First off, let me say that I'm a total noob when it comes to designing and building an EV and may be totally wrong about any number of things. I welcome feedback on all aspects of this project.
I'm building an EV to carry 2-4 adults at 5 MPH on level but dusty ground. I've built some pieces of it for testing but mostly right now I'm working on the CAD model. It uses two 36v, 800w MY1020 motors and is set up for 4 wheel drive and differential steering.
Each motor has a 12t #40 sprocket that drives a 48t sprocket on a jackshaft, which has two 12t sprockets each driving a 48t sprocket on a front wheel and a back wheel, so 16:1 overall and about 6.5 MPH at 2700 RPM with 13" mini ATV wheels if I did my math right.
What's giving me the most trouble right now is that 48t #40 sprockets are big - almost 8" OD, leaving me with less than 2.5" ground clearance at best. It'd probably be digging into the dust as soon as there was any weight on it.
I'd like to replace the motors with gear motors, or add a gearbox, and get maybe a 6:1 reduction ratio before the chain drive. Smaller drive sprockets would let me keep everything within the frame and protected by a floor pan.
Trouble is, I can't find any 36v gear motors over 600 watts and I'm not aware of any add-on gearboxes that will work with these motors. I've already got the battery pack and charger, as well as a good brushed DC motor controller, so going to a higher voltage or brushless motors would probably be out of my budget. The other possibility I'm considering is to add a second jackshaft on each side to split the reduction ratio, but that's a lot of chains to mess with for a guy who's never worked with roller chain before.
Any suggestions? I've learned a lot from browsing minibike, kart, and ATV forums, but almost no one builds 5 MPH vehicles and most are going for speed.
Thanks!
I'm building an EV to carry 2-4 adults at 5 MPH on level but dusty ground. I've built some pieces of it for testing but mostly right now I'm working on the CAD model. It uses two 36v, 800w MY1020 motors and is set up for 4 wheel drive and differential steering.
Each motor has a 12t #40 sprocket that drives a 48t sprocket on a jackshaft, which has two 12t sprockets each driving a 48t sprocket on a front wheel and a back wheel, so 16:1 overall and about 6.5 MPH at 2700 RPM with 13" mini ATV wheels if I did my math right.
What's giving me the most trouble right now is that 48t #40 sprockets are big - almost 8" OD, leaving me with less than 2.5" ground clearance at best. It'd probably be digging into the dust as soon as there was any weight on it.
I'd like to replace the motors with gear motors, or add a gearbox, and get maybe a 6:1 reduction ratio before the chain drive. Smaller drive sprockets would let me keep everything within the frame and protected by a floor pan.
Trouble is, I can't find any 36v gear motors over 600 watts and I'm not aware of any add-on gearboxes that will work with these motors. I've already got the battery pack and charger, as well as a good brushed DC motor controller, so going to a higher voltage or brushless motors would probably be out of my budget. The other possibility I'm considering is to add a second jackshaft on each side to split the reduction ratio, but that's a lot of chains to mess with for a guy who's never worked with roller chain before.
Any suggestions? I've learned a lot from browsing minibike, kart, and ATV forums, but almost no one builds 5 MPH vehicles and most are going for speed.
Thanks!