Marc,
This is a bit indirect, as it is part of a whole kit of adaptors that I use. I use them as vertical extensions, and horizontal extensions, with manfrotto mini clamp, and larger super clamps; bear with....
I carry a series of all-thread rod sections, derived from 3/8-16 stock. I carry a selection of extensions between 6" to 3' long (the sizes that are readily available at the hardware store). I use an thread rod ferrule connector (a 4x long nut), and, wing nuts. The thread rod connector ferrule gives you a deep female thread set, and the wingnut is your jam/lock nut. I cover the all-thread rod in black heat shrink to conceal the threads
It requires that you have a 5/8-27_to_3/8-16 adaptor on your stand (I no longer run the larger thread pitch at all).
I'm looking for some pics; check back.
pics:
This is what I could quickly find; think creatively....
This is a combination of a longer section of thread rod, connected to a kick drum stand, and, on top of it, is a shorter section of thread rod stock to extend the stand for a second set of mics. All of the vertical sections are of this thread rod stock, connector ferrules and wing nuts.
rambling legend of image 6840:
> near the bottom is a red adaptor. that is the 58-27->3/8-16 adaptor.
> 2' thread rod with female ferrule connector and wingnut to attach and secure.
> At J-Disc has a ferrule connector (silver) and wing nuts, and, a thread set to allow for another extension
> 6" thread rod extension with silver ferrule connector and wing nut, with t-bar at top (xy config)
image2979:
Again with the thread rod. This time, bent at 90º, to achieve perpendicular horizontal angle to the vertical stand.
There is also a silver 5/8->3/8-16 adaptor where the thread rod begins at the top of the "base" stand.
The main thread rod vertical element in this image is a 3' section.