Thanks for the kind words....I will try to do a video clip to show it moving next couple of days.

I used the same neoprene coated nylon fabric for the Y axis that I had for the X-axis, only 22mil thick instead of 40 mil. The mechanism is very simple to make, took me only a few hours (plus some design time on the CAD). I used following McMaster parts:
- Fabric (8811K117 22mil and 8811K561 40mil)
- Aluminum tube 0.75"OD and 0.68"ID (89965K62)
- M6 threaded rod as axle(9907A245)
- Also 2 cheap shielded bearings 17mm OD x 6mm ID from VXB for each of the 4 tube shafts fastened with nylock nuts to the axle.

Since the tube is a tiny bit oversized for the bearings, I hammered a small crimp groove around the lower part of the tube (using a spare bearing as mandrel) so that the tube rests on the lower bearing. The fabric is attached to the tube with 2" wide Gorilla Tape and never unwinds completely, so the tape does not have to carry the tension.

I am not sure if roll-up blinds would work well, because you need to have good constant tension (I use about 5 pounds) on the curtain to guarantee it moves even when the curtain has some friction in the guides. Otherwise it would bunch up and may cause some damage. The spring forces of a real blind are probably not sufficient and changing when rolled up. It might be more work to modify than to make one from scratch.