I’m looking at a few options for a pan and tilt bracket for servo motors. Everything I see has a mount directly on the shaft of the panning servo. I’m wondering how much stress that will create on the motor.
For example, if building a robot claw, and the claw is mounted directly on the shaft of the panning motor, won’t this damage the motor as the weight of the claw and its payload is pulling down on the shaft? I’m thinking that a better solution would involve 2 gears but the fact that everyone is doing it the way that I think is wrong might mean that it is not wrong :).
I can’t find any numbers is the datasheet that mentions the maximum force that can be applied perpendicular and parallel to the shaft. Maybe because it’s irrelevant?
Indeed, if the load is heavy and directly on the servo’s output shaft, the servo can be damaged. You might be thinking about something like this:
This not only provides increased torque because of the gear ratio, but also a very strong bearing supported shaft.
The weight a shaft can support (axially and radially) really depends on the specific servo. If you tell us more about the application, perhaps we can provide additional insights.
Thank you for your reply.
I’m building a robot ARM that has a rotating base powered by a 20kg servo. This rotating base is not sitting on the shaft directly, I’m using a “lazy suzan”.
Then the “boom” part of the arm (in backhoe terminology) is a 150kg servo because I expect this part to require the most strenght.
The “arm” part (second joint) is a 40kg servo. Then at the end is a claw using a 40kg servo too.
My minimum requirement is to lift a tall can of beer with this but if I can go heavier then it’s even better.
Now I’m thinking about adding a rotation for the claw too. This is where I was thinking about connecting it directly to the shaft of another 20kg servo. The servo that you linked would work great but at 280$ it would be over my budget.
I could try to find a smaller rotating plate like a “lazy suzan” but it would need to be smaller (3cm). I could also build a similar device like the one you linked with 2 plastic gears and a servo and a bolt. I just don’t know if I’m over-engineering this knowing that all I wanna do is lift a tall can of beer. But since I have good servos on this device, and I could probably go heavier than a can of beer, I also don’t want the bottleneck to be this rotating part.
