Can a mechanical engineer (or other smart person) solve this fence design problem?
I need to create a net system to keep basketballs from flying over the neighbors fence & crushing their flowers, etc. I currently have a sport court-type volleyball/tennis net system installed which is perpendicular to the wooden fence shared with the neighbors. (See images) The support pole appears to be steel (probably galvanized) and is coated with a black material, which I assume helps it to be more weather resistant. It is a hollow pole 3"x3". The bolts attached to the pole on the side opposite the fence to attach the tennis/volleyball net at various heights protrude about 1/4"-1/2" into the pole's interior. The pole has a hollow base (18" deep) which is installed into the ground with a 1/4" lip & the pole is able to be removed. The wooden fence is 5.5' tall. The top of the pole is 3' higher than the fence when installed, and is therefore about 10' total.
I would like a net system which runs along the fence (perpendicular to the installed volleyball/tennis system) and raises 7-8' higher than the wooden fence, but which can be lowered when not in use so that the top of the net is flush with the wooden fence and the pole remains at its current height. (See images) Keeping the net raised at all times would be very ugly, and I am certain the neighbors would have us take it down. I have thought of many different ideas, but can't seem to determine which would be the best method to accomplish this.
I believe I'll need to dig holes at either side of the fence to install two more removable 10' poles, making the existing pole the middle point. Each pole would be 31' from the existing center pole, making the distance from one exterior pole to the other 62'. Have 2 separate nets, one for each side, each about 30' in length and about 8-9' tall. The nets would attach to the poles, and would collapse along the fence when not in use. I don't want the nets to go all the way to the ground when not in use, however. I want them to simply bunch near the top of the fence when lowered.
This is where I'm stumped. A few ideas are as follows:
1- Install poles on the interior of the existing (and 2 new) poles which slide up and down. The problem with this are the screws which are on the inside of the pole. Also, if I were to attach bolt connections for the attachment of nets, how would I do that and still have the pole fit inside the existing pole as it slid up and down? What mechanism would I use to lower and raise the poles? A pulley system design with a crank? A motorized winch?
2- Install poles on the exterior of the existing poles. As one side already has screws to attach the volleyball/tennis net, I don't know how this would fit over the existing pole. Again, running into a problem when bolts need to be screwed into the poles to attach the retaining net connectors. Again, what mechanism would I use to lower and raise the poles? A pulley system design with a crank? A motorized winch?
3- Install lighter extension poles which fold down at a 90 degree angle, with net already attached and lock in place when fully raised. I'm not sure how sturdy this would be when the poles were raised to their full height. I'm also not sure how the pole would be raised and lowered from it's down position. Would the angle work well if it had some sort of metal cable winch system?
Those are the ideas I have as of now. I'd prefer a system which can be raised and lowered by 1 person alone with minimal effort, but don't know if that's possible. I'd also prefer the cheapest method possible, but would be willing to spend a little more on an electrical (winch or other) system if it made the task of lowering and raising much easier AND SAFER than a manual hand crank, especially if it could be done by one person alone.
I'm imagining there is a way, and I'm pretty good at things like this'but this one has me stumped so I'm hoping someone out there has some great ideas for me! You can view images by clicking this link, then enlarge each image by clicking on it. Thanks!
