400 gallon project

[Joe Reefer]

HAHA.....she must have been drunk to crawl in the tank with a dress on.

[RicePaddy]

Love the picture. You should have had your wife dress up in a mermaid costume. Or is that your little secret??

Will

[untamed]

Man, I would love it if someone could provide me with a simpler design to do this... If you think you have it, please keep the following in mind:

1) Move the lower frame straight up the upper frame. Lift must be balanced.
2) There's no available room ABOVE the upper frame. Nothing can pass through the lower frame during the lift.

Here is the draft of what I'm thinking of building to hold the lights. What you don't see in this picture is the linear actuator that pulls on the cables. It will sit horizontally in top/middle of the upper frame.

Lights will be mounted under the lower frame.

The whole idea is to lift the lower frame straight up as much as possible..hopefully right up against the upper frame. (about 30")

It's impossible to follow the individual cables in too much detail on this crudely drawn diagram..suffice to say that as the actuator pulls horizontally, the pulleys translate that into vertical pull on all four sides for a straight lift. I think it will work, but....is it ever complicated!



Anyone know a good supplier of pulleys? How about a favourite aluminum fabricator?

[niloc16]

i would try princess auto for the pulleys. they are dirt cheap and have everything. a good friend of mine is a fabricator and a darn good one. have yet to see anything he cannot build or fix. if you want i can talk to him and see what he will charge to build the frame work. do you have the aluminum already? he live in richmond near the airport.

instead of having 4 points of lift, what if you were to put 2 supports across the middle, spaced out, on the lower frame at equal points. this is really hard to explain without drawing but on each of the 2 supports, had 2 attach points that a 1 cable is attached to. so in other words you would end up with a loop of cable attached at both on ends on one support. you would then only have to have 2 cables come down from the upper frame, attach to these 2 looped cable points and lift straight up. you can always use weights at corners to balance the unit if need be. sorry if this is confusing, i wish i could draw it for you

[untamed]

Like this?



I think the problem is that the tighter you make the loops (left), the less stability you get. The larger you make the loops (right), the less you can lift the frame because the peak of the loops will hit the pulleys.

[niloc16]

thats true. the is the idea i was thinking of. ok well back to your first drawing why not lift at the corners rather then the middled of the beams. i think that would give the most stability and even lifting

[untamed]

I think that lifting on the corners offers the most stability because it maximizes the distance between the pull points. Unfortunately, getting the cables to the corners would add even more complexity to the design than I've already got (more pulleys!).

Princess Auto was a great suggestion. I've now got the pulleys that I need.