Hello! I am looking for advice on a motor/gear system that could propel ~200lbs of kayak and gear up fairly steep trails at moderate walking speed. I found a motorized wheelbarrow system called a PAW (https://www.electricpaw.com/paw.html) but I am hoping I can make something smaller/lighter that can be stowed inside the kayak while not in use. Additionally something like this will likely be under powered. Guidance appreciated!
Here are some estimates I received from the motor sizing tool
Input
- Total mass: 90.7
- Number of drive motors: 1
- Radius of drive wheel: 1
- Robot Velocity: 4
- Maximum incline:15 [deg]
- Supply voltage: 24 [V]
- Desired acceleration: 0.2
- Desired operating time: 20
- Total efficiency: 65 [%]
Output (for each drive motor)
- Angular Velocity: 4.0000
- Torque*: 116.49
- Total Power: 465.98
- Maximum current: 19.416[A]
- Battery Pack 6.4719 [Ah]
That’s quite a beefy motor you need. Consider an adult male can weigh 200 pounds, and electric scooters often struggle going up hills with a single rider. You indicated “fairly steep”, but put 15 degrees - just want to ensure that’s accurate, and 4m/s is pretty fast.
Also, it looks like under radius of wheel you kept 1 meter? It’s likelier to be 6 inches (12 inch diameter).
You also indicate one drive motor - can we assume it can pivot to give direction?
Upping the specs a bit gives 250rpm, 850kg-cm max continuous torque when moving 100kg up a 20 degree incline with a 6inch wheel.
The motor you linked to is not in the right ballpark. You need to be considering the same type (in terms of horsepower) of motor used in electric scooters. Although RobotShop does not offer that range of motor at this time, you can search online and get quite a lot of results which include a motor controller and other items (normally for manual control).
@cbenson, thanks very much for your reply. Your observations are spot on. I think I need to try to find something that will simply assist with the effort of getting my 100kg up the hill even if its slow. So perhaps an electric scooter system paired with a reduction box. I will see what I can find…