I have a setup in which a bolt threaded on two ends with an unthreaded shank in the middle will be rotated by the unthreaded shank area. That is, the bolt's axis of rotation is roughly the red cross:
I wonder if there's a small part/connector that I could fit over the unthreaded shank so that a shaft could be connected to the connector such that the bolt can be rotated. Perhaps, something like below where the top is a hex/square hole and the bottom is a threaded hole?
Alternatively, are there low-profile setups where a bolt can be rotated around the centre?