Gantry Water Ripple Generator

[rhizotron]

Gantry Water Ripple Generator

Here's is a new project I've started a continuation of a few related ideas. The basic idea is a ripple generating paddle held over the tank water with a gantry assembly and powered by a stepper motor v-slot linear actuator.

This is just a preliminary setup. While the extruded aluminum gantry and moving parts seem to run well, with some more work I can improve the paddle + bracket design. I currently have the paddle running with a simple forward & reverse motion, but there are lots of possibilities for stepper motor control for various water ripple effects. The most compelling visual aspect of these projects has been shadow patterns cast on the tank bottom and the reflection patterns on the room ceiling and walls; I also have additional ideas for the lighting setup.

The tank is just filled with water, but I have concept for stocking it and currently rounding up and QTing my live organisms.

I might have an updated paddle design pretty soon and I'll also have video on the way.

 

[wmv]

I might have missed this on your past thread, but if you don't mind sharing whats the cost on building something like this?

 

[rhizotron]

I might have missed this on your past thread, but if you don't mind sharing whats the cost on building something like this?

Most of these parts were scrounged, but the gantry assembly was purchased as a kit for seventy dollars. The microcontroller, motor shield and stepper driver were about twenty-five dollars.

The tank is an old 40 breeder with the top plastic rim popped off. I have wanted to use it for a project for some time and it is a good size and shape for this.

 

[delv2323]

I would like to see a preliminary video please!

 

[blecki]

How well is a 40 breeder going to hold up if the rim is taken off? I imagine the glass is thinner than it would be in a rimless version.

 

[CBonito]

This is the coolest thing I've seen in a while. I guess if it stays far enough over the water there isnt any real concern. PLUS, it wont chew up any anemones or snails.

 

[rhizotron]

I would like to see a preliminary video please!

Yep I'll get some. The ripples create really fascinating patterns with reflections on the ceiling.

I managed to lose my phone and I'm still hoping it might turn up before I get a new one. In the meantime I'm borrowing my wife's for pics and whatever and that's pretty annoying for her of course, LOL.

How well is a 40 breeder going to hold up if the rim is taken off? I imagine the glass is thinner than it would be in a rimless version.

It will be fine. That glass is about 1/4" and indeed a bit thinner than for a rimless tank of comparable size. But for the sake of containing the ripples/waves as well as fish I will keep the water level about 3" below the top rim. I had this same tank set up like for years with plants growing out the top and with no issues.

enough over the water there isnt any real concern. PLUS, it wont chew up any anemones or snails.

Ripples easily travel down the length of this 3-foot tank, but it will be interesting to see how well the energy propagates down into the water vertically. Paddle length may be a factor in this. It will be easier to see when I get live plants in here and can observe their foliage movement.

 

[CBonito]

Ripples easily travel down the length of this 3-foot tank, but it will be interesting to see how well the energy propagates down into the water vertically. Paddle length may be a factor in this. It will be easier to see when I get live plants in here and can observe their foliage movement.

If you had that paddle run back and forth down the length of the tank, I'd be willing to bet there would be a strong movement from the surface all the way down. I have a 3 foot tank that's 12" tall and it would do that for sure in mine.

 

[rhizotron]

If you had that paddle run back and forth down the length of the tank, I'd be willing to bet there would be a strong movement from the surface all the way down. I have a 3 foot tank that's 12" tall and it would do that for sure in mine.

Yeah you can get that aluminum rail in lengths to at least 2000mm. I have a couple other different configurations in mind. Running down the length of the a long tank could really energize the water functioning like this machine, but at much smaller scale.

 

[CBonito]

Yeah you can get that aluminum rail in lengths to at least 2000mm. I have a couple other different configurations in mind. Running down the length of the a long tank could really energize the water functioning like this machine, but at much smaller scale.

Oh I know it will for sure! You can move a lot of water that way because of the quick displacement at the surface. You can get some really killer wave motion, or surge depending on the speed/distance of the "flipper".

It's cool to see someone playing with this.

 

[rhizotron]

Oh I know it will for sure! You can move a lot of water that way because of the quick displacement at the surface. You can get some really killer wave motion, or surge depending on the speed/distance of the "flipper".

It's cool to see someone playing with this.

Noise is one issue. The faster the stepper is running and the heavier the load, the louder the mechanism is. The key I think is to control it with intermittent actuation so that it's not a constant rhythmic back and forth, which will drive you nuts.

For running waves down the length of the tank like traveling water waves, you could either return the paddle to the starti real slow, or lift it free of the water with a servo. This would require an additional cable running to the moving paddle bracket.

 

[rhizotron]

I've made some more progress here.

There is sand in the tank.

