
Love this site and now time to ask for advice. I have a 2920 and I am in the market for a rotary cutter. Depending on which dealer I speak with I get conflicting info concerning whether the 2920 can handle a 5' cutter. Seems most 5 footers are only 50 -60 lbs over a 4' and should be OK, but I'm a newbie and need a little hand holding on this one from the experienced.

Thx in advance.

With regard to your brush mowing: have you examined a flail mower for the work? A four foot flail mower will not tax your prime mover and will not create a case of the "tail wagging the dog" scenario as the flailmower is much shorter in length than any rotary cutter.

The other thing to keep in mind is only half of the cutting width is used at any time versus the full width of the flail mower cutting at all times.

Marveltone · Mar 15, 2011

leonz said:
With regard to your brush mowing: have you examined a flail mower for the work? A four foot flail mower will not tax your prime mover and will not create a case of the "tail wagging the dog" scenario as the flailmower is much shrter in length than any rotary cutter.

The other thing to keep in mind is only half of the cutting width is used at any time versus the full width of the flail mower cutting at all times.

Wouldn't it be more accurate to say only half the cutting potential is being used at any time? Width is left to right, and all the width is being used on a rotary cutter, but only half the length, as the front cuts and the rear floats and chops up some of the vegetation.

Of course, I can use the same argument for flails... Only the blades on the bottom of the drum are cutting. That leaves only 1/4 of the drum doing any actual work. The rest of the knives are making their way around the top and are wasted motion!

Joe

KU Gator · Mar 16, 2011

Beyond reading Leonz's contributions on flail mowers, I can say I know nothing about them. But as he says, even given the same weight, it would not be carried nearly as far back with a flail compared to a rotary. This would also help if you trailer the tractor and mower. On a 16' trailer, the rear wheel of my mower is sticking off the trailer.

But the next issue would require some input from Leonz. If the flail mower glides on the ground on skids when mowing and does not require the 3 pt hitch to hold it up, this would be an advantage with the B2920. Because the B2920 has the 1/4" valve which will not hold an implement at a specific height for a long time. Therefore while you mow with a rotary mower, you have to remember to bump the hitch back up every 10 minutes or so or you will have the front of the mower dragging on the ground. So please provide input on this Leonz.

leonz · Mar 16, 2011

Marveltone said:
Wouldn't it be more accurate to say only half the cutting potential is being used at any time? Width is left to right, and all the width is being used on a rotary cutter, but only half the length, as the front cuts and the rear floats and chops up some of the vegetation.

Of course, I can use the same argument for flails... Only the blades on the bottom of the drum are cutting. That leaves only 1/4 of the drum doing any actual work. The rest of the knives are making their way around the top and are wasted motion!

Joe

A little bit of a flaw here:

EDIT: A rotary cutter is a two sided piece of paper wher you can only use one side of the paper at one time.

EDIT: A disc mower would be a bit more productive but as you are cutting brush you are using one of two or four blades at one time

In our case the flail mower is 48 inches wide

The actual cutting width is 48 inches

The grass slicers are paired on each hanger except for the end hangers where one grass slicer is hung.

The number of grass slicers is 18 or 20 per row

Each grass slicer has 1.5 inches of ground knive edge

3 inches of knive edge per pair

72 hangers with 3 inches of cutting surface gives us 216 inches of cutting/slicing edge operating at all times.

This does not include the new cutting edge on the opposite side of the individual knive that is unused.

SO..................................................................................................

leonz · Mar 16, 2011

KU Gator said:
Beyond reading Leonz's contributions on flail mowers, I can say I know nothing about them.

But as he says, even given the same weight, it would not be carried nearly as far back with a flail compared to a rotary.

This would also help if you trailer the tractor and mower. On a 16' trailer, the rear wheel of my mower is sticking off the trailer.

But the next issue would require some input from Leonz.

