Motor Mounting

I have a motor that I would like to mount the axle too.

Does any one have any ideas on how to do so?

cog set, pulley+belt, hotglue, shaft coupler, depends , what are you trying to do?

I am trying to build model robotic legs. This is the top of the lower leg.

that still doesn’t tell me what sort of mechanical connecton u are trying to make to the motor…? maybe this will help tho.

I have another aluminium arm like the one in the image which I want to connect.