Hi All:
FYI - DaveV and I found the round "toit" to re-start a discussion towards making positive baby steps on this project.
The original spec for the fab lab calls for four motorized window shades; two at 60" wide x 80" tall, and two at 60" wide x 40" tall.
Wih appropriate consideration for the many cold-fusion powered concepts proposed in the initial discussion, our current limited vision for the first baby steps starts as follows:
(1) Make four rollers - Use 1" diameter EMT conduit [https://www.homedepot.com/p/1-in-x-10-ft-Electric-Metallic-Tube-EMT-Conduit-101568/100400409] and cut four lengths to be a bit more than the nominal 60" shade width. Deburr and chamfer the roller ends to be square. We would then lathe eight plug/bushings to have an OD press/weld/bond fit into the ID ends of each conduit . Each plug/bushing ID would have a similar press/weld/bond fit for a nominal 1/4"-3/8" or metric steel shaft extension. The right-side drive shaft extension would be a bit longer than the left-side idler shaft extension.
(2) Make eight support brackets - There would be four left idler-side and four right drive-side brackets. The brackets would mount rigidly on the wall or window sills at the top left and right corners of each of the four windows. Each bracket would mount a spherical bearing/bushing (or have an oversized hole) for the roller shaft extensions. Bonus points for bracket design considerations to facilitate insertion, removal, aligning and leveling the 60" long roller to spin supported by the brackets on each end. Band saw cut brackets from 2x4 wood or devise something fancier.
(3) Source and procure the roller shade material - Again, this would be four pieces, two at 60" wide x 80" tall, and two at 60" wide x 40" tall. We are not going for full black-out shades, but rather something that would still let in some light, but block the UV afternoon heat. This site has some interesting options available fro internet sources. https://www.phifer.com/sun-control/residential/
(4) Attach and hang the procured shade material on the rollers - Design the shade attachment to the roller. Use a center-attach "crowned" roller concept with the roller perfectly level to the horizon so that the shade rolls up square on the roll and does not spiral off to jam into either the left or right support during the 80" of roll-up travel (something like 20-25 turns depending upon shade material thickness). Include a bottom shade rail/bar with some weight for smooth and consistent gravity rolling/unrolling spooling action.
(5) Functional Validation - This could be any one of several (even manua)l means to roll-up, and unroll the shades multiple times to confirm 100% motion travel reliability. This functional validation would enable determining the motorization design parameters for speed, torque, and duty-cycle.
(5) Motorization - The fun part.
This was originally proposed as a collaborative project.
The numbered steps are how I will proceed assuming no strong dissent and I do the work myself on my availability schedule. Others are welcome to agree and step in to follow-along with this general approach and help to get it done faster with more collaboration. Others are also welcome to verbalize any of the other million ways to skin this cat, with the expectation they will follow up with positive actions to actually implement their alternate approach and get it done.
JimD
