180 gallon build: Modular control system, 3D printed equipment, open-source

[jrhupp]

Awesome stuff..

Thanks!

I'm still really impressed with your skimmer design. I keep kicking around the idea of building one myself.

I haven't had the time to even finish up my kalk reactor, though

I'm glad you like it. I have been quite happy with it and would absolutely love to see someone else build one.

I do have some things I want to change related to the air intake though. The current design has clogged a few times on me. I am suspecting this is mostly just an issue of an old dusty house (1968) that has the windows open a lot, and would not be an issue for someone in a modern home. But either way, I need an intake filter. So the plan is at some point to model up a filter assembly that screws on in place of the current intake.

 

[BigDave]

I'm digging through the links on this post, but can't find it... Where's the links for the skimmer stuff?

I have a chunk of clear PVC sitting in my garage and if it's the right size, I might start printing the parts.

 

[itri4ever]

First of all...just pure awesome, that's all I have to say. I have the pc, and actually made my own skimmer by molding different pieces in the oven before I got a 3d printer. I now want to print yours. My question is this. When I import your design into skeychup it bring it in as a roughly 6' diameter pipe and not 6". What am I too g wrong?

Any help would be greatly appreciated!

 

[jrhupp]

First off, sorry for the slow replies (below). I have been traveling and have not had a chance/energy to get to this.

I'm digging through the links on this post, but can't find it... Where's the links for the skimmer stuff?

I have a chunk of clear PVC sitting in my garage and if it's the right size, I might start printing the parts.

Here are links:
Skimmer model in SketchUp
Zip archive with properly scaled STLs for all the parts

First of all...just pure awesome, that's all I have to say. I have the pc, and actually made my own skimmer by molding different pieces in the oven before I got a 3d printer. I now want to print yours. My question is this. When I import your design into skeychup it bring it in as a roughly 6' diameter pipe and not 6". What am I too g wrong?

Any help would be greatly appreciated!

Thanks. Glad you like it, and happy to help.

All the parts are modeled 10x. SketchUp does not do well with complex geometry when parts are small; lots of holes in surfaces. Modeling at 10x (or greater) helps greatly with this. You simply need to scale the parts by 0.1 before exporting them.

Normally I rescale before posting parts, but left these large in case others wanted to modify them. I have updated the notes in the model to reflect the scaling.

I also added some notes on the length and sizing of the acrylic tube I used to build the skimmer (OD, wall thickness and lengths).

 

[itri4ever]

That is perfect, thank you for the modifications and help. I started printing out them by resizing them to fit the 6" tube, but i may reprint them based of your sizing to make sure they fit properly.

 

[itri4ever]

jrhupp: Just out of curiosity - what infill did you use for printing your parts?

 

[jrhupp]

jrhupp: Just out of curiosity - what infill did you use for printing your parts?

Typically 30% infill with a 1 mm thick wall.

 

[itri4ever]

What would the easiest way be to remove the fans on the cone, or make them thicker? I have printed that part three times now and every time the layers peal apart during printing. I think it may be because i dont have a heated chamber to keep the ambient air warm to prevent the abs from cooling to quickly. Any help with sketchup would be greatly appreciated. Thanks!

 

[jrhupp]

What would the easiest way be to remove the fans on the cone, or make them thicker? I have printed that part three times now and every time the layers peal apart during printing. I think it may be because i dont have a heated chamber to keep the ambient air warm to prevent the abs from cooling to quickly. Any help with sketchup would be greatly appreciated. Thanks!

I don't know that there is an "easy" way; SketchUp falls pretty flat when it comes to modifying complex geometry. If you make hidden geometry visible you will be able to see edges for all the faces and then you can get some idea on how to modify it most easily. Probably adding a line on each side and removing the outwardly curved portion of the fin would be the simplest aproach.

You will want to leave some "fin" on the cone though. They are what gives grip when disassembling it down the road for cleaning. Once a little salt creep builds up in the threads the value of the fins becomes very apparent.

Have you tried putting a box over the printer? It is simple and holds in the heat, which may be all you need to ward off the layer separations. I don't actively heat my printer; its just in a plywood box with a few fans on the steppers to keep them "cool" and the heat spread around.

 

[kenneth wolfe]

Just received my multi material kit from prusa.. What a mess

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[Zephrant]

Let us know how it goes. I've been slightly considering it for my Monoprice I3. Didn't really want to figure out how to make it work on my printer, but would really like disolvable support.

 

[jrhupp]

I have been working on a new kalk system for my top off. The old one was a passive design and built for my old 50 gallon system. Originally it was fine on this system, but its too small at this point. So time for something bigger.

