Using Thrusters as wave makers in aquariums

[sawdonkey]

@sawdonkey which Arduino are you using? If it is an Uno R4 with a Renesas microcontroller then it has this issue and you have to update the servo library. I can walk you through that if needed.

Here is a teaser of the thruster housing. So it attaches to the two machine screws where the current nosecone attaches, passes the power cable out, holds three coated magnets inside, and those interface with three coated magnets outside in the outer component.

Buddy is going to help me machine one and I will likely print one as well and see what turns out better. This part, the outboard magnet holder, plus the required long M3 screws, and the 6 magnets, will be what is needed to transform a T200 into a mount-to-glass powerhead.

I have the R4 Wifi, the one with the little LED matrix right in the board.

Your housing looks awesome, however I suspect it won’t allow enough water through and will strain the pump causing it to be noisy. I could be wrong, this was the case for my test housings. Perhaps this I why Abyzz made the cannon so long? More surface area to let water through? I hope I’m wrong, because that design is really sharp!

 

[ravi197699]

@sawdonkey which Arduino are you using? If it is an Uno R4 with a Renesas microcontroller then it has this issue and you have to update the servo library. I can walk you through that if needed.

Here is a teaser of the thruster housing. So it attaches to the two machine screws where the current nosecone attaches, passes the power cable out, holds three coated magnets inside, and those interface with three coated magnets outside in the outer component.

Buddy is going to help me machine one and I will likely print one as well and see what turns out better. This part, the outboard magnet holder, plus the required long M3 screws, and the 6 magnets, will be what is needed to transform a T200 into a mount-to-glass powerhead.

awesome design, please share pictures when you have printed version,

 

[ravi197699]

I have the R4 Wifi, the one with the little LED matrix right in the board.

Your housing looks awesome, however I suspect it won’t allow enough water through and will strain the pump causing it to be noisy. I could be wrong, this was the case for my test housings. Perhaps this I why Abyzz made the cannon so long? More surface area to let water through? I hope I’m wrong, because that design is really sharp!

now that I am thinking about it, thrusters suck water from behind and sides are solid wall, you will need the rear side only and remove the cage, if you keep the rear section of the design then it will screw in behind the motor and 3 magnets are enough to old the thruster secured on the glass, just thinking out loud,

 

[Reef-Engineer]

Plan is to use the three magnets to hold it to the glass (to the three magnets on outside of glass). Sawdonkey is right, we want the most flow possible while still keeping critters out. The cross sectional area of the thruster tube is about 11.5 in^2. These flutes have a cross sectional area of about 14 in^2, but there are boundary effects to consider. I plan on modeling it with more/larger flutes since the outside cage is no longer structural in any way, its just there to keep critters out.

Originally I had intended to mount the thruster using the 4 screws at every 90 degrees around the thruster housing, but those are self tapping screws and will not tolerate repeated assembly/disassembly (poor design feature in my opinion). So now we have to mount using the nosecone mount which uses machine screws and 316 SS inserts.

All structure is the back magnet panel, and the pedestal that interfaces with the thruster motor mount (where old nose cone went).

It is also super easy to make the cylinder longer, increasing the surface area of the flutes. There will be some trial and error, and the harder you push the thruster, the larger the intake surface area will have to be. What is enough at 8V wont be enough at 16V or 20V, that is for sure.

I'll share pics once I get one of these made, I also am working on a program that you can use a switch or buttons to select smooth ramp up/down, random, or constant using potentiometer set max speed. Ravi has a lot of that already, but I'll post my code once it is done either way.

@sawdonkey PM me your email and I can send instructions for fixing your arduino.

 

[Reef-Engineer]

Outside more heavily fluted, a few other significant changes. Going to machine and print it.

