Hi Darren.
We have capability on both welding aluminum and CNC machining. So if you have drawings of the wanted mod than I can review them. I hope you have a large sprag in mind that can hold the torque. For the attachement of the sprag center I think wire edm is the best option. If the center is thick enough the wire edm can be done in the center . If not than a bush with splines inside and a keyway outside can be made by edm.
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