The Combine Forum banner

1 - 20 of 25 Posts

·
Registered
Joined
·
939 Posts
Discussion Starter #1
When calibrating my air cart, 2280 tow between mechanical drive, the displayed rate is never correct. Always shows lower than whats being applied. Hectares are correct, ground speed correct, machine width correct, sprocket teeth numbers are correct, sample weighed with a digital scale.

Cailbration proceedure...
Drive around so product settles
Set slides at 35
Prime meters
Go to cal in display
Set desired rate
Zero meter cal #
Turn on tanks
Push go
Crank meter
Weigh products
Enter product mass
Set slides accordingly
Go to field
Start seeding and see rate is 15ish kg/ha low
Keep seeding and see tank seems to be emptying quicker than i think. Say f it its gotta be close and empty tank only to see its over aplying.


Any suggestions as to why that would be. Its getting old setting rates based off acres per fill.
 

·
Registered
Joined
·
939 Posts
Discussion Starter #3 (Edited)
Why not run the weights after you adjust the slides?

If it’s consistent you might just have to run a correction factor.
I guess i can try count how many cranks per hectare while the carts seeding and then calculate based off that.

Its supposed to be that you do the meter calibration, set the slide and go to the field and set your rate off what the display is showing
 

·
Registered
Joined
·
481 Posts
Did you account for the wight of the bag. Or that dose not matter for your cal? And do you know for sure you have the bushels in the tank by wight. We wight the product that go’s in the tank to Make sheer it’s metering right. We found you will always have less in the tank versus it will hold.
 

·
Registered
Joined
·
5,412 Posts
Since it is consistently applying heavy based on a small sample you could try this. Suppose it applies 9% too heavy as a rule, when you weigh your calibration sample, just multiply that sample weight by 109%, or 1.09. As an example 30 Lbs of sample would be considered as 32.7 Lbs when selecting your sprockets or entering it into your computer on many machines.

This will make the meter setting 9% slower. Many early air seeder designs have an engineered flaw in the calculation mathematics because they never ever wanted anyone to have to sow a small field twice because of an excessively light seed application, particularly on small seed rollers.
 

·
Registered
Joined
·
939 Posts
Discussion Starter #7
Did you account for the wight of the bag. Or that dose not matter for your cal? And do you know for sure you have the bushels in the tank by wight. We wight the product that go’s in the tank to Make sheer it’s metering right. We found you will always have less in the tank versus it will hold.
Have you got the right sprocket combination for your drill width on your cart?
Yes bag weight is accounted for. No i dont weigh into the cart so i dont know exactly whats going in. According to the book the sprocket combination is correct... acres and speed are correct.
 

·
Registered
Joined
·
939 Posts
Discussion Starter #8
Since it is consistently applying heavy based on a small sample you could try this. Suppose it applies 9% too heavy as a rule, when you weigh your calibration sample, just multiply that sample weight by 109%, or 1.09. As an example 30 Lbs of sample would be considered as 32.7 Lbs when selecting your sprockets or entering it into your computer on many machines.

This will make the meter setting 9% slower. Many early air seeder designs have an engineered flaw in the calculation mathematics because they never ever wanted anyone to have to sow a small field twice because of an excessively light seed application, particularly on small seed rollers.
But i wont know how much its off till i run out of seed and i would have to not change the rate till that happens to know what % its off. Im loading seed straight out of the bin so not real easy to weigh it. its a 2009 cart so would that be considered early design? I would like to figure out whats wrong and correct it not just work around it.
 

·
Registered
Joined
·
2,736 Posts
Have you seeded 10-15 acres then re-calibrated?

For us it doesn’t seem to matter how you fill the meter it isn’t the same as seeding for a bit. Calibration is always off a bit and after redoing a known weighed amount works out real close.

If you don’t know how much you have in the tank it’s impossible to know if your applying the correct amount.
 

·
Registered
Joined
·
5,412 Posts
2280 tow between mechanical drive, the displayed rate is never correct. Always shows lower than whats being applied.

I believe your sentence above tells you generally what to expect before you run out of seed.

I don’t think that you can achieve high accuracy on seeding rates on high acreage with only the results in a collected sample. I have always used real world calculations and adjusted the cal factor on variable rate air carts, which would be increasing the cal factor by 1% will make the meter turn 1 % slower and cause a 1% lower seed rate.

On a sprocket driven cart you may not have a cal factor shown in the process, it would be easier to simply adjust the scaled weight of the sample. Running sample calibrations over and over again is like dealing a new round of cards leaving you with no simple to define start point.
.
 

·
Registered
Joined
·
939 Posts
Discussion Starter #14
So resolved i think... last night after posting and reading joesixpacks reply i counted how many crank revolutions to make .1 hectare. This morning i cranked it out and weighed product times 10 to get rate per acre. Then did a meter cal. Turns out that when the computer calculated the meter cal # it was incorrect. If i calculate the meter cal # based of the targets and product mass and enter it into the display the rate on the display is within a couple kg/ha of what i measured.
 

Attachments

·
Registered
Joined
·
939 Posts
Discussion Starter #15 (Edited)
So the issue isnt resolved... moved onto canola and things worked out pretty close. Now doing soybeans and not good again. Filled cart and calibrated etc should be good. Went to field did a few rounds looked heavy so got out and checked calibration. Cranked out 1/10th hectare and weighed and got 7.8 kgs, should be 8.7 kept seeding and its working out to about 94kgs/ha. So im looking for ideas as to why when turned by hand i get a low reading and when actually seeding i get a different higher rate??? Its a precision air 2280 cart caseih which is same as flexicoil im told.
 

·
Registered
Joined
·
787 Posts
So the issue isnt resolved... moved onto canola and things worked out pretty close. Now doing soybeans and not good again. Filled cart and calibrated etc should be good. Went to field did a few rounds looked heavy so got out and checked calibration. Cranked out 1/10th hectare and weighed and got 7.8 kgs, should be 8.7 kept seeding and its working out to about 94kgs/ha. So im looking for ideas as to why when turned by hand i get a low reading and when actually seeding i get a different higher rate??? Its a precision air 2280 cart caseih which is same as flexicoil im told.

We have always found that doing a stationary crank and weigh only gives a general idea of the rate. Go seeding and calculate area seeded by weight used and it usually comes out up to 10% higher or lower.
 

·
Registered
Joined
·
939 Posts
Discussion Starter #17
We have always found that doing a stationary crank and weigh only gives a general idea of the rate. Go seeding and calculate area seeded by weight used and it usually comes out up to 10% higher or lower.
So what do you do? Is calibrating while driving around more accurate?
 

·
Registered
Joined
·
4,068 Posts
We measure out a 200 foot run and calibrate it that way. Seems to be pretty much bang on unless the product being put down changes a bit from load to load.
 

·
Registered
Joined
·
1,070 Posts
Can't understand as we have had two flexicoil seeders ( first was a full mechanical drive) and now a 5000 with a 2320 tank and the metering was always bang on from setting the meters . Only problem we had with the mechanical one was the one way sprags had gotten loose and product delivery at canola rates was sporadic . Don't you have to crank the handle a certain number of times to get a tenth of an acre to calibrate the rollers ? I remember that on the geardrive cart that there was some discrepancy with the sprockets due to the cultivator size that we had to take into account . I think we had to first figure out how far we had to drive to get a tenth of an acre then count the turns and use that to calibrate the rollers and then we had to adjust the acre / speed calibration to get that right .
 
1 - 20 of 25 Posts
Top