The "Hitchhiker's Guide" to the Maxi-Stream mod

[jrcastro]

<a href=showthread.php?s=&postid=6793850#post6793850 target=_blank>Originally posted</a> by Ball
You have to e-mail them. They will then send you a form to fill out and mail or fax. I didnt want to do that so I ended up talking to them on the phone and ordering them that way.

If you are going to mount it to a magnet, then all you need is the swivel bracket. If you want to mount it hanging on the tank like a seio, then you need the entire mounting kit. The swivel bracket cost half as much as the entire kit. The 620 mount is the smallest and holds the maxijet perfectly.

Planning on a magnet mount.
What type of magnet are you using?
How much was the swivel bracket? If you don't mind.

 

[RichConley]

I was just about to post that I think these would work great on the SEIO brackets, and apparantly I got beat to it. How much do the brackets run?

 

[Ball]

I used a Hagen extra large cleaning magnet because of the power and slim profile. People were using these to hold up seio's, so I figured they would work well with the maxijets. They hold good.

The swivel brackets cost me $5 each. The entire mounting kit would have been $10, but you really dont need all those extra plastic parts.

If you shop around, the magnet can be found for under $10, so the entire mounting mod is less than $15. Its worth it to me since you can move the pump anywhere and aim it in any direction with ease.

I plan on putting one of the moded pumps behind the rocks, and the magnet/swivel bracket combo will help out a lot with locating and aiming the pump where I want.

 

[golfbomber]

sorry can someone tell me how many gph the modded mj900 puts out. i dont wanna go through a million pgs of posts . thx.

 

[dhnguyen]

It depends on what type of propellers and how many per mod are used.

single 1.25" Dumas propeller will put out around 1100-1200gph

single 1.25" Nitro or double 1.25" Dumas will put out around 1200-1500gph

double 1.25" Nitro will be around 1800gph

single 1.75" Dumas will be (I'm just guessing on this one since I haven't tested it) around 2500gph or more


D.

 

[jrcastro]

D.

I was able to make a stopper & make it spin correctly now.
I have one question.
It spins fine out of the water & when I put it in the water about 1-2" it works fine as it sucks some air. But when i put it deeper like around 5-6" & doesn't suck air it stops & rattles. & when i lift it closer to the surface & air it works again.

I know in your FAQ's you said that the inlet holes / slots might be the case but in my case i have lots of big slots.

What else could it be?

thanks

 

[dhnguyen]

Do you have a photo of your mod jrcastro?

 

[natual]

<a href=showthread.php?s=&postid=6798309#post6798309 target=_blank>Originally posted</a> by jrcastro
D.

I was able to make a stopper & make it spin correctly now.
I have one question.
It spins fine out of the water & when I put it in the water about 1-2" it works fine as it sucks some air. But when i put it deeper like around 5-6" & doesn't suck air it stops & rattles. & when i lift it closer to the surface & air it works again.

I know in your FAQ's you said that the inlet holes / slots might be the case but in my case i have lots of big slots.

What else could it be?

thanks

Your mod could be at that wierd and perfectly wrong spot where the water pressure at 2" or less will allow it to spin but below that it gets held up.

I kinda had this problem too, alittle different, could be too much friction on the shaft and it stops. '
Orientation seems to be a big one too. A slight kilter and it could stop the whole thing and I do mean SLIGHT.
You could polish the shaft, By letting the propeller out of water and immersing the powerhead portion in a tub and let it run for a while.

Make sure your center brace is the correct distance from the propeller, and it is skinny. You also might have too long of a post propeller PVC.

Most likely you could also enlarge and increase the intake side.
This seemed to help me immesely

 

[jrcastro]

<a href=showthread.php?s=&postid=6798552#post6798552 target=_blank>Originally posted</a> by natual
Your mod could be at that wierd and perfectly wrong spot where the water pressure at 2" or less will allow it to spin but below that it gets held up.

I kinda had this problem too, alittle different, could be too much friction on the shaft and it stops. '
Orientation seems to be a big one too. A slight kilter and it could stop the whole thing and I do mean SLIGHT.
You could polish the shaft, By letting the propeller out of water and immersing the powerhead portion in a tub and let it run for a while.

Make sure your center brace is the correct distance from the propeller, and it is skinny. You also might have too long of a post propeller PVC.

Most likely you could also enlarge and increase the intake side.
This seemed to help me immesely

It could be either of the things you pointed out.
My coupling is approx 2.25" is this too long?
I think it is at that perfectly wrong spot where it won't allow it to spin with certain pressure as you mentioned.

D.
I'll try to take some pics tomorrow

 

[Jon770]

QUESTION:

I recently switched my single Dumas 1.25 to a single Nitro 1.25. First, let me say that I definitely notice a difference...especially when it comes to surface agitation. But this morning when I woke up, I randomly decided to check it out and the propeller was moving EXTREMELY slow and producing very little (if any) flow. I unplugged it and immediately plugged it back in, and it went back to running like a champ.

Any ideas why this happened? Anyone else had this happen to them?

