Geared Motor or Direct Drive?

[mailus]

I am doing a mini project on LINE FOLLOWING ROBOT. I designed pwm control using H bridge arrangement using Transistors. Everything is fine but the motor is not moving with load (around 750 Gms). i directly connect the motor with wheel without using any Gear.
i am using 3V supply from Coin type cell CR-2022.

is it possible to directly drive a wheel or use a geared motor?

i want to design a miniature line following robot.
Any suggestion to correct the problem........

 

[ArNvC]

Hi,
Look at your application of the robot. If it requires no speed or torque changes between the motor and the wheel, go for direct drive. A geared drive's torque can be increased by driving a larger gear with a smaller gear. In this case, speed will be reduced. A small gear can drive a larger gear to increase speed and decrease torque. What kind of motor you are using?

 

[mailus]

i buy it from local market. ordinary DC motor that withstand supply voltage up to 6 V.

i want the entire unit as miniature and i need speed also.....

 

[ArNvC]

If you have the circuit, go for it. I think still if you cant drive the wheels, try to reduce their size. Go for a simple and light chassis design. In all ways, try to reduce the weight of the robot to safely drive it. Just turn it around to see if the motor is ok and is rotating well. If everything is allright, reduce the weight (i.e. try to fine tune the mechanical design a bit)

 

[mailus]

i think my motors are weak to drive.because when i hold the shaft the motor will stop.so i need mini geared motor.......is it possible to get mini geared motor in india.

 

[chuckey]

your battery is far too small. - Have you measured its terminal voltage when the motor is running. For a load of 750 gms I would think you need either a 50 :1 gearing on a 3 V 50mA motor, for direct drive you would need a couple of watts at least 3V @ .6 A.
Frank

 

[Audioguru]

Nobody makes a CR-2022 battery. Maybe you have a CR2032 battery?

A CR2032 coin battery is designed for a continuous 0.19mA load which is almost nothing.
Its datasheet shows its voltage dropping to 2.4V with a 28.5mA load for only 2 seconds.

You need a motor from a watch, the vibration motor from a cell phone or the tail motor of a small toy helicopter to use such a tiny low power battery cell.

 

[zahrah chaumun]

Helo every1
i need help concerning the programming of encoded dc geared motor using arduino

i am enable to do so whenever i start reading online..
i am not used to code encoded motor and also arduino is new to me
can some1 please help

 

[Audioguru]

Years ago I bought two IR remote controlled cars for $10.00 each. Their tiny motors had a gearbox. They drove fast for their small size.
A guy at the park had a pretty big radio controlled model car that went very fast. I don't know if it had a gearbox.

 

[chuckey]

Audioguru, the "standard " battery for radio controlled cars (say 10 " long) is a 7.2V 5AH nicad, they last up to ten minutes going flat out!! not a CR2032!!
Frank

 

[Audioguru]

Audioguru, the "standard " battery for radio controlled cars (say 10 " long) is a 7.2V 5AH nicad, they last up to ten minutes going flat out!! not a CR2032!!

A CR2032 is a little 3V Lithium coin cell that is not rechargeable.
Here is a modern Li-Po 7.4V 5Ah rechargeable battery that is small, lightweight and can produce 700A (!) in bursts or 350A continuously and is used in RC airplanes, helicopters, cars and boats.