Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4646929.
There are a lot of servo fittings on the splines for 9kg servos. But there is a lack of 11kg servo fittings so here is the basic arm and just the round piece to remix.
Be aware to use it for a servo LIKE the MG995 or MG996. Because they have higher torque the spline is bigger.