Another MJ mod that cranks

[surfjeepzx]

I've been refining how I make the housings and that has shown to be the biggest single improvement with regards to flow from a mod'd maxi. I built 2 this morning, one has the white Dumas 3004 prop and the other has the yellow Octura 1240 . The 1240 flows about 3x the amount the 3004 does with the same housing just swapping of prop assemblies. Who knows maybe more? I just stick my hand in front of the running pump and gauge the flow by the amount of pressure exitting the pump. The 1240 prop has considerably more pressure than the 3004.

The 1240 prop moves some serious water and I wouldn't recommend this mod for anything under a 180. I run 2 mod'd 1200's with the 3004 in a 135 and that seems to be the limit before you start moving the sand from across the tank. The 1240 I placed in the tank just to compare and it was ridiculous how much water this thing moved. Imagine the stock mj1200 flow from the nozzle if you placed your hand in front of the pump. Now try to imagine that amount of flow exitting that big ole area of the mod'd mj1200 with the 1240 prop...and then some.

Here's how I configure the prop/ magnet assembly. I found this to be the best way I've tried, and I've tried a lot of different set-ups. Running the magnet with the stock insert against the stock bushing. .098 carbon fiber rod allows use of the stock bushings. I use a .110 carbon fiber tube cut and joined using the airline tubing that comes with the pump. I'm sure this is nothing new to those that do many of these.

<img src="http://reefcentral.com/gallery/data/500/87822P6030164.JPG">

Here's a shot of the housing. I make the centering peice from acrylic with a hole drilled to accept the bushing. I dremel the support down so there's very little that can alter or block the flow. I also dremel the inside of the housing to smooth water flow. Where the pipe and coupler meet is a smooth transition.

<img src="http://reefcentral.com/gallery/data/500/87822P6030158.JPG">

Notice the fangs, that's my Mitzi always in the way.

<img src="http://reefcentral.com/gallery/data/500/87822P6030162.JPG">

You can see the taper on the inside of the housing if you look along the inside top edge of the housing. This pump has the 1240 prop. I only ran it for about 5 minutes in the tank.

<img src="http://reefcentral.com/gallery/data/500/87822P6030156.JPG">
<img src="http://reefcentral.com/gallery/data/500/87822P6030155.JPG">

 

[ReefForBrains]

What about a better jig for making your intake slots?

Not downing your work ,but with a cleaner jig and a better curfed saw you will ge more inflow.

I understand theres only so much meat to clean then the skeleton becomes the weak link, but form the profile shots in the pic theres some room for some serious inflow with some cleanup to the fins.

 

[mypurpletang]

Nice going.

 

[surfjeepzx]

<a href=showthread.php?s=&postid=10072295#post10072295 target=_blank>Originally posted</a> by ReefForBrains
What about a better jig for making your intake slots?

Not downing your work ,but with a cleaner jig and a better curfed saw you will ge more inflow.

I understand theres only so much meat to clean then the skeleton becomes the weak link, but form the profile shots in the pic theres some room for some serious inflow with some cleanup to the fins.

No downing taken,
I've found that by leaving 3 spine sections on the couplers it's more sturdy when assembling and disassembling the housings. I've found that about a 1/4" in the spines is thin enough. Any less and you risk breaking the housing when tinkering with it.

I do have a system of taping off the areas that I don't want cut. Truthfully though, if you could witness the amount of propulsion from these mods with the yellow props it's quite impressive. I'm making these for a friend who's installing them in his customers tanks and I've had nothing but compliments on the performance. He's more familiar now with the performance of the different props so he tells me what props to install based on the tank they're going in.

Like anything else I'm getting better with each set I make. I may go up to an 80 tooth blade and see if the cuts are any cleaner. I usually set up and make a run of 10 housings. You should see the pile of plastic shavings when I'm done. :eek1: