MP60 exhaust redirect - 3D printed shroud.

[ffiren]

I've got a large peninsula acro tank and am struggling with flow at the open end. I've used Claude Fable5 to run a fluid dynamics simulation on optimal shroud design, so I can redirect the flow 90' across the bottom of the tank. Gyres would probably work better but they are a pig to maintain and I want this hidden in my scape. If I had my time again, I'd drill the tank and put a closed loop in.

My research shows Black UV resistant PETG is the filament of choice. I've also found 3D models for replacement shrouds but nothing that redirects the flow like this.

Anyone know of anyone that's done something similar? I'm expecting ~30% loss of performance and will install a bracket to prevent the dry side from detaching and entering the sump! I'm also expecting increased wear and tear of the bearings due to the atypical mount. I run bare bottom for maximum flow so there's no risk of debris fouling the pump.

Still, looks like an easy way to address my flow issues! - If it works!

I'll add the STL file here when it's done running simulations. Be good to know if anyone else has tried this before to save me replicating work?

 

[ffiren]

I have an acro-dominant peninsula and wanted serious flow at the open end
without hanging a gyre on the view panel. The plan: MP60 through the bottom
glass (bare bottom, dry side in the cabinet above the sump), with a printed
replacement for the wet-side cage that turns the vertical discharge 90° and
fans it into a wide sheet aimed back toward the wall end — hidden inside the
rockwork.

Instead of guessing the duct shape, I ended up going full nerd: a lattice-
Boltzmann CFD solver running locally, driven by an optimization loop (a local
LLM proposes candidate geometries, my machine simulates them — dozens of runs,
including full 1.8 m tank-scale sims with rockwork in them). A few results
that surprised me and might be useful to others:

- **Turning vanes made the elbow worse.** All the HVAC-style vane/louver
designs lost badly to a plain swept bend (loss coefficient 0.19 vs 0.6–2.4).
At powerhead scale, vane friction and wakes cost more than the separation
they prevent.
- **The widening fan absolutely needs vanes though** — without them the flow
tunnels straight out the middle instead of spreading into the 90° arc.
- **Where the exit sits beats how the duct is shaped.** If the outlet fires
at rockwork taller than itself, the flow just churns in the gap and dies —
every geometry, every time. The exit needs to clear the rock directly in
front of it by a couple of cm. Sheet angled 15° at the floor then sweeps
the sand and wraps over the scape; 25° just face-plants into the rock.
- The final part is 179 mm tall off the glass, keeps ~97% of the pump's flow
(per a prop-stall derating model), prints in one piece in PETG with
supports only under the fan, and bayonets onto the wet side exactly like
the stock cage (the mount is the stock cage mesh from asadler99's free
"Ecotech MP60 Cover" on Cults3D — its Private Use license means I can't
redistribute the mesh, so the repo has a one-command script that rebuilds
the STL from the 3MF you download from Cults yourself).

Fair warning: this is simulation-driven design, 2D slices with a turbulence
model — great for ranking shapes, not gospel for absolute numbers. It hasn't
been wet-tested yet; printing this week, will report back with PAR-meter…
sorry, flow-meter results and detritus observations.

Everything is on GitHub (the parametric generator, the CFD solver, the
whole optimization log):

https://github.com/ffirenmatana/mp60-flow-shroud
Photos attached: the part, a cutaway of the internals, and the tank-scale
flow simulation showing the sheet wrapping over the scape.

 

[ffiren]

Fits perfectly. Feels solid. Test run at 10% flow in a bucket didn't rip it apart.

Currently soaking in RODI for a day while I print a better dry side bracket - don't want that in my sump.

 

[ffiren]

The combo work a treat. Got nice flow back towards the wall and under the scape.

Attached the bracket I made for the dry side. Big pads for adhesive tape. Doesn't contact the motor in any place. The dry side has a couple of mm clearance so it hardly moves if you remove the wet side.

Can't wait to see the shroud purple up - when that happens I'l stick some fags to it

rename the zip to 3mf and you're good.









