Steering angle 4wd switch

[clbarclay]

I want to make the 4wd to disengage with steering angle on a JD 6600. As standard its either on permently or off and on with the brakes. A low lead ratio and tight lock means it scrubs wide with 4wd engaged on the headlands and at the moment I could do with another arm for headland turns.

I would apreciate any advice and experiance on making and fitting steering angle switches.

For wiring it in, I am thinking of putting a two pole switch into one of the wires to the 4wd switch so I can select normal 4wd or via the steering switch to make and break the circuit. Does anyone have a wiring diagram they could share or know which wire to insert the switches to?

 

[Mursal]

You need a reed switch on the steering ram? As the magnet passes the switch the power is supplied to the 4WD hub to disengage it? But it will need to toggle (stay on) until the magnet passes the switch again, on the way back? Does this make sense?

 

[clbarclay]

What happens when the steering is turned tight enough for the magnet to work the reed switch, but then the steering is straightened up before the magnet goes past the switch?

I was thinking of either a cam working a switch or sprung linkage to a switch like the combine has for telling the yeild monitor when the header is down. Either on the ram or at the hubs. I hadn't thought about a non contact switch, which would probably eliminate wear and tolerate dirt better.

I vaguely recal an angle disengage in a practical farm ideas years ago, but I don't know what manufacturer have used.

 

[Lincsman]

Switch off a NH TM?

 

[Mursal]

But, can you not place the magnet so it switches on the tight angles, both left an right? I thought it, the most likely place to get accurate switching, or maybe not?

 

[clbarclay]

Reed might well be the way to go. Induction switches would be precise and work of an easily tweeked cam profile, but also unncesiserily complicate it, needing a power supply. If the magent moved too far past the switch I could just add more magnets next to each other.


I will try and take a look at a TM. Which other model tractors had it fitted?

 

[mayos]

Most Deutz product have it.

 

[DrDunc]

Does it have swiveling mudguards? A normally closed switch between the mudguard bolt and the stop and you've got your position sensors. When contract is made the switch goes open, breaking the circuit.

To wire it I'd cut the switched wire from the 4wd. Then put in a double pole toggle switch in. With the new switch, for constant 4wd power will pass through from the output of the tractor 4wd switch to the original wire that's been cut.

For intermittent 4wd the toggle switch puts the output from the tractor 4wd switch into the wiring for the normally closed switches on the mudguards. The output from the mudguard switches is connected to the cut wire that came from the tractor 4wd switch.

The wiring of the normally closed mudguard switches needs to be in series. This means a wire from the toggle switch goes to one side, the output of that switch connects to the other mudguard switch, and then the output goes to the cut tractor wire. Thus either switch going open will break the circuit and stop power going from the tractor 4wd switch to the cut wire.

Hope that makes sense. If not I could draw the circuit and upload a picture of it.




The sensor on Deutz axles is a rotary pot internal to the axle so is unlikely to be suitable.

 

[clbarclay]

Unfortunately it has fixed mud guards, but switches on the chassis rails being triggered by the mud guards may work.

 

[Bloders]

I have used a brake light switch and a spring of a 590 kind of thing. mine is to switch on sprayer and stuff but same idea.
Wire in as drdunc, though ewe could fix end of spring to track rod end and put switch on axle. as ewe turn, spring is pulled and that works the switch iykwim

Drdunc, not sure why you say double pole switch??

 

[davedb]

a headlight relay may help you on this job, you could have a magnet on the axle as said above this would send power to the relay when the steering passes the set point and then when it passes again it would send power again and switch the relay off if that makes sense?

 

[DrDunc]

......

Drdunc, not sure why you say double pole switch??

Should've said double throw

But even that's probably not the correct name! One input that switches between two outputs, sort of thingy

 

[reb1952]

Its one of those situations where off the top of my head I couldn't remember what the correct technical term is, but I knew what you meant, after all I made the same mistake in the original post

Lack of rain halted drilling again, so will have a tinker tomorrow and work out which wire insert a double throw switch into.

I have used a brake light switch and a spring of a 590 kind of thing. mine is to switch on sprayer and stuff but same idea.
Wire in as drdunc, though ewe could fix end of spring to track rod end and put switch on axle. as ewe turn, spring is pulled and that works the switch iykwim

Drdunc, not sure why you say double pole switch??

That must be a very talented sheep


Edit: sorry just released I posted this on my fathers account (family PC) rather than my own (clbarclay)

 

[defender]

use an On/On switch to fit in the 4wd feed ,fit one side to work the original and the other diverted through a reed switch operated by a bar magnet of the desired length so that it drops the power to 4wd when the switch moves out of range of the magnet
keep it simple

 

[Bloders]

use an On/On switch to fit in the 4wd feed ,fit one side to work the original and the other diverted through a reed switch operated by a bar magnet of the desired length so that it drops the power to 4wd when the switch moves out of range of the magnet
keep it simple

I think this is best as there are no external moving parts to get filled with dust.

 

[Mursal]

Where are you going to get a reed switch that will have contacts big enough to control the 4WD solenoid, or are we fitting a relay?

 

[defender]

do the 4wd signal wires not go to a relay already ? I don't have a wiring diagram for the tractor in question .Solenoids don't draw a huge amount of power though and 5 amp reed switches are available and if that's not big enough a relay could be fitted though or change the Reed switch to a proximity switch . A limit switch is another option