How can I make this robot mech work?

Hello, I am working on a robotic mech that is able to have abilities and be able to move. The abilities work but it doesnt move well… I tried welding and joining all its part to a r15 humanoid and then it didn’t really move smoothly as the character just malfunctions when its walking/moving. Does anyone know another way on how to make this thing be able to move smoothly
AlienMech
?

Use the RigEdit plugin and manually rig the robot mech yourself.

I personally won’t weld anything as custom and different as your robot mech to an R15 humanoid, it would look messy and weird.