Hi rikko. They were VERY guarded when I mentioned any steering modifications that weren’t what I would describe as proprietary systems. The suggestion I got was to replace the Danfoss orbital unit with one with built in PWM valves. I’ve no idea of price or how it compares price wise to the valve system that is being discussed.
My 936 is autosteer ready and so has can bus controlled Danfoss valves fitted. They could supply me with the appropriate Danfoss PWM valve head to replace the CAN bus part.
here a message from Christian:
"Hello, at the certification level I phoned fluid-system who confirmed that they never asked this question and that it did not concern them.
In my opinion, the valve installed alone without electrical connection should at least be approved. A processed and unapproved tractor is simply not
more insured in case of accident. In these conditions I prefer to take original valves even if they cost me 800 Euros more.
I also think it would be okay to tell everyone that their tractors will no longer be approved on the road, and then it will be up to everyone to decide.
For me the solution will be that Jean Marc sees at inov gps how much it would cost to equip an additional tractor with a hydraulic valve and then negotiate the 20 parts.
Then we can at least say that if we go on the road we just unplug the connector and everything is certified.
Hello Alan,
Here in France,could be a problem also.
Here is a web site with prices with Danfoss electroproportional orbitrols : https://www.holsteinhydraulik.de/en/c/steering-units/electrohydraulic-p
A 100 or 125 model (with ot without load sense) could fit a 120 kW tractor.
It’s SIL2 appoved equipements with PWM, CAN J1939 or CANOpen command
which is not a big issue to control.
For my MTX150 I look at this solution but don’t know if there enough space
for PVED, And hoses are not exactly at the same position.
If someone has done this upgrade on CASE or McCormick, I’m interested to know ?
francois
Thanks Alan
Mine is a 4220 Fastrac, which has a valve fitted, but will of course be CAN bus too. To be fair Charles Quick suggested replacing the valve head with a PWM one if I could find one, but I went the Hydraforce route as it seemed easier. Fitting on the power beyond, and putting lock valves in the two pipes to the steering ram would make it safe, I assumed! I would think a complete valve from JCB or Fendt would be a small fortune.
If you could get the replacement head however, that sounds good. Did they give an indication of price for that ?
I had been looking through these units with interest. As I said, my 936 already has a Danfoss autosteer unit fitted and I’ve gone down the motor route with my 716 for now.
Edit: now with quote!
I use a 6/2 valve to do the trick. Unpowered = normal steering, and powered = autosteer. I use IBT-2 so easy with power from L-en pin (and via relay 12 v to valve)
With this setup, if L-en was powered accidentally, or if the valve stuck, what would be the outcome? Just wondering.
I have studied the valve arrangement schematic on my 936 and there seems to be several differing levels of fail safety built in. Even with jamming valves, the LS line from the orbital will allow operator steering to bypass the system. It’s an area of huge implications if any user modifications fail. Even cutting into steering hydraulic lines could be an issue legally?
A very good friend of mine was involved in a fatality accident over a year ago. The police took his tractor and inspected it meticulously. They had it for 7 months!! Luckily it was fine but a steering modification could have had grave implications.
You are right faults can happen even on original factory mounted systems, that is why startup screen tells you NOT to drive on road with system activated = no power to the ecu and valves.
The Tractor I drive at work has dealer mounted autosteer, and if by accident (broken wires near power leads) and +12V goes to the shift valve in the autosteerblock, I would be heading off the road.
Stuck valve would not be a problem in my case, because I would not be able to get off the field!
My system require A: Turn on switch to activate power to both PCB and relays for valves and IBT_2
B: turn on autosteer (not posible over 20 km/h)(and only IF I forget to flip switch to off
Wires rubbing its way to 12v is possible, just as for dealer mounted systems, but have to be wires after the last relay, because it is very unlikely that both the 5v relay (that has no power) and the following 12 v relay (also without power) should both fire up by themselves.
Suppose even injecting can codes or changing heads for pwm and installing own wiring, could have legal implications!
That’s why aogopen is not to be used on any machine!!! On your own legally.
I could never find any hydraulic schematic about Trimble valve used for NH and other. I found Fluidsystem that seems very well designed: could fit for all types of hydraulics, open and closed center, LS static and dynamic, safety thanks to selecting valve with orbitrol priority, pressure sensor to detect steering by hand action…
(I have no commercial relation with this company!!)
Curious to see why and how Trimble wants to use counterbalance valve?
Driving hyd valve with CAN looks “modern” but it is only possible with CanBus installed… AOG Arduino based will prefer PWM drive! easy and cheap…
Danfoss is offering CAN steering (OSPE)…Sometimes installed in tractor when"GPS ready". I saw (less popular!?) EHPS (with PVE solenoid PWM)Will not be easier to install as Fluidsystem…
This is the full hydraulic schematic of an early Fendt 936 (probably several other makes too) . The valves system is Danfoss and the main valve block, containing the proportional valve (top left) can be changed from can bus to PWM control very easily. MVLE1 & 2 are standard solenoid valves. Assembly DDFL is just a rotary swap over for reverse drive.
If all this is already installed on your tractor, you are lucky!
So PVLE (top left) was Canbus type! (surprised) if true then PVE to be replaced as PWM…
