I am custom designing something and need servos to steer this giant rover.
I have seen 70 KG Torque servos out there.
What is the math behind over all weight vs. the torque need to steer the Rover?
Thanks
p.s came across this one https://www.pololu.com/product/1390
also the pic below…
For that price you could probably get a used set of 24V wheel chair motors and control your vehicle with skid steering. Check eBay for “wheel chair motors” and you can find a set closer to ~$150.
Regarding the math for torque needed to steer the rover, it really depends on how the servo is implemented. How are you intending on using it?
Thats a great Idea, but can it handle 200 lbs of weight?
I am designing a rover for lawn which will be like an all in one solution.
I’m using them on a lawn mowing rover that weighs close to that and they perform quite well. They’re used on electric wheel chairs and scooters designed to carry the weight of a person so I would say they’re perfect for your application if your rover will weigh about 200lb. Just my two cents though.
wow…nice work!!! How do you control it?
I am building something completely autonomous. I am trying to avoid building the power train system, the electronics needed etc.
Do you have a video of this baby in action. Nice workmanship!
I am taking an off the shelf electric cart and focusing on the autonomous part. My solution doesn’t cut the grass. It’s for after the grass is cut and how to maintain your lawn…fertilizer, weed control, arretating the lawn, line marking etc.
Here’s a video of it without the deck on. It’s got a Pixhawk in the enclosure on top and a Sabertooth 2X60 in a box on the back for controlling the wheel chair motors.
I too wanted to avoid building a robot from scratch, but the alternative is to spend a lot of time trying to integrate a riding mower or lawn tractor with electromechanical equipment that can communicate with the flight controller. Pick your poison, I guess. Building from scratch seemed the most robust way to get there to me.
@ktrussell put a lot of effort into getting some actuators to work on his zero turn mower and has he’s had really good success with it from what I’ve heard. He has a lot of posts here and YouTube videos of how he did it. He kind of convinced me to build from scratch, after seeing all the work that went into it 
This is an efficient and complex mechanical design. Nice work by you guys. barvo!!!
I personally think the autonomous part is the more challenging (for me, not mechanically expert). I am adding things like Weed recognition via vision.
I found one system and it took me one day to make it Rover off the shelf 
Saved me million of hours for sure. I will post some video next week once I am done.
My nephew works for Tesla, so he is calculating the toque I need to steer 200lbs. lets see what he comes back with tonight.
Here is a pic. This baby can handle 220lbs of weight. Cost me $499+ tax but saved me 1000’s of hours! (I hope so) or it will fall apart in pieces… ha
Drew, I just watched your video. Very nice! I have realized that eventually I would like to have a small electric autonomous mower to get into areas that are not very appropriate for the big zero turn I have now. I hope when get to the point, I can find your (and others’) work and learn from you!
I see your comment about my actuators. I guess you know that I swapped the linear actuators out for heavy duty servos with linkages to connect in a similar way that the linear actuators did. I still haven’t done a good video on that, but I have mentioned it around to some degree. I am using the Hitec D845WP. That was what @Kevin_Groba used before me with success.