BTW- It's still in the same housing as my Dumas was, which ran perfectly for a couple weeks and can be seen here:

 

[Urabggr]

I made a dual 1.25" Dumas prop version of this mod and was semi-satisfied. But I had a few problems and decided to rebuild the housing. As a was putting it back together, I realized that I have a single 1.75" Dumas prop that I bought accidentally. So, I decided to completely start over and make a single 1.75" dumas prop setup (on a MJ1200). What I'd like to know is how long should I make the housing? Thanks!

 

[coralreefing]

I made my housing 2 1/16 long & the mount adds another 1/4.

The mount is SCH-80 PVC & the housing is a SCH-80 coupling with 5, 3/16 slots.

 

[coralreefing]

I tried the 1 3/4 Dumas prop on a MJ900 with the same housing & it didn't work. It just kept trying to reverse. Has this prop worked for anyone else on a 900?

Also has anyone tried the MJ1200 with dual 1 3/4 props & what were the results?

 

[Timbo]

Has anyone measured the wattage draw of one of these pumps with the different propeller options? I wonder if with the big props it might draw too many watts and potentially overheat. The Tunze 6080 is an AC pump that uses 17w to produce a claimed 2200gph and the maxijet 1200 is rated for 22w. The Maxijet 900 however is measured at only 8.5w so either its MUCH more efficient then a Tunze, Tunze is claiming more gph then the pump actually produces, or the Maxijet is drawing more power then it is rated for. This may not be a problem, but i'm curious if an over-drawing maxijet will last long-term.

dhnguyen- have you measured the flow from a Tunze Stream? I wonder how they compare to your maxi-jet mod in flow and wattage consumption. I'd be particularly interested in the 6080 since that seems to compare the most directly to your modded Maxi's.

Nice work guys! these mods are looking great.

 

[RichConley]

Timbo, its kind of counter-intuitive, but when you put more load on a pump, it draws less power. If you look at the flow curves of a normal pump, as you put more head pressure on it, the wattage draw goes down.


The fact that these seem to be more efficient than the Tunze streams begs the question: Are the Tunzes even that efficient, or do they just appear so much more efficient than anything else because of a fundamentally different design.

I guess what I'm saying is: What if the tunzes are really innefficient prop pumps. I think its pretty obvious that in simple flow situations, the prop style is certainly vastly superior to standard impellars. SEIOs can't really be used as a comparison because they are still basically impellar pumps.

 

[Critter]

I'll take a guess assuming the new nitro is on correctly, that perhaps the entire propeller assembly didn't slide all the way back into the pump and was only getting a portion of the power (not sure how far yours moves along the shaft), and when you powered it off and back on it forced it out and then back in and it seated properly? But just a guess. I had mine stuck in neutral once when we had a few quick power losses. When the power came back on for good, the prop never started. Unfortunately I didn't examine the pump before removing from the tank so not sure what state it was in.

<a href=showthread.php?s=&postid=6799464#post6799464 target=_blank>Originally posted</a> by Jon770
QUESTION:

I recently switched my single Dumas 1.25 to a single Nitro 1.25. First, let me say that I definitely notice a difference...especially when it comes to surface agitation. But this morning when I woke up, I randomly decided to check it out and the propeller was moving EXTREMELY slow and producing very little (if any) flow. I unplugged it and immediately plugged it back in, and it went back to running like a champ.

Any ideas why this happened? Anyone else had this happen to them?

BTW- It's still in the same housing as my Dumas was, which ran perfectly for a couple weeks and can be seen here:

 

[Timbo]

Rich-

The counter-intuitive concept your talking about is true for radial pumps but...

We have to compare apples to apples: we can't compare what a radial flow, ie centrifugal/impeller, pump will do under load to what an axial flow pump will do under load. In an axial flow pump, when you restrict the input, the power draw will go down. By freeing up the input, you will move more water and the power draw will increase. When you restrict the output, the power draw will increase, as a result of backpressure on the propeller.

Either way though, if you put a larger propeller onto the same pump body with everything else being equal, the load increases as a result of moving more water. It's simplest if you think of it like this, the propeller pump will draw more energy the more water it pumps. This is because its doing work. If you restrict the input, less water is being moved, thus less power draw.

This is based on actual observations i've made using a wattmeter and garbage bag to test flow.

I agree with you completely about the question, are Tunze's really that efficient, or are they just capitalizing on the efficiency of an axial flow pump versus a radial flow pump to move large amounts of water in a zero head application?

We're getting close to knowing the answer if you guys are really getting ~2k gph out of a maxijet. All we really need to answer this question is the wattage of a maxijet at this gph, and a comparable bag test of a stream pump. Now we can compare apples to apples and make some conclusions.

 

[Marcelog]

So what are you waiting for Timbo?

Marcelo -

 

[dhnguyen]

Timbo - I would love to test the maxi-mod against a Tunze and find out just what the numbers are. But like most people, I don't have a Tunze lying around (otherwise I would never have done this mod in the first place) If anyone wants to lend me their Tunze though ...


D.

 

[brandon0350]

just a question...do you think an propeller housing could me made to fit inside a bilkhead say for a closed loop to kinda dispurse the flow better? is there a prop less than a inch? that could fit in 1" pvc?