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

[hancockrich]

k...i just looked at it and wow...but how does it work...do ya have to cut a hole in the tank..or is it some kinda of magnet??...anyone know??...thz...rich

[headshrink]

I am pretty sure it is a magnet.

[dhnguyen]

It's what you would get if you take the maxi-stream propeller mod and marry it with a magnetic stirrer

Pretty novel idea really using 2 existing technologies together like that. I'm surprise though no one thought of it sooner.


D.

[dhnguyen]

I will be very curious as to what would happen to Tunze sales numbers when this Vortech powerhead is released though. Rumour has it that the price of a Vortech though not cheap will be less than a Tunze.

[melev]

Right. No drilling required. I honestly can't wait to get one as I've got the perfect spot in mind. There is a lot of information in a thread over in the IceCap forum if you want to read it.

[larryl]

Hi D. -

Originally posted by dhnguyen
MJ900 mod w/fancy slots

It's hard to tell from this pic bit it looks like the prop sits at about 1/3 of the length of the slotted area (from the right). Is that right? If so, can you tell for sure that the slots to the left of the prop (i.e. downstream) are pulling water in, rather than getting water pushed out? If water is getting pulled in, must be getting some sort of eductor effect...


Larry

[dhnguyen]

Actually Larry, the prop blades begin just about one inch below the cross brace so no they's not sitting 1/3 of the PVC pipe length

And yes you're right it is using the same principle as eductor in that it sucks in water in a vacuum of sorts and then pushes out in a stream.

[DonJasper]

Nice work dhnguyen.

Originally posted by Urabggr
Is there any reason that mj1200's aren't used? Or is it just because you didn't have one. I ask because I plan on doing this mod on my 1200 but haven't really seen many people using the 1200. Is it too strong? Thanks!

Once you get prop spinning around it doesn't matter any more. The bigger the prop the more water moved. On weaker powerheads you have trim off the ends of the prop to make is smaller so it will spin. Otherwise the prop just flutters back and forth making lots of noise but moving no water.

It can make a BIG difference.

[hancockrich]

bump...this should stay on the first page....and up top...rich

[GSerg2]

Why do you have an inch space between the props and the brace? Trying picture it in my head, it seems that if the prop was closer it would be better because it would hit the stop block quicker if the impeller turned the wrong way on startup. I'm not questioning your design, just trying to understand fully what is happening. I probably have a flaw in my thinking on this.

Thanks again for this thread. I have my parts ordered and hopefully they will be here by this weekend!!!

[dhnguyen]

well you do want to allow some room for the impeller to move back and forth as it wil do this very rapidly upon startup to right itself. Also the one inch tolerance is not neccessarily exact either. One inch from the cross brace to the prop but also factor in the stopper underneath the cross brace which would hit the prop long before it actually comes in contact with the cross brace itself. So in actuality it's more like 3/4 inch.

But I do suppose that you can leave a smaller tolerance if you want to. It's just easier to measure, follow, and duplicate 1 inch than say 5/16 inch

[GSerg2]

Gotcha, thanks again.

[Reefer madness]

Great thread! Thanks for compiling everything.

FWIW, I have a section of sch 80 1.5" PVC (gray). The ID of the schd 80 pipe is approx .005" too small to fit over the maxi-jet body. I am using MJ 1200's for measurements, yours may vary.

I figure a flapper wheel will eat up that dimension pretty quick. The schd 80 pipe color almost matches the MJ perfectly. I'm going to give it a try.

Scott

[dhnguyen]

You could take a Dremel and bore it out a little to make it fit the MJ body. Wouldn't be too hard to grind down 0.005" on one end

[Reefer madness]

Even better than a dremel:

Flapper wheel

This should make it easier to keep the ID round since it should only require a quick sanding. Making the pipe out of round could lead to centering issues with the impeller. In my mind, at least.

Question though: Is there any particular reason why you put the bearing from the MJ on the end of the carbon fiber rod? It seems to me that you could cut the rod flush with the end and make it more aesthetically pleasing. Am I missing something?

Thanks,
Scott

[dhnguyen]

No reason really. I actually kinda like the look of the bearing on the outside of the cross brace like that. And I have this thing about not having any small extra parts after assembly
Something about a loose small rubber bearing lying around kinda gnaws at me I guess

Used to work on motorcyles and that "Uh oh where did this come from..." after I completed rebuilding an engine gets to me big time

[Francisco Leal]

Good work! Thank you for doing this.
Could you tell me how much flow have this maxjet 900 after modifications? How do you make to measure?

[dhnguyen]

That part I don't know just yet. Haven't tried measuring to get an estimated flow rate yet. Melev suggested using a thin plastic bag connected to the output and time how long it takes to fill it then measure what's in the bag.

I would assuming just by the look anf general feel of things, the flow is improved at least 3 times if not much more compared to a stock MJ pump.


D.

[schanz]

How did you do the "mod mount" so that the ph sits horizontally? Did you glue the small beveled piece to the top of the ph?

[dhnguyen]

Yep

[wildcats]

Back to the grey pipe for a minute, most home improvement stores carry grey pvc pipe used for electrical conduit. Its cheaper than schedule 80. I think you'll find it much easier. Also, when used for plumbing, they have lots of fittings available in odd angles which sometimes come in particularly handy. Check it out

[dhnguyen]

Guess what I found

SCH40 Gray PVC pipes

http://www.usplastic.com/catalog/pro...uct%5Fid=16587

[billpa]

For the MJ900 version...was a test cap used for the mount to the MJ900 or did you cut that groove our yourself? If so, do you have any info or photos on how to do that? Nice job BTW!

Thanks
billpa

[dhnguyen]

Nope no PVC test cap on the MJ900 mod shown on page 1.

Also there I posted how to do the groove

Cutting the groove. For this I am using a 10" miter saw with a 7" fine toothed blade. At the highest height setting, the miter saw will come down just enough to cut into the 1.5" PVC pipe halfway through the plastic, making it ideal for cutting the groove. For those of you who chose to use the PVC test caps instead, you can skip this.

You can probably do it with a Dremel cutoff wheel too or even a hack saw if you don't have access to power tools.

[billpa]

okay cool...but you could use the test cap instead...correct? Only reason why I ask is because you only used the teset cap on the 400. I dont think the models vary in size but wanted to make sure.

Thanks!
Bill