How to make 6m 750a pull straight?

[Big-Al]

I run mine at 5.98 on the rtk box it does leave a slight gap (only slight but feel not running on tracks now the wheeled tractor moves a lot on rtk even) and is a pig to get it central and running straight i have no link arms but wedge blocks that need to be tight no sway at all, it is embarrassing drilling someone else's and they are on 24 m rtk and you have to drill at 23.92m, i can see no reason why they cant tighten up the drill to run a true 6m by putting an extra coulter in or space to suit its not rocket science, i also have the new tab tubes, told i was testing for jd but seems everyone is getting them to test, i not moaning ( much) as i don't think there is a better machine to put a seed in the ground precisely where it should be, in all conditions as the 750a. as my spring barley is coming up fantastically again also running mine at 11.5kph think it is better than 13kph i ran at last year.

Regards

 

[Tractor Boy]

Ours pulls off to the left (as you look at the drill from behind) rather than the right. Odd.

It might be 4cm offset left actually.

 

[Breakthru]

Having got it wrong last autumn quite a bit despite fiddling around, we have now worked out that we need to put a 8-9cm offset in to make our 750a bouts match up. Ideally I'd like not to have to do this. Have checked tyre pressures, link arms, but that hasn't solved the problem.

Any ideas of how to make the drill pull in line with the tractor?

As in another string if you have a separate aerial put it on the front centre of the drill, that way it doesn't matter where the tractor is especially on sidlings.

 

[Fuzzy]

Having got it wrong last autumn quite a bit despite fiddling around, we have now worked out that we need to put a 8-9cm offset in to make our 750a bouts match up. Ideally I'd like not to have to do this. Have checked tyre pressures, link arms, but that hasn't solved the problem.

Any ideas of how to make the drill pull in line with the tractor?

Is the drawbar actually in the centre of the drill ? Maybe you could measure it to check ?

 

[Feldspar]

Is the drawbar actually in the centre of the drill ? Maybe you could measure it to check ?

Yes, I think we need to do some more measuring to check the basics.

 

[Feldspar]

As in another string if you have a separate aerial put it on the front centre of the drill, that way it doesn't matter where the tractor is especially on sidlings.

Main problem is the extra cost of the GPS, especially as it would need to be RTK accuracy.

 

[Feldspar]

I run mine at 5.98 on the rtk box it does leave a slight gap (only slight but feel not running on tracks now the wheeled tractor moves a lot on rtk even) and is a pig to get it central and running straight i have no link arms but wedge blocks that need to be tight no sway at all, it is embarrassing drilling someone else's and they are on 24 m rtk and you have to drill at 23.92m, i can see no reason why they cant tighten up the drill to run a true 6m by putting an extra coulter in or space to suit its not rocket science, i also have the new tab tubes, told i was testing for jd but seems everyone is getting them to test, i not moaning ( much) as i don't think there is a better machine to put a seed in the ground precisely where it should be, in all conditions as the 750a. as my spring barley is coming up fantastically again also running mine at 11.5kph think it is better than 13kph i ran at last year.

Regards

I wondered whether there is space to nudge the coulters on the edge of the drill out a bit? Haven't checked. Stupid design not to have it at a true 6m.

I think one of the designers from the factory is meant to be at our local dealer this week. There was some talk of them coming to see us to have a general chat. Having heard any more about that though.

 

[Simon Chiles]

Yes, I think we need to do some more measuring to check the basics.

I'd start by checking if the receiver is actually in the centre of the tractor, after all it only needs to be 20mm out to give you a 4cm discrepancy in tracking. I'd also check the check chains to ensure they are central and the spacers you might have on the lower link pins. I got my son ( he used to be a precision engineer making aircraft components to fractions of a mm ) to machine my spacers.

 

[Simon Chiles]

Main problem is the extra cost of the GPS, especially as it would need to be RTK accuracy.

Mine still tracks ok sideways across banks that have a hillsider combine reach it's chassis limit. If the drill runs downhill of the tractor one way it does the same amount when you go back the opposite way.

 

[Big-Al]

I wondered whether there is space to nudge the coulters on the edge of the drill out a bit? Haven't checked. Stupid design not to have it at a true 6m.

I think one of the designers from the factory is meant to be at our local dealer this week. There was some talk of them coming to see us to have a general chat. Having heard any more about that though.

I would rather have a 6.05 m dill than a 5.98m, think my drill slightly to right as i have the wedge on the right in further to get it to nearly match maybe the 2016 build drills, as i had the right wing which was lower than the left (looking from the back) had to shorten the depth bar to adjust the sag from new.

Regards

 

[cows sh#t me to tears]

Not sure how expensive this is or what is involved ....but an option none the less.

 

[yellow belly]

if the front row of coulters is slightly deeper than the back it will pull slightly off centre a small difference in depth is all that is needed
the other possibility is that the drawbar is not perfectly at 90 degrees to the frame either manufacturing tolerance or one side has been pulled up against something solid and a small imperceptible bend in the frame drawbar

when we used markers we would adjust the marker on each side to get an even match
with a well set up gps the offset needs to be consistent

any drill form outside coulter to outside coulter is total width less one coulter gap wide
I prefer a drill to be slightly over wide so misses are not noticed alternatively as seems above most farmers drill a narrower width than the accrual width

 

[Breakthru]

if the front row of coulters is slightly deeper than the back it will pull slightly off centre a small difference in depth is all that is needed
the other possibility is that the drawbar is not perfectly at 90 degrees to the frame either manufacturing tolerance or one side has been pulled up against something solid and a small imperceptible bend in the frame drawbar

when we used markers we would adjust the marker on each side to get an even match
with a well set up gps the offset needs to be consistent

any drill form outside coulter to outside coulter is total width less one coulter gap wide
I prefer a drill to be slightly over wide so misses are not noticed alternatively as seems above most farmers drill a narrower width than the accrual width

Our local engineer (now deceased) used to set up tow bars slightly off centre so that they would pull straight. With caravans and stock trailers it stopped them wandering.

 

[marco]

any chance the drill isnt running level in work?

 

[H.Jackson]

Confession time transfering the GPS bracket to latest hire tractor and found receiver to be 18mm off centre. Have removed off set and drilled some covers will check under lap.when passing

 

[Clive]

You can't expect to buy a 6m. Drill from the USA can you, they work in feet and inches? I bet your drills are actually more like 19 feet wide which is about 6" less than 6m. QED?

its a european built drill - don't think the 750a is even available in the USA ?

 

[Clive]

Didn't know that, but I bet it's based on feet and inches in the first place. Of course I may be wrong.
Just seems funny that it doesn't appear to be as wide as advertised. Wouldn't be the first machine to not be quite as wide as advertised.
We used to have a Sulky "4 metre" seed drill which was about 3m 90cm really. Using tramlines on the drill meant you never had missed bits with the sprayer.

They are built in the Kverneland factory I believe