NW Wisconsin | Adrian - 5/17/2017 15:20
That's super cool. I assume that all rows got the same PWM signal, and you used relays to switch off the rows you wanted to stop? Assuming that all rows were recieving the same PWM signal, did you have any trouble with rate discrepancies between the rows? I.e. if one was significantly harder to turn than another, the same PWM signal might not turn it quite as fast...
That's really awesome. Hope you choose to share some more details of this project.
Adrian
Edit: Also, how many rows is the planter, and can you give us an idea how many $$$ you have in the project?
Adrian
You are right about all motors receiving same pwm. The pwm goes to a junction block and then out to all motors. But it is only used as a speed signal and does not actually drive the motor. There is a controller built into each motor that will read the signal and calculate proper speed.
As far as shutoffs, I take the 12v signal directly from fieldIQ and connect it to motors' enable pin. No relays required.
These ClearPath motors are designed for cnc controlled machinery. So they are way more accurate than the signal going into them from the gps. If I remember correctly from the instruction manual the internal encoder that tracks motor position is somthing like 12,800 counts per revolution. They are just stupid accurate.
They are externally powered with a couple 70v DC power supplies. So no big load on fieldIQ module. |
Homemade electric planter drive
