Connect a continuous rotation modified servo to MicroMaestro

O.K. So I just got the USB Micro Maestro 6 channel servo controller in the mail today!

I’m very excited! This little device makes my eyes and imagination sparkle with delight.

I’ve already connected a batter pack (4-AA) to the servo bus and have two Futaba S3004 servos hooked up and it’s working beautifully! Haven’t done any scripting yet, but the little control center gui is pretty easy to play with. :slight_smile:

So here’s my plan: I need to remotely control 2 servos attached to a webcam over the internet. I’d like to have a continuous servo for the x-axis and just about any servo will do for the y-axis of the movement.

I’ll be using Skype which can easily be configured to automatically pick up the call when I place it.

Here’s my problem. I want a continuous rotation servo for the x-axis, and from a previous project (the incredibly useless machine) I have a modded Futaba S3003 which allows continuous rotation however it lacks a signal wire. The mod simply had me remove the leads from the H-bridge, remove the H-bridge, solder the black and red wires directly to the motor, and remove the plastic nub from the gear which prevents 360 degree rotation.

In the end, the modded servo has become a 4.8 to 6 volt motor connected to a gear box.

I would like to connect this motor to the servo bus and use it to spin the camera back and forth. I still have the H-bridge, which I learned recently allows the unit to reverse the power feed. Would I simply reconnect the H-bridge and remove the potentiometer to allow the Maestro to turn the servo continuously or what?

Also, I know that commercial servos are available that have continuous rotation, but since I have a lot of the materials already I’m trying to get away without ordering yet another part.



Do you understand that you lose position control when you change a servo to continuous rotation? It seems like using a continuous servo would be asking for your cables getting tangled up. If you need 360-degree range, you can get a single turn servo that will give you a bit over 360 degrees of range while still maintaining position control.

If you want to restore your gearmotor to a servo, then yes, you would have to restore its electronics. There’s much more than just an H-bridge there. There are lots of web pages about modifying servos for continuous rotation, so you can look there for more information, but basically, you have to enable continuous mechanical rotation, which you have already done, and disconnect the output shaft from the potentiometer without taking the potentiometer out of the electrical circuit (and set the pot to the middle of its range).

- Jan

Thank you. “^_^”

I discovered that method about an hour after I posted simply by playing around with my servos.

Yah, I know I’ll lose position control, but that won’t be necessary if I have two bump sensors on the left and right of my webcam. They’ll be configured to disallow movement in a specific direction if they’re pressed.

Actually… I’ve been able to configure one of my 60 deg. servos to go a bit over 180 deg. (which is what I required in the first place. So I’m not sure I’ll even go with the continuous servo method anymore.

Prototyping is a very indecisive mistress…