My 2020 has 16.9-30 tires on the rear. According to the tach, at 1500rpm the 'speedometer' indicates a bit more than 3 mph in 5th gear. Now I can walk 4 mph. And in 5th gear while mowing with the NH451 mower, the tractor is running along at what I would consider a good jog, certainly more than 4mph. Is there any way to determine how fast I'm actually moving other than timing it on a measured course, which may be the easiest way, considering.
2020 ground speed
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deserteagle71
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Do you have any kind of GPS unit? Or a smart phone, which usually has GPS circuitry inside?
deserteagle71
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Here is the relevant portion of the owner's manual for my 2020...but the tire size is not what you have.
beenthere
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Yup.. Tape measure and stop watch would be quite accurate.
Pacing and second hand would be close enough too.
I've got that chart in my 2020 book too, but it doesn't tell me anything. Strange thing is looking at my tach/speedo the one on the tractor, which is a replacement, says almost 7mph in 5th gear at 1500 rpm. 6th gear is 10+mph on the speedo. I was looking at tach/speedos on line so who knows what they are, as well as the one I've got.
What I just did was measure out .5 miles with the P/U. Drove the tractor over the same .5 mile in 5th gear. Takes 8 min 44 sec on the stop watch. Then drove back in 6th gear. Takes 5 min 58 sec. Now I'm trying to wrack my brain to figure out how to convert min/half mile into mph. I used to be good at math, but I've lost my mojo with the age.
I did figure if I'm moving 3mph and cutting 7' at a whack and it takes me 3 hours that's 7x3x5280 sq feet, divide that by 43500 or so and I get 2.5 acres mowed in 3 hours. I know the field is larger than that. It's about 8-10 acres. So 7mph may be about right for 5th gear because that is what I was using.
But if someone can steer me from 'min/half mile' into m/h that would be great.
What I just did was measure out .5 miles with the P/U. Drove the tractor over the same .5 mile in 5th gear. Takes 8 min 44 sec on the stop watch. Then drove back in 6th gear. Takes 5 min 58 sec. Now I'm trying to wrack my brain to figure out how to convert min/half mile into mph. I used to be good at math, but I've lost my mojo with the age.
I did figure if I'm moving 3mph and cutting 7' at a whack and it takes me 3 hours that's 7x3x5280 sq feet, divide that by 43500 or so and I get 2.5 acres mowed in 3 hours. I know the field is larger than that. It's about 8-10 acres. So 7mph may be about right for 5th gear because that is what I was using.
But if someone can steer me from 'min/half mile' into m/h that would be great.
Diggin It
Super Star Member
I used to check my car speedometers using freeway mile markers at 60MPH. If I made 10 miles in 10 minutes, I figured it was pretty accurate. I don't think you can do that with a 2020 though.
I just found the converter on line. Convert minutes per mile to miles per hour - speed converter
According to that my 8:44 min or 17:28 min/mile or 17.47 min in decimal is about 3.4mph. I just don't believe it somehow. The acreage doesn't add up with the mowing time unless I've made an error in that math.
Actually 3.4mph is what I had finally calculated, I just didn't believe it. Shoot I can walk 4mph easy and the tractor looks faster than that unless it's deceptive because I'm on this machine.
According to that my 8:44 min or 17:28 min/mile or 17.47 min in decimal is about 3.4mph. I just don't believe it somehow. The acreage doesn't add up with the mowing time unless I've made an error in that math.
Actually 3.4mph is what I had finally calculated, I just didn't believe it. Shoot I can walk 4mph easy and the tractor looks faster than that unless it's deceptive because I'm on this machine.
beenthere
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calculated 0.5 mile in 8 min 44 sec is 3.44 mph, so your table is pretty close.
You moved 0.5 mile in 8.73 minutes or 0.1455 hours.
Divide 0.5 by 0.1455 and you get 3.436 mph
You moved 0.5 mile in 8.73 minutes or 0.1455 hours.
Divide 0.5 by 0.1455 and you get 3.436 mph
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So what is the acreage cut calculation if I mow 3.4mph for 3 hours and cut 7' at a pass. I calculate 2.4 acres?
