how to change servo motor PWM

[mackrackit]

Not sure how it works...but I'm going to guess...
The servo's feedback pot is mechanically disconnected and locked into the 'center' position? Assume that this servo's center is 1.5ms. You give it a pulse of 1.6ms, it runs right at X speed. You give it a pulse of 1.7ms, it runs right at 2X speed. Same thing for the other direction? You give it a 1.4ms pulse, it runs left at X speed, pulse it at 1.3ms, and it runs left at 2X speed?
Therefore, the farther the input pulse is from 1.5ms, the faster it will travel in that particular direction?

You got it. They used to sell these with instructions to modify, now they do the modification for you.
Makes really nice rolling gizmos.

[skimask]

You got it. They used to sell these with instructions to modify, now they do the modification for you.
Makes really nice rolling gizmos.

So, if you get a servo with a really tight deadband, it could be almost impossible to get the motor to stop 'cause it would always be trying to hit that sweet spot?

[mackrackit]

I have only used a dozen or so of these and have only had that problem a couple of times, but the little screw inside makes them adjustable. So it is not that big of a problem.

[skimask]

I have only used a dozen or so of these and have only had that problem a couple of times, but the little screw inside makes them adjustable. So it is not that big of a problem.

Well, that's a handy bit of information. I didn't know those types of servos were any sort of popular and/or used that much. That'll come in handy for a few things I've been wanting to mess with.

[rmteo]

Modifying R/C servos in the manner you described have been a fairly common way to get a low speed/low torque reversible motive system.