EDIT: If anyone prints this - this is for the thin shim. You will need to add 6mm for the medium shim and 12mm for the thick one.

 

[ffiren]

Running at 40% with no issues... I'll have to figure out a way to better hide it!

 

[ffiren]

Self-conscious I'm shouting into the void!

Ran another 90K fluid sims after seeing the initial model works. Managed to shrink it down by 2/3 without compromising dispersion pattern.

Settled on the most compact solution (low266), the optimal two-part solution (v5w) and the sub-optimal, but one-shot variant of the optimal solution (v5). The sims do not recommend you go for the one-shot!

I'll put future updates directly on GitHub given the lack of interest here

https://github.com/ffirenmatana/mp60-flow-shroud

 

[pooootiqe]

This is some serious stuff! Great work! Any idea how the performance is compared to a large gyre?

 

[Justfebreezeit]

Very cool solution to the far end peninsula problem.

 

[ffiren]

This is some serious stuff! Great work! Any idea how the performance is compared to a large gyre?

For just cleaning the floor? Definitely wont be as good, but it wasn't designed for that. I wanted ~0.42m/s flow over the hard to reach end of the peninsula with enough flow angled at the bare bottom to prevent detritus accumulating under the rocks. I also didn't want the gyre cable or associated maintenance.

V2 is in the tank now - this is as small as I can get it without choking the flow. I can tolerate this and it wouldn't take much to put a rock donut around it. Bit of Monti on top and it may disappear...

V5 is on the printer - 29hr print . That's the 'optimal' design, but I suspect I wont like how obnoxious it will look.

 

[ffiren]

The v5 oneshot is just about done. Made some changes to infill the gothic arches on top. They’re great for stability when printing, but they trap detritus. Having a flattened top means mounting Monti etc will be easy and hopefully it won’t trap as much crap.

Went through all the data again and the two-piece v5w is significantly better at sweeping the floor. It’s not even close. I’ll print that next as it was the optimal design found when modeling, but it needs the 40 width to effectively put a sheet across the bottom in my tank. I guess, just like a gyre. I didn’t print it before as I thought it was taller and I’d prefer to make it as unobtrusive as possible.

In my Cade 1800 peninsula, the low266 model effectively clears out a good 90cm of the floor in front and seems to sweep around the rock work. I’ve also got more polyp extension than ever at the dirty end of the tank now.

I’ll test the v5 and v5w but suspect I’ll revert to the low266 as it works, is easier to hide and the coral response is great. I’ve no doubt the v5w would be better, but I don’t think I need better. The MP60 is overkill as is, but I needed the clamping pressure on my thick glass.

There’s a few nasty overhangs that resulted in a few failed prints, but this is my first ever printing project and I’m still learning the slicer. Fortunately Fable5 can do the slicing and ray cast for support issues so I’m confident it’s all resolved. The difficulty was in clearly articulating the prompts when referring to complex geometry. I’ve got 3mfs if anyone wants them. I can’t put them on GitHub due to licensing issues with the original fan shroud I used to get the mounting geometry correct, but I’ll make a google shared link for those that ask.

Niche project but it relatively cleanly fixes the ‘end of peninsula’ problem for those prepared to throw an MP60 at it

Overall, I’m really happy.

Next project: I ported apex fusion over to ESPHome. I plan to replace my two A3Pros with diy controllers for better probe support and therefore reliability. Got everything ready except for a few empty nights for soldiering. Happy reefing guys!

 

[ffiren]

This is some serious stuff! Great work! Any idea how the performance is compared to a large gyre?

Simulations claim the v5w (only just realised w = wide) will cover 46% of my tank floor and that’s despite the rocks acting as obstacles. That’s not bad for a 1.8M tank.

I’ve also realised the Core One L can almost certainly do it in one print. The 2D printable diagonal is 4mm greater than the shroud.

I’ll use a high flow 0.6mm nozzle to knock one out in cheap PLA before committing another spool of PETG. Report back in a few days!