# Need help with Control center to do a 45 degree sweep

Hi Folks,

New to servos. I have the 12 channel Maestro.

I need to create a 45 degree +/- servo horn sweep in Control center.
When i start to move the sliders to try to build frames for a sequence, the servo is going wildly in one direction or starts to spin on a continuing basis.

The servos i got were continuous rotations so that might be my problem altogether but i want to check if i still can get the servo to do a small controlled sweep.

Control center does not give you a visual feedback on angles so it is hard for me to wrap my head around all of this and i need this to work for a robotics project.

I have 180’s only coming my way but i would like to be able to use the other ones if possible. Can someone help me with this or point me to a good in depth tutorial on how to deal with this kind of thing.

Hello.

Continuous rotation servos sacrifice their ability to do position control for the ability to spin continuously. Essentially, the pulse width signal sent from the Maestro controls the speed and direction of the servo instead of the position (typically 1500µs is the neutral or stopped position, higher than that will go in one direction, lower will go in the other, and the speed will be higher as the value gets farther from the neutral position).

So, the best way to attempt a sweep like that with continuous rotation servos without some kind of additional limit switches or feedback would probably be to do it based on timing, which probably won’t be very accurate and could vary based on the load applied to the servo. If you need to sweep between two set positions, you’re probably better off using standard servos instead of continuous rotation servos.

The Maestro does not have access to the servo’s internal feedback information, so it cannot give you any visual feedback about the angle of the servo. To clarify, the Maestro sends a pulse width signal to the servo, and the electronics inside the servo process that signal and drive the servo motor to the commanded position using the internal feedback (typically a potentiometer inside the servo) as reference; it does not relay any of that information back to the Maestro, and every servo will handle it differently. Even servos of the same model might have some variations in position given the same pulse width, so I recommend doing some calibration tests with your particular servos.

Brandon

Appreciated Brandon

It helps me understand the process.