Beagle123
10 kW
Here's my problem:
I building a electric scooter using a CVT transmission (pictured below).
If you aren't familiar with CVT's look at this animation:
http://auto.howstuffworks.com/cvt2.htm
So I bought this CVT from ebay, and I tested it by using an electric drill to spin the drive wheel. I wanted to spin the drive shaft fast enough to activate the pulleys, making it "shift gears." However, my drill wasn't fast enough. The CVT works by centrifugal force, so when the RPMs get high enough, it will start adjusting its gears. My drill says, "2700" RPMs on it, and it was probibly working at about 2400 RPMs, which wasn't sufficient.
You can see a video of this test attached below. ALLOW SEVERAL MINUTES TO DOWNLOAD.
This transmission was made to fit a x8 pocket bike. So, I researched the x8 on the internet. I found out that the engine can go up to 8000 RPMs (really more like 7000 with load)
So, I need to get a motor with very high RPMs.
Most scooter motors run at about 2800-3000 RPMs, and gearing them down is usually the problem. But I need more RPMS.
Then I found these Mag Motors:
http://www.battlekits.com/robot_motors.htm
The stats are truly unbelievable: Aparently they have a motor that's 83% efficient and puts out 3hp and weighs 4lbs. Another is 4.5hp, 84% efficient, and 7lbs. And both at 24V!!
Does anyone know anythiing about these motors?
Here's what I want to do:
I want to use 4 lead acid batteries at 17ah each to make a 48v system. I want to use a 50amp controller like thiis:
http://www.tncscooters.com/LB37.php
So, I need a motor that will operate at 6000-7000 rpms under maximized conditions. When its running that speed, it should be producing perhaps 1.5hp.
My question is: will I be able to achieve these types of RPMs without pumping 100+ amps into the motor? Do I want to use the smaller motor, so I get less torque and more RPMs? Do you think the samller motor will fry? (4lbs). Does anyone know of a better solution?
The way I see it, motors are pretty simple: If you pump 20 amps @ 48v into a motor, you're providing 960 Watts of power. Since the motor is 80% efficient, you should get 768 watts out of it. But those 768 watts can take many forms-- it could be a slow moving shaft with lots of torque, or a fast moving shaft with less torque. In my situation, I need the faster one.
Right now, I'm leaning toward the idea of getting the larger, S28-400 motor, then increasing the volts and amps until I get the needed RPMs. I'm afraid I'll be going 80mph before I'm done! I really don't want that. I want a 30+ mph scooter that just humms along, and takes the hills at about 20mph (but easily!)
Thanks, you guys rule.
I building a electric scooter using a CVT transmission (pictured below).
If you aren't familiar with CVT's look at this animation:
http://auto.howstuffworks.com/cvt2.htm
So I bought this CVT from ebay, and I tested it by using an electric drill to spin the drive wheel. I wanted to spin the drive shaft fast enough to activate the pulleys, making it "shift gears." However, my drill wasn't fast enough. The CVT works by centrifugal force, so when the RPMs get high enough, it will start adjusting its gears. My drill says, "2700" RPMs on it, and it was probibly working at about 2400 RPMs, which wasn't sufficient.
You can see a video of this test attached below. ALLOW SEVERAL MINUTES TO DOWNLOAD.
This transmission was made to fit a x8 pocket bike. So, I researched the x8 on the internet. I found out that the engine can go up to 8000 RPMs (really more like 7000 with load)
So, I need to get a motor with very high RPMs.
Most scooter motors run at about 2800-3000 RPMs, and gearing them down is usually the problem. But I need more RPMS.
Then I found these Mag Motors:
http://www.battlekits.com/robot_motors.htm
The stats are truly unbelievable: Aparently they have a motor that's 83% efficient and puts out 3hp and weighs 4lbs. Another is 4.5hp, 84% efficient, and 7lbs. And both at 24V!!
Does anyone know anythiing about these motors?
Here's what I want to do:
I want to use 4 lead acid batteries at 17ah each to make a 48v system. I want to use a 50amp controller like thiis:
http://www.tncscooters.com/LB37.php
So, I need a motor that will operate at 6000-7000 rpms under maximized conditions. When its running that speed, it should be producing perhaps 1.5hp.
My question is: will I be able to achieve these types of RPMs without pumping 100+ amps into the motor? Do I want to use the smaller motor, so I get less torque and more RPMs? Do you think the samller motor will fry? (4lbs). Does anyone know of a better solution?
The way I see it, motors are pretty simple: If you pump 20 amps @ 48v into a motor, you're providing 960 Watts of power. Since the motor is 80% efficient, you should get 768 watts out of it. But those 768 watts can take many forms-- it could be a slow moving shaft with lots of torque, or a fast moving shaft with less torque. In my situation, I need the faster one.
Right now, I'm leaning toward the idea of getting the larger, S28-400 motor, then increasing the volts and amps until I get the needed RPMs. I'm afraid I'll be going 80mph before I'm done! I really don't want that. I want a 30+ mph scooter that just humms along, and takes the hills at about 20mph (but easily!)
Thanks, you guys rule.