The NH451 mower instructions say it can move at 8mph. But there's no way I can move that fast on my hills and ground. I'm lucky to be in 5th gear. It's much more comfortable in 4th gear but in my South field I can get into 5th. North field is so hilly and so many trees and obstructions 4th gear is about all I can accommodate.
The NH451 mower instructions say it can move at 8mph. But there's no way I can move that fast on my hills and ground. I'm lucky to be in 5th gear. It's much more comfortable in 4th gear but in my South field I can get into 5th. North field is so hilly and so many trees and obstructions 4th gear is about all I can accommodate.
Zebrafive
Super Member
I get 8.65 acres
beenthere
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Agree, 8.65 acres if there is zero overlap and maintain constant 3.4 mph.
Calculate 3.4 mph x 3hrs = 10.2 miles traveled
10.2 miles x 5280 ft/mile = 53,856 ft traveled
53,856 ft x 7' cutting width = 376,992 sqft mowed
376,992 sqft divide by 43,560 = 8.65 acres mowed
Calculate 3.4 mph x 3hrs = 10.2 miles traveled
10.2 miles x 5280 ft/mile = 53,856 ft traveled
53,856 ft x 7' cutting width = 376,992 sqft mowed
376,992 sqft divide by 43,560 = 8.65 acres mowed
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Tx Jim
New Member
My rule of thumb acre calculator I was taught many yrs ago shows 7.14 acres. 3.4 mph X 7' cut= 23.8 ÷ 10=2.38 acres cut per hr X 3hrs = 7.14 acres mowed. I agree cell phone should have a MPH calculator.
Got it. In my calculations, I forgot to multiply the 3.4mph by the hours. That makes sense now. I can believe that filed is about 9 acres. So the 3.4mph must be correct. I was moving along pretty consistently with few bogs and few time consuming turns.
I never have been able to master those right angle turns and not leave a pile there or an uncut piece. If necessary, I'll stop, back up and start again.
Thanks guys.
I never have been able to master those right angle turns and not leave a pile there or an uncut piece. If necessary, I'll stop, back up and start again.
Thanks guys.
Tx Jim
New Member
DogT
You can measure the acres in this field from above. The website I utilize is ACME Planimeter
You can measure the acres in this field from above. The website I utilize is ACME Planimeter
Thanks Jim, according to that ACME map, the field is 4.6 acres. I also found that my county has a gis map with a similar thing where I can draw a perimiter and it calculates the area. It agrees with 4.6 acres. I guess I'm not mowing as much as I think.
topgun05
New member
calculate your minutes and seconds into total seconds. divide that number into 1800. [since using a half mile not full mile (3600)]
your 6th gear = 358 seconds 1800 / 358 = 5.02mph
prefer using an app for smartphone, and for accuracy sake don't like using the truck to guess a half mile.
could Google distance in feet for some "country" miles locally
your 6th gear = 358 seconds 1800 / 358 = 5.02mph
prefer using an app for smartphone, and for accuracy sake don't like using the truck to guess a half mile.
could Google distance in feet for some "country" miles locally
LD1
Epic Contributor
Google Earth also has a tool to measure acreage as well as findlotsize.com.
The general rule is mph x cut width divided by 10. Figures about 80% efficiency.
No one ever nows at 100% efficient.
If you average 6" overlap, and only cutting 6.5' per pass, that alone knocks 7% off. Then you have turns or the last pass that may only be a foot wide. The formula above takes all that into account.
If your field is 800' long, it takes 160 seconds at 3.4 mph to make the trip. If it takes you 10 seconds to turn around...you loose another 6% efficiency. So now you are getting ever closer to 80% and the formula I listed.
Just what are you trying to figure? How big exactly is the field according to county GIS, or Google, etc? And how long does it actually take you to cut it
The general rule is mph x cut width divided by 10. Figures about 80% efficiency.
No one ever nows at 100% efficient.
If you average 6" overlap, and only cutting 6.5' per pass, that alone knocks 7% off. Then you have turns or the last pass that may only be a foot wide. The formula above takes all that into account.
If your field is 800' long, it takes 160 seconds at 3.4 mph to make the trip. If it takes you 10 seconds to turn around...you loose another 6% efficiency. So now you are getting ever closer to 80% and the formula I listed.
Just what are you trying to figure? How big exactly is the field according to county GIS, or Google, etc? And how long does it actually take you to cut it
