I bought a frame adaptor for my Lowery embroidery stand so that I could more easily use a roller frame and embroider larger projects without having to remove and re-position the fabric as much I might otherwise have to do if I used a hoop, and the frame can also easily be moved from side to side without much effort.
I recently put the Victorian Street WIP that I started in 1983 or thereabouts onto a large Elbesee Easy Clip Roller Frame but in order for the adaptor’s plates not to dig into the front of the fabric, I turned them to face outwards as you can see in image two. The first image shows the metal plates in the default position, i.e. curving in towards each other. Yes, of course I could have removed the fabric from the roller frame and remounted it as per the Elbesee instructions (i.e. with the back of the work visible on the roller bars) but I haven’t had any loss of tension on the fabric and the frame is still held securely this way so this is how it will remain. The third image shows how the adaptor is attached to the Lowery stand clamp.