This was inspired by "Paper Clip to set up simple photo background" http://www.thingiverse.com/thing:95180 The curves of slepcat's design are a great idea, but I wanted to use heavier paper than the slots accommodated, and I wished the paper wouldn't come out of the slots so easily. I also wanted a sweep that could stand on its own with more stability.
Although not as elegant as the original, the stand in this design holds thin paper well and also allows for thicker sheets. The rear post helps support a higher background, and there is a plate behind the sweep that can be weighted for added stability.
Please see Instructions for assembly notes.
The file "Paper-Sweep-complete.stl" contains all the parts needed, laid out on a 175mm x 175mm bed, For printers with smaller beds, download the separate parts, printing the pin twice.
The platens attach to the stands as shown using the the pins which go through the holes in the stands and are forced or glued into the receiving holes of the platens. Although most people find this works, there have been a few who've had the pins print out too small; if so, use 3/16" or M5 bolts & nuts.
To use, open the platen and feed the paper between the pivot and the stand. Holding the paper against the stand, close the platen and secure it under the hook on the stand.
The flat plates behind the curves are for weights which are needed for heavier paper. If you plan to use only one size of paper, clamping or gluing the stands to a stiff cardboard or foam-core board will make the setup easier and even more stable.