Minpwm looks too high? It should be set just below it starting to drive the motor. Use drive mode, set it to zero so it won't move at all and then bring it up until it starts turning. Then back it down 1.
AgOpenGPS RTK Autosteer, How to Guide for £1000
- Thread starter Andy26
- Start date
Larel
Member
Point noted about being in the cab. The ball joints and steering linkage are all tight and the tractor steers dead straight and steady in straight line. Its only unstable when executing the turn.
clbarclay
Member
- Location
- Worcestershire
What is the WAS geometry like?
Could it be that the counts per degree isn't so accurate at greater angles compared to straight ahead.
Could it be that the counts per degree isn't so accurate at greater angles compared to straight ahead.
Larel
Member
Last night I was chatting to a retired electrical engineer and he suggested maybe the WAS output wasn’t linear at extreme angles which initially I took to be the WAS sensor angle to output being nonlinear, but what he meant was that it could be a mechanical issue, with the geometry causing a non linear output ie tractor wheels straight ahead 1 deg movement of the wheels will give one voltage change and when the wheels are at full lock a 1 deg movement will give a different voltage change.
davidroberts30
Member
- Location
- pembrokeshire
this is 1 of the reasons i went for a linear sensor
clbarclay
Member
- Location
- Worcestershire
Just how learer though is the relationship between rotating angle of the wheel and movement of a linear sensor?
My eyeball observation of tractor steering with a central ram is that the wheels turn more for a the same movement of the ram at the extremes of steering lock than they do when the wheels are straight ahead.
Some of the WAS linkages I've seen do look very likely to be very non linear compared to others, but tbh fine accuracy of the steering during U turns isn't that critical to most of us, so long as it is reasonably consistent and stable enough.
My eyeball observation of tractor steering with a central ram is that the wheels turn more for a the same movement of the ram at the extremes of steering lock than they do when the wheels are straight ahead.
Some of the WAS linkages I've seen do look very likely to be very non linear compared to others, but tbh fine accuracy of the steering during U turns isn't that critical to most of us, so long as it is reasonably consistent and stable enough.
- Location
- Northumberland
I'm not 100% sure about this. Near full lock a cm of track rod movement will generate more degrees of wheel turn than the same at straight ahead.
I still think the purest measurement of angle of turn is the OEM-style of direct recording at the hub. Whether 'mathematically pure' is best in practice is another matter. I'm using an OEM sensor on an MF over canbus, but haven't got out of the yard yet. Plan to do a retrofit WAS on a NH in the months to come.
clbarclay
Member
- Location
- Worcestershire
The in hub sensor on its own isn't perfect either as you have Ackermann effect to consider. AOG has had a setting for years now though to compensate for that issue.
davidroberts30
Member
- Location
- pembrokeshire
agree but the movement is the same both ways and there's no messing mounting a linear on the steering ram
you have to be fairly accurate in mounting a rotary sensor
davidroberts30
Member
- Location
- pembrokeshire
Have you done the wizard?
Larel
Member
To the best of my knowledge yes………., but my knowledge has a poor!
- Location
- Shropshire
So I’ve got everything setup, but my system can’t seem to detect any com ports as shown in the first photo? Ive got reading to the WAS and antenna but nothing from the steering motor.
Could just be me being daft so wonder if anyone can point me in the right direction?
the good news is I’ve got RTK signal , and have been using it as a lightbar for spreading fertiliser on grass, which has already made my life easier.
Could just be me being daft so wonder if anyone can point me in the right direction?
the good news is I’ve got RTK signal , and have been using it as a lightbar for spreading fertiliser on grass, which has already made my life easier.
Follow this - no COM ports needed:
was it not accurate enough in Single Mode for fert spreading that you needed the RTK correction data, or did you just go for best practice.
hollister
Member
- Location
- Alcester, warks
Its really no extra effort if you have a base station in range
Setting up autosteer on another tractor, I’ve the wee motor and plastic cogs all on, but fearful of little fingers.
I have came across a John Deere ATU that’s for sensible money, is it easy to convert to AOG I seen a post by @andyinv on the other forum but you didn’t seem to get it all going?
Will upgrade to Baraki in a while but this is about 1/3 price of a valve.
Robert
I have came across a John Deere ATU that’s for sensible money, is it easy to convert to AOG I seen a post by @andyinv on the other forum but you didn’t seem to get it all going?
Will upgrade to Baraki in a while but this is about 1/3 price of a valve.
Robert
yes if base station is nearby. Im just wondering how much GPS single would be expected to vary every 15mins as I drive around and around the field fertilizer spreading.
About 15-20cm, perfectly ok for fert spreading or cultivating.