Drivetrain for high-torque agricultural rover

I’m not sure if this is the right place for this question, but I’m wondering if anybody has suggestions for a drivetrain for a higher-torque agricultural rover (skid-steer, ~2000W total power, 2 mph/3 kph travel speed). To get used to the Ardupilot, I built a much smaller rover, but am realizing scaling up the power is going to be a challenge. My first thought was to use two Flipsky 5065 motors (270KV, 80A per motor), but I’m having a hard time finding a gearbox that is compatible with the high torque from the motor (4Nm out of the motor) that would help me go from ~3200 rpm at the motor to ~26 rpm for the wheel. Any thoughts? Should I try to move away from electric motors and try to find a suitable hydraulic motor instead?

Thanks in advance,
Ryan

Just a suggestion, you might go look at the parts lists for the electric riding mowers and find the gear motor they’re using. If you can dig up a part number, chances are you can find replacements on eBay or elsewhere.

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I don’t have the answer, just posting to request further details on your project! :slight_smile:

(I am building a small spraybot, for which 2x RS-550 motors are adequate)

Hi Peter,

My goal is to build a smaller rover with a 5’ working width, which I’m hoping will be able to plant and manage small grains up until harvest. Still playing around with different components and configurations, but it would need a good amount of power for openers at planting (I’m looking at a modified hoe-type opener, since it doesn’t need the down pressure of a double disc). I think I got around the torque/drivetrain problem by going from 4 larger wheels to 6 smaller ones (smaller wheels should need less torque to power them, and the 6 wheels should help share the load a little assuming I can keep them all on the ground). I also think I can reduce the draft force a little by using a narrow opener and keeping planting depths shallow. So really I avoided the problem instead of fixing it…

If I get a working rover, I will definitely share pictures here!

Glad to hear you’re working on a similar line! Out of curiosity, where are you based? My hesitation with a spraybot is I don’t know if my local (Oregon) pesticide application regulations would allow an unattended rover applying pesticides. Are you looking at selective spraying of weeds, or spraying a full field?

Ryan

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Thanks Ryan- cool project, look forward to the photos! Maybe a little version of the JD? :slight_smile:

image

I am based in England. The spraybot will be selective spraying based on video camera feed to a neural network classifier. The spray resolution is ~30cm x 30cm (1’) and I expect <1% of the field will be sprayed. It would just be replacing human spot spraying with a low volume tank (say 15l). I had not considered regulations to be honest. Given the model is trained on human-labelled photos and >95% accurate I’d try to argue it’s equivalent to spot spraying. Also, even if the robot needs to do one pass for data gathering/mapping (with GPS RTK) and another after positive hits reviewed by human it would still save time.

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Sorry about the late response- similar function to that rover, but nowhere near the working width or HP. Hopefully I’ll have a photo to post soon!