Backdrop roll mandrel

This was created so I could have my photography backdrops rolled up and I could quickly change them out. It is created to be used with 1.25" PVC conduit and an 8" long 3/8" bolt and 3/8" nut. I provide the scad files so one should be able to tweak it for whatever bolt you want to use, yes even you metric folks ( :) honestly I really don't care as long as it holds things together I had a lot of 3/8"-8" on hand). I did JB weld the nut into the wedge with fins because it helps if you want to remove the mandrel from the conduit.

Note on attaching backdrops: I use a piece of angle aluminum about 1" on the conduit to draw a straight line, then I found that gaffers tape seems to work best to attach the backdrop to the conduit. I add tape to one side making sure everything is aligned then fold it over to attach the other side. I tried only one-sided taped, but after a while, it would come undone. I also tried duct tape but that seemed to be too thick. 

And yes if your mind goes to a dirty place I know what it might look like, it is just form and function.