6m 750a changing offset

[Feldspar]

Are you sure the fix got it 100% right ? Would only have to be a couple degrees out to cause the very issue you are describing

Would it make it crab in a variable way though?

No, I am not 100% sure that it is right. I'm not sure, for example, whether there was a slight misalignment on the frame that wasn't picked up.

 

[Feldspar]

Well if @Timbo1080 checks his drill and it's all straight, then that makes it less likely it's a geometry. Does make you wonder though, if they can get the wheels that far out, whether there are other geometry issues. Still not sure that would explain why it's wandering.

 

[Clive]

Would it make it crab in a variable way though?

No, I am not 100% sure that it is right. I'm not sure, for example, whether there was a slight misalignment on the frame that wasn't picked up.

Do you know anyone local into motorsport who could lend you a few lasers ? Sound to me like first thing you shod be doing is making sure it’s all 100% square and pulling straight and central on a flat concerete service

If you can’t borrow lasers you can set up a string box (old fashioned motorsport way but equally accurate) and take measurements

 

[Feldspar]

Do you know anyone local into motorsport who could lend you a few lasers ? Sound to me like first thing you shod be doing is making sure it’s all 100% square and pulling straight and central on a flat concerete service

If you can’t borrow lasers you can set up a string box (old fashioned motorsport way but equally accurate) and take measurements

We've got lasers for doing building work. Would they work?

Same question again though, would slightly off geometry explain this wandering offset?

 

[Robt]

Yes!

 

[Feldspar]

Yes!

To which question?

 

[Robt]

If the machine isn’t square it won’t pull square, the more soil drag the worse or better the problem. Hold a spade at an angle and pull it behind you, do the same and put pressure on it....... differing soil types will pull the machine differently

 

[Feldspar]

If the machine isn’t square it won’t pull square, the more soil drag the worse or better the problem. Hold a spade at an angle and pull it behind you, do the same and put pressure on it.......

Good point. Now I'm getting nervous that the thing still isn't square and it's out of warranty.

 

[Tractor Boy]

Good point. Now I'm getting nervous that the thing still isn't square and it's out of warranty.

I would suggest that that isn’t a warranty issue. If it’s still not been aligned correctly they should do it at their expense. It’s not as if you bent it is it. I’m going to check my 4m tomorrow and make sure that’s aligned as it’s a similar age to yours.

 

[Feldspar]

I would suggest that that isn’t a warranty issue. If it’s still not been aligned correctly they should do it at their expense. It’s not as if you bent it is it. I’m going to check my 4m tomorrow and make sure that’s aligned as it’s a similar age to yours.

Let me know what you find.

 

[Timbo1080]

Me too to everything above!! Will report back.....Would seem odd that I had the opposite issue wrt shallow drilling and deep drilling though - If the wheels were misaligned, then I would expect that:

Deep drilling (beans etc), there would be less mass on the wheels, and therefore less error, and

Shallow drilling (OSR or on cultivated ground etc), there would be a greater mass on the wheels and therefore a greater error.....

...as you are describing.

I am seeing the opposite.......!

From that I would hazard a guess that our Drawbar is bent (or some part of the chassis-I can’t quite think clearly on this right now!), whereas your wheels/axles are still misaligned......

 

[Farmer Roy]

err, please bear with me as Im unfamiliar with these 750a machines, although I do have a lot of experience with that style of single disc planter row unit

are all the single disc units on each row facing the same direction ? ie - is the front row all "left hand" units & the rear row all "right hand" units, or is each row balanced out with an equal number of left & right ?

if the offset is inconsistent ( left / right / hard ground / soft ground / hill / flat etc ) is it because of the side draught of the units varying in different conditions ie all the front units are left hand, hit harder soil & push whole machne to the right ? Then softer soil & machine runs "straight" again ? Or uneven ground, more pressure on front or rear rows, causing side draught ?

or am I just barking up the wrong tree?

any planter Ive ever made up out of these style of single disc units Ive always had equal number left & right on each bar to balance out the side draught

 

[Timbo1080]

@Farmer Roy Yes, equal lefts and rights for front and rear.

I’m struggling to find a reasonable and sufficiently accurate way of measuring the geometry, without seconding the local tyre fitting company with their wheel alignment lasers....

@Feldspar @Tractor Boy how are you doing this, and where are you looking to take the dimensions?! Everything looks out of kilter to me now, but that’s almost certainly just my eyes.....

 

[principal skinner]

If that was my drill I wouldn’t have accepted a bodge/repair on it. It would have been sent straight back to where it came from.

 

[Feldspar]

If that was my drill I wouldn’t have accepted a bodge/repair on it. It would have been sent straight back to where it came from.

They had a professional coded welder in to do it. Couldn't bodge it because if something came off whilst on the road, they'd be in trouble. As with all these things (I have the most experience with combines), most of the contracts you sign are not very favourable to the farmer.

 

[principal skinner]

Just because a coded welder done the job doesn’t mean it’s welded square!

Is it on finance? Get the finance company involved if it isn’t all true and square, not fit for purpose surely?

 

[Feldspar]

Just because a coded welder done the job doesn’t mean it’s welded square!

Is it on finance? Get the finance company involved if it isn’t all true and square, not fit for purpose surely?

I haven't checked whether it is square or not yet.

 

[Clive]

We've got lasers for doing building work. Would they work?

Same question again though, would slightly off geometry explain this wandering offset?

not sure how to do it with building kit - you could probably bodge something up with that and a few mirrors etc but by the time yo have done that the good old string box method would be as quick (and is accurate) - just google how to set up race car geometry with string or similar as I expect there are guides online

 

[Clive]

We've got lasers for doing building work. Would they work?

Same question again though, would slightly off geometry explain this wandering offset?

without doubt if its not square then no matter what you do with GPS etc it will never be right

 

[Simon Chiles]

without doubt if its not square then no matter what you do with GPS etc it will never be right

Exactly.