# Rotating a lever with a small servo

I'm trying to rotate a lever link to gently "offload" a load using a servo. Here's a drawing:

Here, the red is a lever, yellow pivot and black is the load. To offload, the lever needs to be turned 90 degrees. I know I could simply put a servo where the yellow pivot is, but the problem is that the servo may not have enough torque to hold the load. The load is typically around 1-2kg and the distance from the pivot is around 15cm. The servo has a stall torque of around 10kg-cm.

Is it a good idea to drive a cable on the right hand side of the lever with a servo? Or is there a link setup that allows such a small servo to drive this lever?

• is there any way that you could counterbalance the load? Jan 22, 2020 at 7:04
• @jsotola You mean counter balance the load and have the servo at the pivot? I'm trying to minimise the weight in the lever if I can. Jan 22, 2020 at 7:38

From your numbers, I believe you need something that can support at least ~30kg-cm torque at the load, unless you make other changes. A few options: