Keep things in place on a 3/4" PVC pipe. I use these to keep my spools from wandering all over during a print job. They keep a tight grip on the pipe but flex to accommodate variances in pipe diameter.
Has fun designing, printing, tinkering with 3D printed cameras (creator of Flyer 6x6, Clipper 6x18, funded by "Pinhole Printed" Kickstarter) and open source 35mm film to 120 spool adapter. @pinholeprinted