I made this spool holder so it won't allow a nearly empty spool to flip out of the roller style holders. It does use 3 ¼ inch bolts and I need to create a couple of more spacers. I designed the side and the bottom spacers before I actually did the top roller and the clip style brackets to hold the roller in place at the top of the sides (spool risers) of the folder. So, the bottom spacers are about ½ inch too short. But my plan is to make a spacer that will rest on the source as the bottom if the risers do and probably glue the spacer to the riser which should had some better stability to the riser.
The author marked this model as their own original creation.