Thank you so much for the reply Mr. coleman…
By servo being stopped, i meant it is stopped by some amount of resistance (in my application) while moving. and it is not able to move against a force. Running torque is almost one-third of the stall torque. Also, my lever arm is of 6 cm. so, all the torque is getting divided by 6. of-course, by decreasing the speed I am able to get full torque. But, I want a certain speed (6 seconds- 120 degree) with more running torque. I am using arduino uno and 6v, 4.5 AH power supply. the system doesn’t have friction because of bearing.
@neha singh We have found the same thing - the “running torque” is less than that of the static torque. The exact fraction is often servo to servo, and the value is never provided by the manufacturer; they only list the maximum stall / static torque. We can only propose that you select a servo which can provide significantly higher static torque than you need and hopefully it can provide enough “dynamic” torque for your application.
Thank you soooo much 
Can you please suggest me the way of controling a biped walking using arduino and gyroscope. So far i get to know is that i’ll have continously measure the center of gravity. I’ve never worked with gyro. And i dnt know how to calculate it
@ahasan That’s a bit beyond the scope of this tutorial; feel free to contact us via the RobotShop Forum and describe what you want to do and what parts you have or are considering.
I’m wondering if there is any Ardino board available , which has both the accelerometer and the microcontroller on the same board?
@vm Yes, there are several such boards. If you want an “all in one”, you might consider the MWC MultiWii Flight Controller or Quadrino Nano Flight Controller, both available from RobotShop.com
hi nice tutorial. I have one question tho, if i wish to find the acceleration of a moving car, what kind of accelerometer should i be using? thanks in advance.
@asf The choice of accelerometer largely depends on the maximum acceleration you think the car will be subjected to, and also the communication method you prefer (serial, I2C, analog etc). Accelerometers also come in one, two or three axes.
i want to join your forume
Hello sir, i am trying to control a bldc motor( with hall sensor and 3 phase) with help of Arduino uno and gyroscope(MPU6050) means i want to make the motor run in frwrd direction when gyroscope is tilted in one direction, and make the motor run in opposite direction when gyroscope is tilted in backward direction, can it be done?? if so how?? please help, motor is 24volt brushless dc motor.
Thank you
First of all, thank you so much for replying to my comments 
Yes Sir, what we are making is kind of similar to two wheel balancing robot, only difference is that, in two wheel balancing robot we use to control two dc motors with single arduino and single gyroscope,BUT in this project we wish to control only a single motor, with single gyroscope and arduino, but the problem is that our motor is not a normal DC motor, it is 3 phase brushless dc motor. What we can’t figure out is that how to control this motor, means we can control it in similar way as we control motors of a quadcopter, but motors of a quadcopter run only in one direction, we don’t know how to change the direction of the 3 phase brushless motor, when gyrsoscope is tilted in opposite direction.
thank you sir
You need an ESC which can rotate the motor in two (rather than just one) direction. Gyro -> Microcontroller -> ESC -> BLDC motor
Hmm…thank you so much sir, we would try our best.
I can not get the accelerometer (arduino lily pad) to change numbers when I run the program
@Sherri P.: Please make a new forum post here for technical help. Make sure to include as many details as possible (setup, code attachments, pictures, etc.) to help determine the issue.
Sir , we have been making a body wear device which should monitor the change in position of body movement . so which sensors should we use and how to monitor 3D maping of body positions.
@Ketan Since this will likely require quite a bit of back and forth communication, we suggest creating a new topic on the RobotShop Forum here: https://www.robotshop.com/forum/
Try to provide as many details as possible (indoor vs outdoor, what you want to track and why etc).