# Society of Robots - Robot Forum

## Mechanics and Construction => Mechanics and Construction => Topic started by: RITESH29 on February 11, 2012, 09:45:29 PM

Title: How to make gear for electric car ....??
Post by: RITESH29 on February 11, 2012, 09:45:29 PM
Hi,

I am working on gear mechanism for controlling the two wheel at back of car with two DC motor of 24V .5HP......
so, no load RPM is 3000 i want to drive 15inch diameter wheel the front wheel are free. the required speed will be ~1meter/sec. not so fast
and RPM OF wheel at 100.

please help with these gear as worm have been constructed but the output at wheel is at 60RPM torque is very very less for driving the load of ~80kg.
Title: Re: How to make gear for electric car ....??
Post by: Soeren on February 12, 2012, 12:08:39 PM
Hi,

I am working on gear mechanism for controlling the two wheel at back of car with two DC motor of 24V .5HP......
so, no load RPM is 3000 i want to drive 15inch diameter wheel the front wheel are free. the required speed will be ~1meter/sec. not so fast
and RPM OF wheel at 100.
A 15" wheel at 100 RPM will go ~2m/s

please help with these gear as worm have been constructed but the output at wheel is at 60RPM torque is very very less for driving the load of ~80kg.
What is the loaded speed of the motor?
The unloaded speed doesn't say much, except that the gear ratio must be higher than 30:1, but not how much higher, so you need to find the loaded speed.

The two motors have 1hp total. In DK, a moped is limited to max. 1hp and 30km/h, with an adult rider and that's a bit over 8m/s, so you have ample motor power for 80kg at 1m/s (or 2m/s for that matter).