OT-Need some Geometry help!
This is a pool deck with an automatic cover under it. The fixed plate is the pool deck, the sliding plate is a tray full of pavers that covers the automatic pool cover and needs to be rolled back for servicing. It weighs at least 1500lbs
I had someone set this all up and used it for a couple of years but only had to actually use it three or 4 times to service the cover underneath. The posts that are on the corners were 4x4 and one cracked so I reinstalled them all with 6x6. Now I can't remember what the 3rd post (in red) was used for.
The point is to be able to use one Come Along to pull both cables evenly instead of using 2 Come Alongs and running back and forth between them to try and keep the pressure even on both cables at the tray is pulled out or back. Like I said I used it several times flwalessly. The idea is that there are anchors at each corner of the sliding cover. The come along is used to pull both cables equally so the cover slides back evenly. To pull the sliding plate/tray back up the cable then runs through a pulley that is mounted ahead of the corner attachment point which reverses the direction of movement of the cable. I think the diagrams capture it. If not I can also add some actual pictures later.
I recall something being attached to that red post to created some kind of fixed point so that the cables moved equally. I can't remember if it was only used when pulling the tray back into place or for both directions. It's there for a reason, I just can't remember or figure it out. I think this is basic geometry and leverage stuff and I am just not smart enough to get my head around it....
Any engineers out there? Below are the diagrams. And below that are some live pictures.
This is the pool cover tray I am trying to move.
In this photo you can see the three posts
This is a shot of one of the posts with the pulley on it to make the 90* turn
This is a close up of how the cables attach to the pool tray.
Thanks!
In this diagram there is an error. The pulley up by the tray is supposed to be attached to the fixed plate/pool deck so there is an anchor point to pull the tray back. It is correct in the photo.
This is a pool deck with an automatic cover under it. The fixed plate is the pool deck, the sliding plate is a tray full of pavers that covers the automatic pool cover and needs to be rolled back for servicing. It weighs at least 1500lbs
I had someone set this all up and used it for a couple of years but only had to actually use it three or 4 times to service the cover underneath. The posts that are on the corners were 4x4 and one cracked so I reinstalled them all with 6x6. Now I can't remember what the 3rd post (in red) was used for.
The point is to be able to use one Come Along to pull both cables evenly instead of using 2 Come Alongs and running back and forth between them to try and keep the pressure even on both cables at the tray is pulled out or back. Like I said I used it several times flwalessly. The idea is that there are anchors at each corner of the sliding cover. The come along is used to pull both cables equally so the cover slides back evenly. To pull the sliding plate/tray back up the cable then runs through a pulley that is mounted ahead of the corner attachment point which reverses the direction of movement of the cable. I think the diagrams capture it. If not I can also add some actual pictures later.
I recall something being attached to that red post to created some kind of fixed point so that the cables moved equally. I can't remember if it was only used when pulling the tray back into place or for both directions. It's there for a reason, I just can't remember or figure it out. I think this is basic geometry and leverage stuff and I am just not smart enough to get my head around it....
Any engineers out there? Below are the diagrams. And below that are some live pictures.
This is the pool cover tray I am trying to move.
In this photo you can see the three posts
This is a shot of one of the posts with the pulley on it to make the 90* turn
This is a close up of how the cables attach to the pool tray.
Thanks!
In this diagram there is an error. The pulley up by the tray is supposed to be attached to the fixed plate/pool deck so there is an anchor point to pull the tray back. It is correct in the photo.
This is a pool deck with an automatic cover under it. The fixed plate is the pool deck, the sliding plate is a tray full of pavers that covers the automatic pool cover and needs to be rolled back for servicing. It weighs at least 1500lbs
I had someone set this all up and used it for a couple of years but only had to actually use it three or 4 times to service the cover underneath. The posts that are on the corners were 4x4 and one cracked so I reinstalled them all with 6x6. Now I can't remember what the 3rd post (in red) was used for.
The point is to be able to use one Come Along to pull both cables evenly instead of using 2 Come Alongs and running back and forth between them to try and keep the pressure even on both cables at the tray is pulled out or back. Like I said I used it several times flwalessly. The idea is that there are anchors at each corner of the sliding cover. The come along is used to pull both cables equally so the cover slides back evenly. To pull the sliding plate/tray back up the cable then runs through a pulley that is mounted ahead of the corner attachment point which reverses the direction of movement of the cable. I think the diagrams capture it. If not I can also add some actual pictures later.
I recall something being attached to that red post to created some kind of fixed point so that the cables moved equally. I can't remember if it was only used when pulling the tray back into place or for both directions. It's there for a reason, I just can't remember or figure it out. I think this is basic geometry and leverage stuff and I am just not smart enough to get my head around it....
Any engineers out there? Below are the diagrams. And below that are some live pictures.
This is the pool cover tray I am trying to move.
In this photo you can see the three posts
This is a shot of one of the posts with the pulley on it to make the 90* turn
This is a close up of how the cables attach to the pool tray.
Thanks!
In this diagram there is an error. The pulley up by the tray is supposed to be attached to the fixed plate/pool deck so there is an anchor point to pull the tray back. It is correct in the photo.
A come along connecting both lines should pull equally if the line tensions are equal enough. My question is does the come along have enough coil capacity to take up both lines to complete the move distance?







