Rotary Cutter acres per hour w/ 48" rotary cutter

[hazmat]

acres per hour w/ 48\" rotary cutter

There are plenty of charts on how to compute acres per hour for a given mowing width. exmark productivity tables

The key input is speed. What's a reasonable assumption for cutting a field (grass)? My parents are considering purchasing a "farm" in Maine to run their dogs on. I'm hoping my old man doesn't want to buy himself a tractor, but would like to subsidize a trailer & rotary cutter for me. Just wondering how big a field I could cut in a weekend.

 

[njrqs]

Re: acres per hour w/ 48\" rotary cutter

Just been doing some slashing as we finally had some rain /forums/images/graemlins/grin.gif

I have a 4' or 48" slasher (rotary cutter to you guys) and the grass was quite long. The seeds were 2-3' high and my little 18hp tractor would grumble a bit through some of the thick stuff.

I reckon I can do a little over 1 acre per hour in those conditions.

I hope this helps.

Looks like my reckoning is pretty right as per those tables.

Cheers /forums/images/graemlins/grin.gif

 

[JohnMiller3]

Re: acres per hour w/ 48\" rotary cutter

Mowing with 5' cutter...
Mowing Estimates for 1 Hour w/ 100% efficiency
Acres Completed in (1hr@5mph) 3.030

Width of mower (ft) 5 @ 100% Efficiency 85%
Gears MPH Acres Done
Gear L-1 1.86 1.127 0.958
Gear L-2 2.67 1.618 1.375
Gear L-3 3.77 2.285 1.942
Gear L-4 5.28 3.200 2.720
~~~~~~~~~~~~ from Miller's equation... /forums/images/graemlins/wink.gif

Depending on how smooth and wide open the terrain is, I normally cut ~~ 5 mph...

 

[JohnMiller3]

Re: acres per hour w/ 48\" rotary cutter

This is for 48" cutter:
Mowing Estimates for 1 Hour w/ 100% efficiency
Acres Completed in (1hr@5mph) 2.424

Width of mower (ft) 4 @ 100% Efficiency 85%
Gears MPH Acres Done
Gear L-1 1.86 0.902 0.767
Gear L-2 2.67 1.295 1.100
Gear L-3 3.77 1.828 1.554
Gear L-4 5.28 2.560 2.176

 

[Bird]

Re: acres per hour w/ 48\" rotary cutter

100% efficiency sounds great, but I don't know anyone who can get all the way there. /forums/images/graemlins/laugh.gif

My own experience with a 4' rotary cutter and a B7100, going very slowly along the perimeter fences, backing into one odd shaped corner without room to turn around, backing around and under 9 trees in the pasture, not running as fast as I otherwise would have because of the rough ride, etc., I averaged about about .75 acres per hour.

Then with the 5' rotary cutter and a B2710, I averaged about 1.2 to 1.5 acres per hour, partly due to the wider cutter, partly due to the smoother ride, and partly due to the fact that I'd just decided to drive faster. Now if you don't have trees, don't try to get too close to fences, have smooth ground, no tank (pond) dams, no ravines, don't use too much overlap, then I suppose those charts are pretty good. /forums/images/graemlins/wink.gif

 

[herbenus]

Re: acres per hour w/ 48\" rotary cutter

I think if you gave us the size of the farm then there might be recommendations on mower size for you. I'm not sure how long it takes me to mow but I'm guessing the .75 to 1 acre an hour is close with my 48" shredder. I have 6-1/2 acres but don't mow within 30 feet of fence and use riding mower around house. I have lots (LOTS) of trees. I can tell you that I've concluded 48" is too small. It works. I can do the place in 1 day, but when it's 110 degrees out (starting in May around here) I stretch it to two days. I'm planning on a 5 foot RMM this year which I expect will help tremendously.

I don't push the speed too much since I did that once and hit a stump going around a corner. Rear wheel well off ground... After cleaning out my shorts I think I was down in lowest gear for a while.

Just my two cents worth.

 

[hazmat]

Re: acres per hour w/ 48\" rotary cutter

<font color="blue"> I think if you gave us the size of the farm then there might be recommendations on mower size for you. </font>

Well, with my 18.5HP tractor I don't think I'd want to go any bigger than the 48" cutter. I have a 5' Mid Mount Finish mower now. while I haven't run out of power yet, I also haven't let the grass grow more than a couple inches before mowing it (the 1/3 rule). Since this property will be 2 hours from me, I only expect to be cutting a few times per year. Thus a bigger cutter would require a bigger tractor.

Thanks to everybody for sharing their experiences (and formulas). /forums/images/graemlins/grin.gif If they buy a place with 30+ acres of fields, I guess I'll have to convince pops that he needs a bigger tractor. I'll just have to sneak up there before he does to cut the fields /forums/images/graemlins/cool.gif. More seat time for me (insert Tim Allen grunts here)

 

[herbenus]

Re: acres per hour w/ 48\" rotary cutter

And of course my experience down here in Texas will be different than up there. Here grass starts growing in March and requires cutting every 2 weeks in the fields during middle summer and every week up by house. I suspect the frequency is less up there and the season shorter.