Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: Greenfield on July 04, 2008, 10:21:47 AM

Title: servo gap
Post by: Greenfield on July 04, 2008, 10:21:47 AM

I read the robot arm tutorial and have a question.
What servos can be used in each degree of freedom?
For example gear servos has a gap.
First joint has gap about 0.1 mm on 20 mm gear radius
so in degrees it be about 0.28 degree
If first arm length is 100 mm, then gap where second
joint starts will be about 0.5 mm
So on DOF 4 it can be about 10 mm or more, it very big inaccuracy.

Title: Re: servo gap
Post by: Admin on July 13, 2008, 09:58:04 AM

Yeap, this is a problem inherent in all gears. In fact, a problem inherent in all robot arms . . .

You need to determine first what your acceptable error is (its impossible to have 0 error in any system). Then you need to incorporate sensors to correct for that error, like encoders or a camera for example.