Hesston swather angle sensor

Here is a picture of my wheel (valve) angle sensor . Should work for any swather with this type of valve.

Does not steer too bad at all.


Wheel motor mount
Screenshot_20210802-224108_Samsung Internet


What are the rest of your settings?
Vehicle type choice, combine?
Tuning parameters?

I know they will not be perfect for me, but at least it will be closer to start.

About to do this to two MF swathers, little different setup but close enough.

Combine for sure.

Counts per degree is pretty low, like 31.
Gain or P is at 80 i think. Didn’t take a picture. Min is at 0 and low at 20 is or even lower.
I just made a regular turn , like you would with a swather, and used that for my steering angle, otherwise you’d end up spinning too much. I think I need to install a wheel angle sensor that has a higher resolution, since a half turn is enough to turn the swather but you can do 2 fullt turns on the steering wheel to either side.

It works better in pure pursuit than Stanley I found, couldn’t get it stop wondering back and forth over the line.


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I’ve wondered if there was a way to figure out what the steering ratio is at different speeds, and thus what the virtual steering angle would be based on the steering wheel position. But what you’ve done seems to work well enough. How slow can you go before you start having problems? Sometimes I have to go less than 2 mph. EZ-Steer is mostly okay with that if I turn the agressiveness down a bit and live with some wandering.

Slow works good in pure pursuit. It’s getting tricky when you go faster. Like over 5 mph. Stanley was weaving back and forth, pure pursuit was doing pretty good. I turned the max rpm quite a bit down, but then the swather would not do a line jump nicely. Swather steering is quite sensitive, for the Hessont at least. I think the reading frequency and sensor resolution needs to to be quite high for this setup / type of machine. Maybe a linear sensor would be a better choice. Or incremental sensor on the steering wheels, since there I no slippage like an orbitrol would have on a tractor or combine. If I could find a way that I could get the full working range of the senor for only one turn to the left and right I think it would be fine. But the steering wheel can do more turns, so the linkage would be damaged whe you turn it too far…

Need to put the engineering hat on. Have ideas, but no time.

You could build something with springs on each side that keep the arm following the steering valve, for one turn to each side, once you go over that the sensor is in max position, and the springs would just get elongated. More than one full turn to each side would never occur on a swather while working / swathing. I think.

You need to move the sensor up the arm, the length from swash plate pivot to the linkage arm needs to be the same as the the swash plate pivot to the sensor shaft (not the linkage pin like you have it).

Because now as you have it as you go faster the centre or zero moves.


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The distance between the arms only changes when you steer left or right. Going forward and backward will move both arms the same distance. The centers of the rod between both arms is lining up with the bolt holes of the arms. The reason why it’s moved up so far is to utilize maximum sensor range.

Maybe reducing the counts per degree even more and increasing the aggressiveness might help. Need to do more testing.


Forgot to take into account the sensor is rotating too, so even as the distance changes the sensor angle is the same.

If you turn the sensor bracket around so it’s over the grease nipple your resolution will be higher when turning or is it too much?

The current setup uses the full sensor range.

Couldn’t really find any specs on the princess auto sensor, seems to work fine with a regular steering setup. I might use a incremental encoder since its not limited by travel.

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I am very interested in what you find out with the incremental encoder vs an absolute 1-5v sensor.

I will be giving this 1-5v sensor a try,

It is a totally different situation but the way I fine tuned a sp sprayer was to steer it manually following a line and watching the steering chart, and then adjusting the settings to get the set point to react the same as the manual steering. It was easy to tune it in travelling slowly but at working speeds it wandered everywhere

An encoder is not going to be just swap out solution, I realize. Have ro translate count signal into an angle for AOG.

I ordered a delphy sensor from Rockauto, it has a wider range compared to the princess auto sensor. I’d say 90 vs 120 degrees. I’ll try that when I get to it.

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Sorry for the delay. As promised. It does a better job in PP than Stanley .
U-turn works only in PP.


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Thank you for the information.

Still waiting for the sensors to arrive from china. But we are already in full harvest mode. So at least the field will be empty to tune them.

This year is hopefully the last making crooked rows in the swather.

What I will try is a motor with lower rom though, then you might not be at low end of every thing in the settings. Like the 192rpm motor from phidhets. But you are right harvest is about to kick off here as well.