A few points:
1. This mounts where the old thruster nosecone used to mount with two M3 machine screws. That ramp in the middle is to allow water into the rear of the motor and the power cable to exit.
2. The three circles in the back are for three neodymium magnets (1" diameter, 1/2" thick, coated, waterproof) and there is a matching plate that goes outside and holds the other three magnets. They will DEFINITELY be strong enough. I might have overdone it, they each have 28lbs of holding strength. Scary strong.
3. The walls of this cylinder are just filters/guards to keep critters out of the thruster. The cylinder length and pedestal mount length are dictated by how much area needs to be fluted to allow enough water in that the thruster has no problem running and can run quietly.

So I am going to try and print a couple, and then machine a couple. I have the .stp files that I can share if it works out. I think this is going to be sick.

Now onto the program.

 

[ravi197699]

Outside more heavily fluted, a few other significant changes. Going to machine and print it.

A few points:
1. This mounts where the old thruster nosecone used to mount with two M3 machine screws. That ramp in the middle is to allow water into the rear of the motor and the power cable to exit.
2. The three circles in the back are for three neodymium magnets (1" diameter, 1/2" thick, coated, waterproof) and there is a matching plate that goes outside and holds the other three magnets. They will DEFINITELY be strong enough. I might have overdone it, they each have 28lbs of holding strength. Scary strong.
3. The walls of this cylinder are just filters/guards to keep critters out of the thruster. The cylinder length and pedestal mount length are dictated by how much area needs to be fluted to allow enough water in that the thruster has no problem running and can run quietly.

So I am going to try and print a couple, and then machine a couple. I have the .stp files that I can share if it works out. I think this is going to be sick.

Now onto the program.

this will be awesome if this works out, I can share some ideas on magnets that will go in the tank, I am not too concerned about the outside ones they will be easy to waterproof,

 

[Reef-Engineer]

this will be awesome if this works out, I can share some ideas on magnets that will go in the tank, I am not too concerned about the outside ones they will be easy to waterproof,

I bought six of these. its $80 in magnets, and they are absurdly strong, so you could probably save money and get weaker magnets, but these are coated, wont rust, and three of them can hold up 90lbs lol

mega magnets

Buddy 3D printing the mount now. Machining buddy is slower lol. Also working on a mega program with a 3 way switch to allow ramping, random, or steady flow with potentiometer to set max speed.

At this rate I will have flow long before I have a fishtank...

 

[ravi197699]

I bought six of these. its $80 in magnets, and they are absurdly strong, so you could probably save money and get weaker magnets, but these are coated, wont rust, and three of them can hold up 90lbs lol

mega magnets

Buddy 3D printing the mount now. Machining buddy is slower lol. Also working on a mega program with a 3 way switch to allow ramping, random, or steady flow with potentiometer to set max speed.

At this rate I will have flow long before I have a fishtank...

this is great, looking forward to see the progress,

 

[sawdonkey]

I’m fully up and running with a lot of help from @Reef-Engineer. He wrote a sketch that works perfect for me. I’ve got it ramping up and down smoothly over about ten seconds,

The thruster still whines a little louder than I’d like, but I can live with it. The flow potential of this thing is WAY too much for my tank, but toned down, it’s great. It kicks up detritus my other powerheads have not.

Still need to come up with a permanent solution for mounting it.

I need to clean up the fish room now because I’ve diverted my attention to this project for a little while now.

 

[Reef-Engineer]

I have a 3D printed version on the way, and a Delrin machined version in the works. Here is a teaser of the mount. I'll post when I get it and assemble and let you know how it is looking. If the 3D printing is strong enough, then this would become an easy mod. If it isn't then I am sure my machinist buddy would sell copies of the machined variant.

I am 90% of the way through a program to facilitate night mode, random, ramp up/down, steady, and reverse-clear-out. I need to buy some switches and an electronics box to get this all organized so it doesnt look like a science project.

 

[Reef-Engineer]

ok I have a code that does steady state, rampupdown and random. Ravi I'll send it to you as a word doc in a message, let me know what you think. You need a 3 way switch to send ground to either pin 4 (steady flow), 7 (ramp up/down), or 8 (random). All programs set max speed with potentiometer and use 1550 as min speed. I didnt build in a periodic reverse yet, but that isnt hard to do, just another millis functon with a really large gap.

