Rotary Cutter Rotary cutters vs. RFMs

[JayC]

I'm just curious what is the difference in the quality of cut with a rear-mount rotary cutter versus that of a rear-mount finish mower? To tell you the truth, I don't know much about tractors, but ever since I found this site, I have learned a LOT of useful info. /forums/images/graemlins/smile.gif

 

[TimSullivan]

We have been cutting an old orchard that had been let go to brush for several years. The grass has grow in well this year with all the rain and it is about time to buy that finish mower.

The project started buy using a five foot bush hog behind a 4300 Deere to cut down the brush and nasty rose bushes. Some of the rose bushes were too big for the cutter and had to be pulled out. All in all the cutter did a great job of clearing the land. After the stubble of the brush was gone the grass did not look bad at all. The bush hog is still our main cutter but as the grass improves we cut more and more with a lawn tractor. It just looks better.

Our plan is to buy a 6 foot RFM to use on the large areas and use the bush hog to cut the rough areas in and around the woods. The finish mowers just do a nicer looking job as the grass improves. The lawn looks OK after the bush hog cuts it but it does tear more than cut..

 

[jcollins]

Basically a RFM (Rear Finish Mower) is a lawn mower behind a tractor. It is designed to cut only grass and really lawn grass. It uses a PTO driven gear box that has a pulley below it. The pully usually has a belt on it that drives 3 or more lawnmower type blades. A bush hog (brush hog) uses a PTO shaft to the gear box and the gear box has a output shaft that drives your stump jumper. Attached to the stump jumper are usaually two free swinging blades that chop at the material rather than cutting the material as a RFM does. The RFM will give a very nice quality cut while the brush hog tends to tear at the grass. Brush Hogs are normally cheaper to purchase than the RFMs though. Hope this helps.

 

[WVBill]

</font><font color="blue" class="small">( ... A bush hog (brush hog) uses a PTO shaft to the gear box and the gear box has a output shaft that <font color="red"> drives your stump jumper. Attached to the stump jumper </font>are usaually two free swinging blades ...)</font>

Could someone explain what a "stump jumper" is? I've seen the term many times and assumed it was some kind of wheel/guard that made the rotary mower ride up over stumps. What would be a stump jumper that's driven by the output shaft?

 

[shady1701]

Depends on what you plan on doing with it and the effect you want.

If you just want to cut grass in a rough or have hidden objects you'd go with rough cut mower.. I've seen alot of the good woods/jd cutters do a realy good job at cut quality almost rivaling a finishing mower i'd say. If you plan on mowing it high over 3" i'd go with rough cutter.
Generaly from $500-1400
The finishing mowers are just that for grass only with no objects and generaly can only mow grass about 4" high or so.

They have 3 spindles and can be damaged easily if you hit a good size rock, tree or anything else a lawn mower wouldn't go over. Blades run about $10 a pop x3 and can be fitted with hi-lift and produce a very smooth area which is idea for like golf courses, walking or kids playing.
prices are generaly $900-1200 some ultra high dollar befrco and others top $2K

Another good choice would be a flail mower basicaly a rototiller with a set of cutting knives on it in the shape of a Y said to be pretty much between the 2..
FLAIL MOWER EXAMPLES

The stump jumper my understanding is it's the round blade holder in the center of the rotary cutter when you hit a stump,rock or anything else that doesn't move the blades fold in and smooth with the round disc that is spinning. it the simply jumps over the object since the disc is rounded off keeping the spindle/blade assembly from getting caught up on object and ripping the spindle out like on a RFM. correct me if i'm wrong..

 

[pruntyc]

Well, the one who said the rotary cutter is not a cut, but that they chop and tear the grass. Well that will be true if you don't keep the blades sharp. Just like if you don't keep the blades sharp on a lawn tractor. They will do the same thing. but if you keep the blades sharp on the rotary cutter, they do a very good job. Maybe not a golf park look, but still very good. So if you are looking at keeping a large area looking nice, but don't need it to look perfect the rotary cutter is the way to go, but like the man said, you don't want any trash out there with a finish mower. Where that won't bother a rotary cutter, except you may need to touch up the blades to make them a little sharper after you cut up some heavy wood or hit a rock or two.

 

[GSS]

I just sold my RFM b/c I got a brush hog. The hog cuts the grass decently, but not as cleanly as the RFM. It will also not follow the more sublte curves in the land like the RFM with 4 wheels will. The hog blades seem to hit the ground a lot more on the more uneven terrain too. The hog will also leave more obvious "windrows" of cut grass. I do tend to wait longer to cut these areas though, so it might not be as obvious if you cut it when you cut the rest of your lawn.

The hog cuts the little bit of open grassy areas that we have well enough to justify selling the RFM.

- Gerald

 

[LuvMy670]

I am using a rotary cutter in my pasture and it really leaves some gouges in some of the areas that are not flat. If you have a really flat area, then the rotary would be OK. I mow a pasture and I liked the rotary, but then out of laziness (I have to mow around the fence row with a lawn tractor to get closer cut) I went ahead and used the lawn tractor for the whole job. (Oh yeah, I keep that pretty clear of anything detrimental to mowers as I had to mow it with a lawn mower for 16 years before I got my "real tractor and bush hog".)

Well, guess what, I want a RFM now because I definitely like the look of the manicured pasture rather than the rough cut look. I can use the rotary to do the bulk of the heavy cutting and then finish it with the RFM.

I have a mini farm (ha ha, 3.5 acres) so either way, it doesn't take long to do the field. But horses do NOT eat grass in a nice manicured pattern and that long stuff grows FAST and thick.

 

[djradz]

Gerald, outfit your brush hog with check chains. You'll get a cut that's close to a RFM as far as level with no more gouging due to uneven terrain. They won't help however with the windrowing.

 

[shady1701]

chains on the toplink i think what you're suggesting? will kick up and crush you..