Some motor questions

Yup

Get someone in to do it for you.

Have you considered the electrical issue near the pool? Having 2 motors sounds like a dangerous/ complicated situation to me. I will not even swim in my pool when the light is on. Nor will I allow anyone in the water. My home my rules. Look into something like a garage door opener. Fair amount of torque and the stops are already prewired. You will have to attach cables or chain from one spool to the other so you get the pull and push that your looking for. Having 2 motors sounds more like a synchronization issue to me. One motor driving both spools sounds easier. The there is the matter of the track down each side. To keep the cover down and doing its job. might be easier to build a solid cover and use a screw or scissor mechanism to open and close it. Something like what they use for the retractable stadiums ceilings. It could run on a rail down both sides and stack up like seats in a gym.

Eliminate the cable spool. Run the cables through pulleys and back to the canopy spool. Wind the cables around the ends of the canopy spool in such a direction that winding the canopy unwinds the cables and vice versa. At the pulley ends, mount the pulleys on sliding tracks held by springs that can be adjusted to maintain the proper system tension.

Use worm drive gear reduction units. However, with the above cable pulley system, you won't need to 'lock' the spool since the torque imposed on it by the tensioned canopy will be opposed by the torque imposed by the tensioned cables.

C, D and E depend on how fast you want to deploy the canopy.

The structural (and related safety and liability) issues surrounding this might warrant having the design done or reviewed by a licensed P.E.

This is a rather complex setup you are purposing. I believe ultimately you would be much happier if you hired the services of an engineer, or a technician experienced in these type of designs. At the least have a system designed for your needs, and secure at least occasional limited supervision while you install it.

That said there is a motor/system designed for greenhouse use that sounds as if it would fit your needs precisely! There is a cylinder shaped motor/gear reduction assembly (available in single, or three phase) that is designed to fit inside a take-up spool, or mount on the end, that has adjustable up/down limit switches. The use I observed it applied to was covering/uncovering the glass ceiling of a greenhouse. It was rather slow to operate, but very effective, and predictable. After installation there was a bit of time required to set the upper/lower limits, but after that it operated flawlessly. I believe the company making the system was from Germany. Check with various greenhouse suppliers to find a vendor where you live.

Louis

get some gfi sockets and you are safe

GFI's are good - but there's a whole bunch of safety requirements pertaining to electrical wiring around the pool that they don't address.

Fortunately, no motors or wiring will be near the pool itself. The motor would be mounted on a second floor balcony, which already has an adjacent outdoor (GFI) socket.

Thanks

Like what, pray tell?

Grounding, bonding, overhead wiring clearances, wiring methods, locations of receptacles, etc. It is all there in NEC article 680. Of particular relevance to this thread is 680.27.B "Electrically operated pool covers" which discusses location and protection of the motors.

Ben Miller