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

[dhnguyen]

<a href=showthread.php?s=&postid=6801708#post6801708 target=_blank>Originally posted</a> by 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?

Um... How would you spin the propeller? The force of the water output alone isn't enough I don't think and how would you keep the propeller centered? It needs an axis to spin.

Yes there are propellers 1" or smaller but I don't see how this is viable on a closed loop.

Your best bet for a closed loop is adding eductors IMO.

 

[jrcastro]

Need help guys.

Still having the same problem with my Mod. MJ1200 w/ 1.75" prop in 1.5" coupling.

Problem is that when I put pump in deeper water it rattles & stops working, but when i put near surface it works fine as it pulls air in.

I tried the mod on 2 different MJ 1200 bodies & get the same effect.

Anyone ever have this happen?

 

[brandon0350]

i was just trying to disperse the flow with out enductors because i dont think they can be used on an oceanmotion im sure a few thousand gph could make the props spin but now that i think about it props less than 1 inch would probobly be pretty insufficient i was just a thought

 

[dhnguyen]

<a href=showthread.php?s=&postid=6801890#post6801890 target=_blank>Originally posted</a> by jrcastro
Need help guys.

Still having the same problem with my Mod. MJ1200 w/ 1.75" prop in 1.5" coupling.

Problem is that when I put pump in deeper water it rattles & stops working, but when i put near surface it works fine as it pulls air in.

I tried the mod on 2 different MJ 1200 bodies & get the same effect.

Anyone ever have this happen?

Kinda hard to tell you what I think the problem is without a photo of some sort.

 

[Timbo]

When the prop is pulling in air it takes less energy to drive the propeller. My guess is when you submerge it its drawing more energy then the pump can provide and stalling out. This kind of motor don't work that well if its stressed beyond its capabilities. This would be my conclusion.

My suggestion would be to try a smaller prop and see if that works.

 

[dhnguyen]

<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:

I had that happened to my mj400's once and a good cleaning and 15 minute bath in vinegar solved that.


D.

 

[jrcastro]

<a href=showthread.php?s=&postid=6802047#post6802047 target=_blank>Originally posted</a> by Timbo
When the prop is pulling in air it takes less energy to drive the propeller. My guess is when you submerge it its drawing more energy then the pump can provide and stalling out. This kind of motor don't work that well if its stressed beyond its capabilities. This would be my conclusion.

My suggestion would be to try a smaller prop and see if that works.

Thanks for the input, this sounds about right.
I will try with a smaller prop.

Whats weird is i tried the same 1.75" prop on a different housing same MJ motor & it worked fine. Only thing different was the placement of the prop. I placed it very close to the brace & had slots all the way near the brace.

I think i should leave a small allowance near the prop/brace area & not put any slots there.

 

[dhnguyen]

<a href=showthread.php?s=&postid=6802129#post6802129 target=_blank>Originally posted</a> by jrcastro
...
Whats weird is i tried the same 1.75" prop on a different housing same MJ motor & it worked fine. Only thing different was the placement of the prop. I placed it very close to the brace & had slots all the way near the brace.

I think i should leave a small allowance near the prop/brace area & not put any slots there.

That's your problem there I think. You have to have sufficient free room between the propeller and the cross brace especially if you have a stopper in there too.


I have ran the Dumas 1.75" propeller on a MJ900 without any issues even at deeper placement. Can't imagine the MJ1200 having an issue with not having enough juice to spin this prop at at deeper level.


D.

 

[jrcastro]

Thanks for the input D I think you are right.

Do you think the slots/holes have anything to do with it?
Maybe putting too much pressure against the prop when in deeper water. Therefore, making it rattle & stop.

The first one i created i had 6 slots & it worked perfect.
Second one i had 10 slots & it was almost to the brace end.

 

[dhnguyen]

No I don't think the extra slots would prevent the prop from spinning. It's more than likely that your propr is too close to the cross brace.

D.

 

[Jon770]

<a href=showthread.php?s=&postid=6802093#post6802093 target=_blank>Originally posted</a> by dhnguyen
I had that happened to my mj400's once and a good cleaning and 15 minute bath in vinegar solved that.


D.

What parts should I soak?

 

[dhnguyen]

The impeller

 

[Roland Jacques]

for what its worth i think the slots that are near the end cause more back pressure becace they want to change the direction of the flow. you my notice that slots near the end have water coming out of the housing not into the housing like it should be. thier is a point at which thier should be no slots. i think you should bearly see your porp though the last slot . but i could be wrong

 

[jrcastro]

Hey D.
Thanks for your help. I was able to make it work just buy pushing the prop back a lil as you instructed.

Which one do you think puts out more flow?
Your latest one (black) 1.5" Long

Or your first one (gray) 2.25" long

Do you think the length matters?


Thanks

 

[crypto]

i agree with "yourfishman", i think around the prop and further out you should not have the slots.

ideally you want smooth flow into the prop as well, on mine i decided to cut out the slots altoghether. i then put a large mesh screen around the housing.

 

[Jon770]

<a href=showthread.php?s=&postid=6810273#post6810273 target=_blank>Originally posted</a> by crypto
i agree with "yourfishman", i think around the prop and further out you should not have the slots.

ideally you want smooth flow into the prop as well, on mine i decided to cut out the slots altoghether. i then put a large mesh screen around the housing.

are you referring to my problem?

 

[shelburn61]

<a href=showthread.php?s=&postid=6809745#post6809745 target=_blank>Originally posted</a> by jrcastro

Your latest one (black) 1.5" Long

I just built one exactly like this. It's a 1.5 abs coupling right?
I can't get it to work for more than a few minutes without the propeller fouling.

My only tool is a dremel so maybe my cuts just aren't precise enough to keep things aligned, but I am wondering if there is something to the idea that enclosing the housing at the end would help stabilize the big 1.75 prop?

 

[dhnguyen]

<a href=showthread.php?s=&postid=6809745#post6809745 target=_blank>Originally posted</a> by jrcastro
...

Do you think the length matters?


Thanks

I noticed no difference in flow and that's why I opted to do it shorter.

D.

 

[shelburn61]

Anyone interested in cutting a housing for me? I can't do a decent job without the right tools. Please PM. I'll pay, of course.

 

[dhnguyen]

<a href=showthread.php?s=&postid=6810378#post6810378 target=_blank>Originally posted</a> by shelburn61
I just built one exactly like this. It's a 1.5 abs coupling right?
I can't get it to work for more than a few minutes without the propeller fouling.

My only tool is a dremel so maybe my cuts just aren't precise enough to keep things aligned, but I am wondering if there is something to the idea that enclosing the housing at the end would help stabilize the big 1.75 prop?

No actually that's a 1.5" PVC coupling not ABS. I just painted black with Krylon Fusion. What do you mean by propeller fouling?
Got any photos of yours?


D.