This reuses a bunch of stuff I designed for the printed skimmer (and the left over acrylic tube I had from building it). Here it is assembled and ready to install:

The drive system is all built from stuff in my spare parts bins. I think everything is still available somewhere, though a few of the parts are obsolete. It is however pretty generic, so I think it could be easily reworked for other components. The power supply is adjustable voltage and the bracket that it all mounts to is pretty simple and easy to modify to accommodate a range of steppers.

The drive is magnetically coupled with some rare earth magnets. Sealing the magnets in the drive wheel and impeller is done with a two part approach and solvent welding the pieces together. There is a socket and cup. The magnet goes in the cup and this gets solvent welded into the socket. Then the whole thing gets vapor polished. It is yet to be determined how well the sealing went, but I feel pretty confident about it. You can see the magnet assembly in the drive wheel in the above image (or in the SketchUp model linked below). I used black ABS for the cups to give it some contrast.

There is a fair amount of resistance to overcome when engaging the impeller, which leads to it becoming decoupled from the drive wheel if it starts at full speed. It stills spins in this case but slower than the drive wheel does. The solution was a soft start:
<iframe width="560" height="315" src="https://www.youtube.com/embed/lUsUWRp8eP4" frameborder="0" gesture="media" allow="encrypted-media" allowfullscreen></iframe>

I have not implemented the full control sketch for it yet. Right now, I just have it set to run for 15 seconds once an hour. So far so good. But I will implement something a bit more feature rich at some point to control it.

Here it is installed in the sump:

If you want them, here are the source files for what is shareable now:
SketchUp model
Eagle files

P.S. In the sump picture, you can also see an intake modification I am testing on the skimmer. I am using this for a fresh air intake from my roof. I looked at some intake filter designs for dealing with my old dusty house and the resulting intake clogs, but didn't like any of them (or there associated maintenance). So I opted for trying an intake outside and high above the ground. We shall see how it goes long term.

 

[BigDave]

That looks pretty nice. It makes me want to finish my kalk stirrer.

I had a lot of other projects come up which made me stop work on it.

Now I'm running into an issue with my printer that I need to fix. If it's not one thing. It's something else.

I think what is keeping me from working on my kalk stirrer is the thought of screwing up the $32 piece of PVC plate I bought for cutting the parts out on the CNC machine.

 

[Zephrant]

Very nice. I'd suggest that you could greatly shrink the fins on the stirrer. A 1"x1/4" rod stirs a 6" column just fine, up to 18" or so high.

Maybe even change to a standard Teflon stirring rod, then you would not have to deal with sealing magnets at all.

All printed in ABS then?

 

[jrhupp]

Very nice. I'd suggest that you could greatly shrink the fins on the stirrer. A 1"x1/4" rod stirs a 6" column just fine, up to 18" or so high.

Maybe even change to a standard Teflon stirring rod, then you would not have to deal with sealing magnets at all.

All printed in ABS then?

I agree on shrinking the impeller. Size was not based on much (any) testing and it would work just as well much smaller. But as it works quite well as it I likely won't remake it.

I considered a stirring rod design too, either printed or off the shelf. Either would certainly work well too.

Yes, ABS.

 

[jrhupp]

That looks pretty nice. It makes me want to finish my kalk stirrer.

I had a lot of other projects come up which made me stop work on it.

Now I'm running into an issue with my printer that I need to fix. If it's not one thing. It's something else.

I think what is keeping me from working on my kalk stirrer is the thought of screwing up the $32 piece of PVC plate I bought for cutting the parts out on the CNC machine.

Thanks.

I know the feeling on screwing up costly materials. I have a massive roll of copper sheet that has been setting in the shop for years. Every time I think of something to do with it I decide the project is not worth it because I know if I mess it up or come up with something better there is no way I buying another roll.

 

[NubbsJRN]

Have you experimented with Petg yet? I am floundering trying to make a decision on if I want my submersible prints ABS or petg.

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[reefinnewb]

Looks great! Will this skimmer be too large for my 70 gallon total system? Considering I've had a printer for a while, this would be awesome to print.

 

[jrhupp]

Looks great! Will this skimmer be too large for my 70 gallon total system? Considering I've had a printer for a while, this would be awesome to print.

Probably, at full scale and full speed. I'm using it on a 200+ total gallon system.

The design is quite tunable. So I think you could pretty easily dial in for a smaller system. You might build the body a bit shorter as well.

 

[Leif]

well now I have ordered a new 3d printer.... this thread is fantastic, although expensive for me Filament is also on the way I ended up with a tevo Tornado....