Motorized light rack to simulate travel of the sun

[fjr_wertheimber]

Okay, I've searched all over the site (and others as well) and can't seem to find quite what I'm looking for... When I do a search on "motorized light rack", I find a bunch of mentions of light racks that lift up and out of the way so you can work on your tank, but that's not what I want.

What do I want, you ask?

I want a motorized system of some sort (from the research I've done, probably utilitizing a stepping motor) that over the course of 24 hours will move a light rack 12" in one lateral direction and back again.

The idea is to light a 72"x36"x27" 300g tank with AquaIllumination LED lights, taking advantage of their narrow lighting to make some interesting lighting effects. You see, I want to build up a staggered set of 6 live rock and coral columns, with an AI unit over each on a custom-built sliding light rack. At the start of each day, as the Profilux controller starts ramping up the lights, the LEDs start off 6" to one side of the rock pillar (let's call it the east side) then when they're at their brightest at midday, they're directly over the rock pillar (much as the sun is at its brightest when directly overhead) and then continues to travel a further 6" to the "west" side of the tank until the LEDs dim and transition to "moonlight" at which point they reverse their course and over the course of the next 12 hours return to their starting points.

Thoughts, ideas? Anyone know of a good/simple/relatively-inexpensive way to do this?

[NanoReefWanabe]

there has been tonnes of talk on here about systems like this...most are done with threaded rod a couple nuts and a small high torque low RPM motor...most i think are DC and are easily reversible...

[Bamm Bamm]

they sell them at your local Hydropnics store also

[Ding2daDong]

I know this is a DIY forum but I know sunlightsupply makes a light mover. I think reef geek carries it.

hth

-Matthew

[BenjieC]

The commercial light movers won't move that slow unless you have them on a timer, which kills the motors.

[Bamm Bamm]

Sunlight supply=hydrponics but now reefersare buying the stuff for tanks

[jbird69]

My LFS has a 5' cube that is lit with one 1000w mh (plus a bunch of leds) Hes rigged a light mover that is circular. It takes about 30 minutes ( I think...maybe longer) to make a full revolution. Very neat, efficient set up.

[njsurfcaster]

I would look at theatrical and concert stage lighting for ideas that you may be able to incorporate.

[SWINGRRRR]

Searched?? (http://www.reefcentral.com/forums/showthread.php?t=1601895&highlight=light+rail)

[khanb31]

I want a motorized system of some sort (from the research I've done, probably utilitizing a stepping motor) that over the course of 24 hours will move a light rack 12" in one lateral direction and back again.



Well, I have actually incorporated this scheme into my current tank. The only difficult part that your going to run into is making this work for only 12 inches. They make different length light racks but not that short. I personally have the 48" model over my tank. It is driven by a chain and goes back and forth across the length of the tank throughout the course of the day. The best way to have this thing move across the distance over 12 hours is to just have it turn on for a certain # of seconds per hour. You can set that on any reefkeeper. I have mine set to turn on for 4 mins every hour. This allows it to come close to tank length over the course of 12 hours.

Im actually selling my current one because im switching from MH to T5's. The heat is just too much for me. send me a PM if your interested or have any questions on my setup. I can take pictures for you.

[thetonyage]

That Fish Place in lancaster has a setup like that for their corals, seems pretty sweet

[fjr_wertheimber]

Okay, so I think I've actually got it figured out, without having to use a chain- or track-driven light mover, both of which systems are too fast and made for much larger movements than I need...

I'm going to use two 6" linear actuators, cascaded, run by X10 switches (controlled by an X10 automation system or ACIII... anyone know if the Profilux 3 can control X10?). So at midday in the light cycle, the X10 tells one switch "on", that linear actuator extends 6" (and pushes the light rack 6" from the fully "east" position to the "directly overhead noon" position), then towards late afternoon in the light cycle, the second linear actuator is turned on by X10 (and into the fully "west" position). At "midnight" in the light cycle, the second linear actuator is turned off by X10 (collapsing it) and then a few hours later the first linear actuator is turned off, collapsing the whole thing back into it's original location.

Thoughts/comments? I think this should work out pretty well, what do y'all think?