Ground speed as a function of gear number and engine speed-M4500

[JerryMT]

We have a 2wd M4500 that I use to spray with. I'm trying to keep my ground speed at 4mph to spray 10 g/ac. I have a wonderful chart on my tractor fender and also one in the operators manual that lists ground speed as a function of gear number. Unfortunately, they do not give the engine rpm that for which those speeds are based on!

I know how to determine the ground speed the hard way but I don't want to run a test program in each gear to determine the drive ratio and then calculate the speed.

Does anyone know what engine speed go with the speed charts for the M4500? I'm trying to spray this afternoon so any help would be appreciated.
Thanks in advance.

 

[North Idaho Wolfman]

We have a 2wd M4500 that I use to spray with. I'm trying to keep my ground speed at 4mph to spray 10 g/ac. I have a wonderful chart on my tractor fender and also one in the operators manual that lists ground speed as a function of gear number. Unfortunately, they do not give the engine rpm that for which those speeds are based on!

I know how to determine the ground speed the hard way but I don't want to run a test program in each gear to determine the drive ratio and then calculate the speed.

Does anyone know what engine speed go with the speed charts for the M4500? I'm trying to spray this afternoon so any help would be appreciated.
Thanks in advance.

Most likely the speed was calculated at PTO RPM speed.

If you have a smart phone it can tell you MPH too.

 

[nickelplated5s]

Anything with GPS in it. Most of them will allow you to run the perimeter and give you the acreage.

 

[JerryMT]

I contacted the local dealer 's service manager and he agrees with NIWM. He says it is at 540 pto speed which in the case of the M4500 is 2193 rpm.

 

[boz1989]

Does the chart specify the tire being used? Or is it approximate. If you want 4mph, I would check it against something else.

Sent from my LGMP260 using Tapatalk

 

[Kubota Newbie]

Yes the chart (in my OM anyway) does spec tire size, which for the M4500 is 14.9-28. I've got M5500 rubber on my M4500 (16.9-28) which is slightly taller as well so I run a tad faster than the chart, but not really by much.

You should really calibrate your sprayer by catching the nozzle output over a measured and timed course. Ohio State has a good calibration fact sheet that guides you through the process https://ohioline.osu.edu/factsheet/fabe-520 . Basically you measure off a course that represents 1/128th of an acre based on your nozzle spacing and then collect the output from a nozzle. the fluid ozs. collected = gallons/acre. The beauty of this method is that you simply time the course in the gear and at the throttle setting you want to use to spray with and then you don't have to worry about exact ground speed. Been doing it this way for 35 years, simple!
You should also technically check all of your nozzle outputs to make sure they are in an acceptable range (I think 10 %, but not sure off the top of my head).

 

[JerryMT]

Does the chart specify the tire being used? Or is it approximate. If you want 4mph, I would check it against something else.

Sent from my LGMP260 using Tapatalk

Yes, the stdard for the M4500 rears is 14.9 x 28 and that's what specified for the speed numbers in the OM table.

 

[JerryMT]

Yes the chart (in my OM anyway) does spec tire size, which for the M4500 is 14.9-28. I've got M5500 rubber on my M4500 (16.9-28) which is slightly taller as well so I run a tad faster than the chart, but not really by much.

You should really calibrate your sprayer by catching the nozzle output over a measured and timed course. Ohio State has a good calibration fact sheet that guides you through the process https://ohioline.osu.edu/factsheet/fabe-520 . Basically you measure off a course that represents 1/128th of an acre based on your nozzle spacing and then collect the output from a nozzle. the fluid ozs. collected = gallons/acre. The beauty of this method is that you simply time the course in the gear and at the throttle setting you want to use to spray with and then you don't have to worry about exact ground speed. Been doing it this way for 35 years, simple!
You should also technically check all of your nozzle outputs to make sure they are in an acceptable range (I think 10 %, but not sure off the top of my head).

I did a weigh calibration on my sprayer before I put it into service 12 tears ago so I know the flow from the boom. I just needed to get the speed correct and knowing the engine rpm that goes with the speed table I can scale the ground speed as a function of engine rpm.

 

[Kubota Newbie]

So..... I don't know what material you're spraying but.... Nozzles wear out, some of them really fast, which significantly changes the rate/acre. You should calibrate annually (maybe more if you farm a lot). The nozzle should be replaced if the output is more than 10% over the catalog specification for a given pressure. You of course can adjust output with pressure, but if it is worn that much the pattern and resultant coverage probably sucks too. Some of the rates for material these days are really low. I calibrate even my lawn sprayer every year. I'm using product that goes on in ounces/acre (post emerge materials for crabgrass for example) and an over application of one of the products I use would turn the whole yard white for the rest of the summer. Not cool.
To go one step further... some of the Dicamba premixes for GMO crops now specify exactly what nozzles can and cant be used and the pressure operating range and boom height as well.

 

[Bulldog777]

If you have a smart phone you can download a speedometer app. I downloaded one to check the speed on my tractor.

Sent from my SM-G955U using Tapatalk

 

[JerryMT]

So..... I don't know what material you're spraying but.... Nozzles wear out, some of them really fast, which significantly changes the rate/acre. You should calibrate annually (maybe more if you farm a lot). The nozzle should be replaced if the output is more than 10% over the catalog specification for a given pressure. You of course can adjust output with pressure, but if it is worn that much the pattern and resultant coverage probably sucks too. Some of the rates for material these days are really low. I calibrate even my lawn sprayer every year. I'm using product that goes on in ounces/acre (post emerge materials for crabgrass for example) and an over application of one of the products I use would turn the whole yard white for the rest of the summer. Not cool.
To go one step further... some of the Dicamba premixes for GMO crops now specify exactly what nozzles can and cant be used and the pressure operating range and boom height as well.

You're right. I need to check the calibration for the TeeJet nozzles but my immediate problem is getting the speed set correctly and for that I need the engine rpm which was used to derive the chart. Thanks for the reminder.