How to "size" a servo motor?

I have a 28lb solar panel that I'd like to position with servo motors, but not having worked with Servos I'm having a tough time trying to understand how to size the servos that I'll need.

I'm finding a ton of "hobby"/"toy" servos that are rated at 25/30KG but am I under/over-thinking that would equate to the ability of those servos handle the full weight, if centrally positioned, of a 28lb array?

I get that if they weren't centrally positioned I'd need to figure in leverage weight multiplication, etc., but if they were positioned in the center of the array to form 2 axises would a 30KG servo be able to handle the weight of the array?

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iceng22 days ago

Look into gear motors on Grainger or eBay

You will probably have to make your own cam or some limit switches or a sunlight tracker see my diagram..

iceng iceng22 days ago

Click the pic to see the whole image...

ZacWolf (author)  iceng21 days ago

Thanks, yup I'm good there; lots of tracker circuits available, just having a tough time finding the right servos.

Thanks for the help.

iceng ZacWolf21 days ago

BTW even AC gear motors can be reversible and are available in different speeds and there are low voltage DC versions..

Some even have brakes that come on when unpowered..

The next more accurate are Power stepper motors..

You might also look into telescope drive tracking systems..

iceng iceng22 days ago

Do you worry about Wind Loading..

ZacWolf (author)  iceng21 days ago

No, that can be handled separately from the servos.

If you mount the panels equatorially, you can move them with a single linear actuator for a satellite dish. They have all the power you need.

ZacWolf (author)  steveastrouk21 days ago
I have size constraints that don't allow the use of linear actuators for the two axis positioning.

P.S. wasn't the question...

Here's me thinking you were open minded enough to consider a single positioning axis. Sorry

rickharris22 days ago

It may depend on how well balanced the solar panel is. If well adjusted it may take little effort to move it. IF you'r trying to lift the whole panel as a dead weight you going to need more than a hobby servo.

Without seeing detailed plans (IE measurements) of how you intend to connect things up it isn't possible to make definitive statements.

ZacWolf (author)  rickharris22 days ago
Any recommendations for sources of non-hobby actuators? Doing a google search brings back pages and pages of hobby actuators, even when using "Heavy Duty" in the search. Familiar with any brands/vendors for heavier duty actuators?


search (google, bing, etc) on "industrial servo"

ZacWolf (author)  seandogue21 days ago

Excellent! That was the majic wording! Thanks!