The updated paddle design swivels on the rod spindle from the gantry plate. A short peg at the top of the paddle indexes with a part on the spindle to control the degrees of rotation through each paddle stroke. Here I set it up so that the paddle stops perpendicular to the V-slot for the forward stroke, but folds back to feather for the return stroke.

A lot of the stepper motor energy gets expended with vortices around the paddle, rather than with directional water motion in the aquarium. But these mini whirlpools create their own interesting shadow and reflected ripple effects. When in operation there are nice directional mellow ripples down the length of the tank to make a shallow tropical lagoon effect, which is what I have in mind.

I added stepper motor limit switches, but have not yet wired or programmed them with the microcontroller.

I hung a new 55-watt PAR38 over the tank for maintaining some of the biota I'm putting in here. This thing is super bright, like a street lamp, but with LEDs distributed all over the front of the reflector area, it is poor for ripple shadow and reflection effect. For better expression of the water ripples, I can swap this one out in the fixture for one of the other screw-ins I have with a single COB LED as a better point-source light.

 

[CBonito]

It's like a rudder.

 

[Joekovar]

While extremely cool, all those exposed electronics so close to saltwater make me nervous.

 

[Osbie Feel]

This is really cool! I would love to see a video. What do you plan on stocking the tank with?

 

[CBonito]

While extremely cool, all those exposed electronics so close to saltwater make me nervous.

It's an experiment being done by a competent individual to see what he can come up with as an alternate way to make waves. And you have to start somewhere.

Have you ever gone into the garage to see what ways you can get hurt?
I can't even post my garage...you'd laugh.

 

[Joekovar]

It's an experiment being done by a competent individual to see what he can come up with as an alternate way to make waves. And you have to start somewhere.

Have you ever gone into the garage to see what ways you can get hurt?
I can't even post my garage...you'd laugh.

I mean, I can look at the quality of the build and tell they're probably not going to electrocute themselves or burn their house down.

I learned about wire gauge and current by burning my tree fort to the ground, and melting the siding off the neighbors house when I was a kid... I've learned a lot of things the hard way. (Ironically, I work in the fire alarm industry now)

One of those things is that salty air can rapidly destroy electronics. I made the mistake of keeping a reef tank and a rack server in the same room and had to replace parts of the server that corroded.

It's the exposed connections and how fast I've seen things corrode that makes me nervous.

 

[CBonito]

I mean, I can look at the quality of the build and tell they're probably not going to electrocute themselves or burn their house down.

I learned about wire gauge and current by burning my tree fort to the ground, and melting the siding off the neighbors house when I was a kid... I've learned a lot of things the hard way. (Ironically, I work in the fire alarm industry now)

One of those things is that salty air can rapidly destroy electronics. I made the mistake of keeping a reef tank and a rack server in the same room and had to replace parts of the server that corroded.

It's the exposed connections and how fast I've seen things corrode that makes me nervous.

He's just experimenting with some sand and water. Honestly, I'm really looking forward to see what he comes up with. I can say that the aluminum parts will never be a problem. My entire stand is black anodized aluminum and it laughs at salt. Electronics in any consumer grade version of something like this would have to be waterproofed for sure. But no, it's just like me building a flamethrower in my garage for entertainment. Could I blow myself up? Sure! But the fun is worth the risk!

 

[rhizotron]

It's like a rudder.

Yes it kinda is.

While extremely cool, all those exposed electronics so close to saltwater make me nervous.

I'm not overly concerned about that. This is a mellow setup that won't have much splash or bubbles at all. And the electronic parts are pretty well up off the water. I try to be careful and avoid wasting stuff, but all together the electronics was only about thirty-five dollars.

This is really cool! I would love to see a video. What do you plan on stocking the tank with?

Yep I will try to get a video pretty soon. I think I have a pretty cool idea for live organisms. I've beeb researching and round up plants that grow in seagrass kinds of habitats, but more in the upstream areas of estuaries with moderate salinity around 10-15ppt. So far I have Potamogeton perfoliatus, Eleocharis parvula, Halodule wrightii and Ruppia maritima. Of these, the Halodule is the only actual true seagrass. The Halodule and Ruppia were collected in high-end brackish water and I'm currently reducing salinity for them a bit every few days. The Eleocharis and Potamogeton on the other hand were grown in freshwater and I'm increasing salinity for them in another seperate tank so I can put all four together in a few weeks.

I hope these will grow. If I can get some results, I will start another discussion on them in the macroalgae sub-forum. I have fish ideas too for later this spring if the plants grow.

Potamogeton perfoliatus

Eleocharis parvula

Halodule wrightii

Ruppia maritima

 

[rhizotron]

Quick plant update....

That Ruppia maritima seems to be growing well already with lots of new root and shoot development. I should start a discussion just on it over in the Macroalgae sub-forum.

I wonder about R. maritima as a reef refugium possibility. Apparently more inclined to brackish conditions it does occur in full-strength 35ppt seawater.