If the flail mower glides on the ground on skids when mowing and does not require the 3 pt hitch to hold it up, this would be an advantage with the B2920.

Because the B2920 has the 1/4" valve which will not hold an implement at a specific height for a long time.

Therefore while you mow with a rotary mower, you have to remember to bump the hitch back up every 10 minutes or so or you will have the front of the mower dragging on the ground. So please provide input on this Leonz.

Yes, you are right about this KU gator; you want the top link to be loose and have slack to follow the ground contour more easily for the end user.

The rear roller of the flail mower allows for full contact with the ground at all times when in float to reduce scalping to an absolute minimum.

The mowers width and close in coupling spacing adds to the stability of the mower and tractor as the mower is always hugging the ground courtesy of gravity.

The rear roller is always a stabiliser for the tractor it is paired with.

Hope this helps everyone.

RoyJackson · Mar 16, 2011

leonz said:
The other thing to keep in mind is only half of the cutting width is used at any time ...

Theoretically, you're correct.
However, considering the blade speed of a cutter, I think you're picking nits.

I have yet to make a pass (with a cutter) where I saw half the brush still standing.

Cutters are pretty simple and don't require much maintenance other then greasing and an occasional dressing of the blades with a grinder.
Since a flail mower (and to be fair, I don't own one and have never used one) has a higher initial cost, requires more maintenance and a lot more blades to sharpen, I can't see much advantage unless you're in an area in which the occasional thrown object would be a problem (and cutters surely can throw objects!)

TripleR · Mar 16, 2011

Lots of things to consider when comparing a rotary cutter v flail. Leonz has given me a lot of good information on flail mowers, but rotary cutters work best for us and the added length gives us needed reach on pond levies, under trees and over ditches etc. Our farms are only four to six miles apart, so we drive rather than haul.

For some, a flail mower will be just the ticket.

Tom_H · Mar 16, 2011

Tripple R is right. Light, medium, and heavy duty models are designed to cut different materials. This is not related to the size of the unit. I have a 40" heavy duty Gearmore that will cut patches of sapplings almost 3" thick.

Flail mowers also come in light, medium and heavy duty. Light duty have knives to cut grass. Heavy have hammers to break heavy stuff. Flails cost more, have many more parts, and are much more maintenance. The advantage of a flail is in use where pedestrians are present. Rotary cutters will launch big rocks like missles. Flails do not. Flails are needed where there are bystanders. If you are not cutting where people are standing around, you do not need a flail.

Freddieboy · Mar 16, 2011

Thanks everyone...I have decided on the Woods 54" as a compromise. Should fit just right.

KU Gator · Mar 17, 2011

I think that is a great choice. I never really looked at Woods, but that is because both times that I went to the local dealer that has them I was told the sales guys are at lunch, you can take a brochure if you want. They may still be at lunch as far as I know. But everyone that has Woods seem to be happy with them.

Tom_H · Mar 17, 2011

Freddieboy said:
Thanks everyone...I have decided on the Woods 54" as a compromise. Should fit just right.

BUT is the unit light duty, medium duty, or heavy duty, AND does that match the material that you want to cut?

If you are getting a light duty unit and you want to cut clusters of 3" sapplings, it will not work. If you only plan to cut tall grasses, light duty is fine, however. To cut sapplings, you need a heavy duty unit, no matter what the size. Width is unrelated to whether a unit is light, medium, or heavy duty.

What are you planning to cut? Is the unit you are looking at light duty, medium duty, or heavy duty?

fredhargis · Mar 17, 2011

Freddieboy said:
Thanks everyone...I have decided on the Woods 54" as a compromise. Should fit just right.

I'm looking for a rotary cutter this year for my 2920. I keep thinking I'll find a used one but that hasn't worked out so well at this point. But the manual calls for it to handle a 60" cutter...if I buy new it'll be a 60" medium duty. I'm thinking I'll use chains to hold it's position but I'll wait and see. This is all new to me.