Question about steering wheel control

Hi there. I’m a fellow farmer from Romania, turned recently into farming after 10 years of software engineering. Running a 6210R here at farm. As I’m looking into autosteering, I have identified the two trouble points for which I’m trying to find a solution. First would be the wheel angle sensor for which I suppose at the end I will retrofit the John Deere’s one since it already has the foreseen position on the wheel mechanism and for which I have the manual. The second point is of course the steering wheel control. I cannot seem to find anywhere here on forum a procedure or tutorial for building the mechanism. Moreover, I see on YouTube various setups like the following one: AgOpenGPS V4 : premier tour de Volant , first trial steering wheel #Shorts - YouTube which seem to include some nicely 3D printed components. Could you kindly guide me where I could get - it they exist - the STL files for such pieces or at least a link some sort of description for a mechanism to connect the motor to the steering wheel? Thank you.

Hello, i can make you a 3d model for printing vor CNC machining but i need the measurements of the wheel and the console wäre the stearing wheel is mounted

I wan

1 Like

this is mix of 3d parts and steel parts it is related of you motor drive line …

project is not finished yet but initial topic for idea …

when you disassemble the steering wheel and initial cover:
you see this

disassemble the two screw and cut the plastic ( thanks JD designer!)
DSC_0628o (2)

fix bracket with original screw
DSC_0628o (3)
reclosed the cover and refix the sterring wheel and result for fixed bracket

DSC_0628o (5)

assembled steering parts with M5 bolt

DSC_0628o (6)

to git this result DSC_0628o (7)

next will be motor bracket when i more confident of my design

if you want full plastic that i check before


Thank you for your reply both AndreasTT and bricbric. bricbric, your setup looks very nice, about the full plastic model from cerea forum, do you confirm it is working? It’s not as nice and reliable as your design but I have access to a 3D printer, I do not have access to CNC for metal parts.
Maybe you will consider selling a full kit when you will make also the motor bracket. I will be interested in buying one :slight_smile:

I made a version for my small tractor a steyr 9055

i am currently start this version need some work now

ag open gps lenkung v1

i also try to make a version for bigger tractor with metal reinforcement from hardwarestore.
and with different mounting options.

1 Like

I forgot is there anyway to get the messurements ? without its really complicated to get it right

I print one sample of plastic parts but never test with motor
An important point is to find an electric motor and adapt it

Finnaly i choose to do combination of steel and TPU95 :

  • to make combination of gear and friction
  • in case of emergency i will kill the small gear
    and after ( i think)
  • this concept like friction is more quiet
  • this concept is smaller and less hide the dashboard compare to plastic gear

After like AdreasTT or other plastic parts with 3D it is really fast and test
and no need specific machine

And also pleasure to make it and improve
Sorry but it is not my target to sell it, just share

1 Like

@ AndreasTT we run a 6210R and a 6930 here at farm. I intend to run AgOpenGps on both so I will take the measurements in the next days and come back, I do not have them yet.

Great! Thank you for sharing!

About the Quality of 3d Printed Parts, I think about 90% of the Cerea Users drive with printed ones, and if you use PETG and a resonable amount of perimeters, 6 is a good way to go, there is no Problem and the big advantage if something really breaks, you can reprint it within houers, i would definitly try it out Julien.

If you have further Questions there is a Telegram Group for autosteering on John Deere: Telegram: Join Group Chat
and one for 3D Printing for steering Mounts and Gears in general: Telegram: Join Group Chat

And here’s a Picture of the printed Gears on a JD 6230 Premium from the german Cerea Forum
Ohne Verkleidung Zahnrad im eingriff

1 Like

Thanks for the letting me know. I do not understand German but fortunately Google Translate does a pretty nice job translating it into English.

Yeah and if you got any issues you can always ask in english, the Guys are very nice and will help you out :wink:

One thing that I do not really understand related to Cerea software is how come Cerea doesn’t need a wheel angle sensor. It does use an encoder on the DC motor but if you disconnect the motor from the steering wheel and turn the steering wheel and connect the motor back how does the software knows in which position is the steering wheel? Probably some complex code in the software or maybe torque measurement…

They must be estimating the zero wheel angle from the change of heading. Not at all equally accurate as a WAS reading. Trying to estimate larger wheel angles becomes even more inaccurate.

There are commercial auto-steer kits that do not have a WAS and one can often see how they wander like a snake when trying to reach the AB-line.

I have the idea of using an ordinary bicycle sprocket with a chain and using 3D printed parts as a bracket and adapter.
2 Possible problems:
Noise development may be a little too much

the bigger problem is to create a freewheel so that the motor can “unhook”

@ NorthernFarmer previously worked as programmer for industrial automation, in 10 years I only saw one time a control loop PID with a calculated (estimated) process value (feedback) instead of a true process value (like WAS) … it was highly unreliable … I’m guessing the only way to implement such a control loop without a true feedback is what I suppose John Deere has implemented in ATU 200 / 300 where you replace completely the steering wheel with the ATU so the system knows at all time where you are with the steering wheel …

@ AndreasTT that’s a nice idea … it could definitely prove to be more reliable than plastic … on the safety side I wouldn’t want to interfere with my fingers in a bicycle sprocket :slight_smile:

Yeah I am working right now and i need to design a cover around it its possible but a little bit tricky

So how does JD or Trimble know the steering angle from the steering wheel all the time when the orbitrol leaks?

Yes I agree that the ATU position sensor must be used for a wheel angle estimate but it is only an estimate because of the drift. These auto-steer tools can be equipped with a WAS but please explain how do they obtain a “true process value” from the ATU when no WAS is installed?


I once created a concept design as I imagine.
The orange ring is supposed to represent the chain run.
Some fastenings and tensioner system are still missing …

Parts used:
Shimano 32 tooth sprocket (since it has a large opening, other sprockets have similar sprockets)
2 standard tensioning wheels
1 small wheel with 11 teeth (only one placeholder is missing)

ag open gps steering wheel v3 bycicle v1

1 Like

Agreed. For the JD ATU it’s not a true value meaning the wheel angle position, however oposite to Cerea for eg it’s the best possible estimation without WAS using the steering wheel rotation. For Cerea as I could actually disconnect the motor from the steering wheel while using it, the encoder would probably maintain last known position so I would be very interested to know which calibration is the software performing when you connect the motor (encoder) back so that it knows what is the steering wheel rotation.

Me too would be interested to know about the actual implementation for both Cerea and JD (and similar) but I don’t see why the two would need to be different. Both need some adaptation/estimation, Cerea may just have a bigger uncertainty to start from.

There are members on board who have used Cerea. Perhaps they can tell if it prefers the tractor aligned to the A-B line to make the start smoother?