Just started using Arduino yesterday. Very cool. I'm updating my flight simulator with servo driven gauges. I need a range of about 360 degrees but not continuous rotation. A mini or micro servo would be best. It will only be turning a gauge pointer so it doesn't have to be strong. Can anyone offer a suggestion?
Thanks,
John
The kind of servo you are looking for is typically called a "winch" servo - typically used on R/C sail boats. They tend to have large torque, too - in fact, they would be overkill for this project (they tend to be multiple rotation, but not continuous rotation).
Instead, what you might do is gear up the output; a slightly larger gear on the output of the servo, and a smaller gear (a belt or string drive could also work) on the gauge would give you greater angular resolving, at a slight loss of resolution.
Thank you gentlemen. I was considering doing a 2:1 gear pair but am concerned I may realize a loss of resolution and that any jittering of the servo motion would be compounded.
Zoomcat, Do you have any experience with the servo you recommended? I've read that some of the winch servos lack precision.
Also, I plan on running 16 servos on 1 MEGA2560 board. can/should I power them remotely to minimize the risk of burning out my board?
Thanks,
John
Thick8:
Thank you gentlemen. I was considering doing a 2:1 gear pair but am concerned I may realize a loss of resolution and that any jittering of the servo motion would be compounded.
Zoomcat, Do you have any experience with the servo you recommended? I've read that some of the winch servos lack precision.
Also, I plan on running 16 servos on 1 MEGA2560 board. can/should I power them remotely to minimize the risk of burning out my board?
Thanks,
John
If you prepare two batteries, one for your board and the other for your servos, I think it will be ok.
I assume sail winch servos use the same pot that normal servos use, and the rotation range difference is in the gearing. The servo I referenced states it makes somewhere between 1.5 to 1.75 turns full rotation. I've tested a standard servo and in its 190 deg of rotation I saw ~425 discrete positions available. If these assumptions are valid, you should be able to roughly calculate the resolution of the sail winch servo. If you are good at working with small things, you might be able to make a simple gear up arrangement for the gauge needle using simple components.
Thank you crOsh and Zoomcat. Your suggestion led me on a search in which I found 359 degree servos. I ordered a few to test. I'll let you know how they work out.
Thanks,
John