This is a frame rescue, and I wanted an e mini bike that could climb any hill with enough traction. By the numbers:
Prime Mover:
BLDC, 48 volt, 20 amp in, 750 watts out. 2880 rpm @48 volts, reduced to 480 rpm. 14 tooth, #40 sprocket. Output torque after 6/1 gear reduction, ~11 ft*lb.
BMI Jackshaft, with 14 tooth, #40 sprockets in and out.
NuVinci 171 Developers Kit, Auto Transmission:
27 tooth input sprocket, 44 tooth output sprocket. When motor output increases to 350 rpm (approximately 3 mph), the auto trans changes gears in 64 steps, maintaining the output motor gear reduction speed of ~350 rpm, to ~10.5 mph. Controller is preprogrammed for this, and speed is sensed from the speed sensor installed on the disc brake. Actuator is originally from a Ford automatic window opener, and moves the ceramic balls into and out of the visco-elastic fluid to effectively change gear ratio.
Transmission torque rating, 48 ft*lb, input. Max required, ~21 ft.*lb.
Transmission rotational velocity limit, 1000 rpm. versus maximum required of ~500 rpm.
Rear sprocket, 60 tooth, #40.
Rear tire, 8", with effective radius of ~7.25"
Battery: 720 watt hour, 48 volt, Cal Bike
Rear brake - disc, via the drive chain, from the NuVinci transmission
Front brake, drum, via a "pay it forward" benefactor, from Old Mini Bikes.
Front light - rescue, from 12 volt Night Ryder with bad battery
Right chain guard, modified trash can top
Left chain guard, modified refrigerator shelf.
It will go for over 14 miles in South St. Louis, and winch over 200# up any gravel hill (i.e. it will lose traction before stalling out). Top speed ~13.5-16.5 mph, depending on state of charge. Vids will be posted after nieces/nephews shake it down in the country, during annual 4th of July family reunion/fluids replacement event....
https://www.youtube.com/watch?v=AWEJPqJtZsk
Prime Mover:
BLDC, 48 volt, 20 amp in, 750 watts out. 2880 rpm @48 volts, reduced to 480 rpm. 14 tooth, #40 sprocket. Output torque after 6/1 gear reduction, ~11 ft*lb.
BMI Jackshaft, with 14 tooth, #40 sprockets in and out.
NuVinci 171 Developers Kit, Auto Transmission:
27 tooth input sprocket, 44 tooth output sprocket. When motor output increases to 350 rpm (approximately 3 mph), the auto trans changes gears in 64 steps, maintaining the output motor gear reduction speed of ~350 rpm, to ~10.5 mph. Controller is preprogrammed for this, and speed is sensed from the speed sensor installed on the disc brake. Actuator is originally from a Ford automatic window opener, and moves the ceramic balls into and out of the visco-elastic fluid to effectively change gear ratio.
Transmission torque rating, 48 ft*lb, input. Max required, ~21 ft.*lb.
Transmission rotational velocity limit, 1000 rpm. versus maximum required of ~500 rpm.
Rear sprocket, 60 tooth, #40.
Rear tire, 8", with effective radius of ~7.25"
Battery: 720 watt hour, 48 volt, Cal Bike
Rear brake - disc, via the drive chain, from the NuVinci transmission
Front brake, drum, via a "pay it forward" benefactor, from Old Mini Bikes.
Front light - rescue, from 12 volt Night Ryder with bad battery
Right chain guard, modified trash can top
Left chain guard, modified refrigerator shelf.
It will go for over 14 miles in South St. Louis, and winch over 200# up any gravel hill (i.e. it will lose traction before stalling out). Top speed ~13.5-16.5 mph, depending on state of charge. Vids will be posted after nieces/nephews shake it down in the country, during annual 4th of July family reunion/fluids replacement event....
https://www.youtube.com/watch?v=AWEJPqJtZsk
Attachments
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E Mini Bike 750 watt, 48 volt BLDC Motor.jpg48 KB · Views: 2,345
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E Mini Bike NuVinc Transmission with input and output sprockets and chains.jpg54 KB · Views: 2,345
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E Mini Bike with Disc Brake and trans controller and 48 to 12 volt controller.jpg60 KB · Views: 2,346
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E Mini Bike with NuVinci Trans Actuator.jpg61.4 KB · Views: 2,346
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E Mini Bike wth NuVinci Transmission and Cal Bike Battery.jpg62.4 KB · Views: 2,346
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E Mini Bike wth rear basket.jpg67.6 KB · Views: 2,345