I'll send pics of assembled thruster when parts come in this week (assuming all goes well!).

 

[ravi197699]

I have a 3D printed version on the way, and a Delrin machined version in the works. Here is a teaser of the mount. I'll post when I get it and assemble and let you know how it is looking. If the 3D printing is strong enough, then this would become an easy mod. If it isn't then I am sure my machinist buddy would sell copies of the machined variant.

I am 90% of the way through a program to facilitate night mode, random, ramp up/down, steady, and reverse-clear-out. I need to buy some switches and an electronics box to get this all organized so it doesnt look like a science project.

looks good, when will you test with thruster, please share pictures, just curious to see how it will look with thruster?

 

[ravi197699]

ok I have a code that does steady state, rampupdown and random. Ravi I'll send it to you as a word doc in a message, let me know what you think. You need a 3 way switch to send ground to either pin 4 (steady flow), 7 (ramp up/down), or 8 (random). All programs set max speed with potentiometer and use 1550 as min speed. I didnt build in a periodic reverse yet, but that isnt hard to do, just another millis functon with a really large gap.

I'll send pics of assembled thruster when parts come in this week (assuming all goes well!).

Thank you so much, please share the pictures of the parts and final product, I will try to do same with my new build and current thrusters, It will be helpful to see pictures for how you connected everything, great work mate,

 

[Reef-Engineer]

Ok, hardware on the way and silicone rubber sheets to attach to each side at glass interface.

Now i just need someone with a fishtank to try it…

Also got electronics box to tidy those bits up, and switches for modes.

 

[ravi197699]

Looks great mate, is there any way to shorten the length of the housing so the thruster sits flush in the front with gaurd? it will look more neat and did put your hardware box together and give it a try yet?

 

[Reef-Engineer]

Looks great mate, is there any way to shorten the length of the housing so the thruster sits flush in the front with gaurd? it will look more neat and did put your hardware box together and give it a try yet?

Hi Ravi, so I can experiment with that, but the housing needs to be long enough so that the intake flutes have a large enough surface area to not starve the thruster of flow. This was a somewhat safe length. I know that the thruster will get louder if it is having to work hard to pull water, so I build in a lot of venting. If this model is silent, I can basically shorten the internal pedistal so that the thruster sits deeper in the housing.

This is why the panta rhei and abyzz units are pretty long, you need enough area to suck water in from.

Life and dadding took most of my time this weekend but I hope to get the electronics packaged today or this week in the evenings.

I also found out my neighbor has a 3D printer, so I might buy some PTEG and a six pack and speed prototyping up a bit!

 

[ravi197699]

Hi Ravi, so I can experiment with that, but the housing needs to be long enough so that the intake flutes have a large enough surface area to not starve the thruster of flow. This was a somewhat safe length. I know that the thruster will get louder if it is having to work hard to pull water, so I build in a lot of venting. If this model is silent, I can basically shorten the internal pedistal so that the thruster sits deeper in the housing.

This is why the panta rhei and abyzz units are pretty long, you need enough area to suck water in from.

Life and dadding took most of my time this weekend but I hope to get the electronics packaged today or this week in the evenings.

I also found out my neighbor has a 3D printer, so I might buy some PTEG and a six pack and speed prototyping up a bit!

Thank you bud, I am waiting for 2 thrusters build, I will try to use your design and code and see how it behaves in my tank, so far loving my t500 thrusters,

 

[Reef-Engineer]

Cut silicone rubber to go between thruster and glass, mounted magnets, got felt to go between outer piece and glass to protect it.

Now to finish electronics then ill share that, then find a tank to test in…

 

[ravi197699]

Cut silicone rubber to go between thruster and glass, mounted magnets, got felt to go between outer piece and glass to protect it.

Now to finish electronics then ill share that, then find a tank to test in…

look great, silicone pad will absorb any vibrations from the thruster, looking forward to see electrical progress

 

[Reef-Engineer]

Heres a link to a short vid describing the electronics box thus far