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

[DonJasper]

What'll happen (without some sort of support for the front) is that the sides of a impellor rub against the sides of the hole in the housing. After awhile the plastic coating will rub away, and after a little while longer the magnet will get rubbed into a round pyramid shape. Then after awhile longer it won't spin around any more.

Anyone want a slightly damaged impellor? It's in mint condition. Only slight wear along the top of the magnet.

 

[want2reef]

I don't use anything to keep the prop from spinning backwards, no probs so far.

 

[GSerg2]

Mine starts the right direction the first time virtually every start.

 

[mmbuna]

Double propeller aseembly. Note the flexible airline tubing just slips onto the rigid tubing (section in red) and glued inplace with CA glue. The propellers are drilled out a bit so that the (1/8" OD?) rigid airline tubing will fit through.

dhnguyen (and all the others that gave this double-prop mod a go) what holds the two propellers together? In my first attempt at this, they keep falling apart (I am assuming since the outermost prop hits the stop and the innermost doesn't).
Glued them together with CrazyGlue and then used CrazyGlue again to glue the twin-prop assembly to the rigid tube. Still not good enough! Is the ThickCA Glue stronger/better for the type of plastic the props are made out of?

Is there a way we can bind them together mechanically (maybe a thin shaft that goes through both on the props, parallel to the carbon fiber axis?) AND glue them together?

 

[GSerg2]

I just used superglue to glue them together and to the shaft like you said. So far it works.

 

[dhnguyen]

mmbuna,


You got it all wrong

The propellers' holes have been drilled out a bit larger to fit/slip OVER the rigid tubing. If you do it right, you won't even need any glue at all to hold them in place.


D.

 

[GSerg2]

Whoops, I missed what you were trying to do. Of course D is correct. The props have to be drilled out to fit over the tubing. I still used a drop of glue to hold them in place but it may not be needed.

 

[Critter]

Same here... drilled out, little glue (which binds them in seconds so be quick) and couldn't move them now if I wanted to.. I would have to drill them out to reuse them.

<a href=showthread.php?s=&postid=6482833#post6482833 target=_blank>Originally posted</a> by GSerg2
Whoops, I missed what you were trying to do. Of course D is correct. The props have to be drilled out to fit over the tubing. I still used a drop of glue to hold them in place but it may not be needed.

 

[want2reef]

I drilled mine out too, and didn't use any glue.

 

[mmbuna]

D, I didn't make it clear in my post, but I did insert the rigid tubing INTO the propeller's base so that the rigid tube prodrudes maybe 1/4" past the props. Used crazyglue to hold props to one another AND prop assembly to the rigid tube.

You and want2reef mention that you didn't have to glue them. Was such a tight fit? Is friction only keeping them from slipping around the rigid tube?

Maybe my drilling skills need to improove!?

Anyway I will give it another shot with a smaller drill (maybe because I am using metric drills whilst the rigid tube is in inches and the fit is not 100% there!?)

 

[areze]

I actually had to take a dremel with a grinding wheel and "cone" the tip of the ridgid tubing to get it into the propellor, thats how tight the fit is.

you may have just thought that at that point it was too small and bored it out another notch.

 

[dhnguyen]

I found dark gray PVC pipes here

http://www.mcmaster.com

search for pipe > PVC Pipe > Dark Gray SCH 80

The ID and OD measurements of the 1 1/2" pipes are practically an exact fit for the MJ body.

Shape Pipe
Schedule 80
Pipe Type Unthreaded
Pipe Size 1-1/2"
Pipe to Pipe Connection Unthreaded (pipe)
Material PVC
Inside Diameter 1.476"
Outside Diameter 1.900"
Perforation Type Solid Pipe
Color Dark Gray
Specifications Met Not Rated

The MJ body measured at:
OD 1 15/16" which is about 1.9375"
ID 1 7/16" which is about 1.4375"


Just ordered some 5ft ones to try out. Will be here on Monday I'm told. I'll let you guys know how these work out.


D.

 

[kevin_mic]

Question for those who have made these. Just wondering who has bought the prop balancer kit, and those that have - did it make that much of a difference? (namely was their a lot less vibration/noise?)

 

[dhnguyen]

I haven't bought the prop balancer myself but it should help a lot with vibration and noise. At least one person who did this also claimed it so as well. Can't remember exactly who that did this though.

I used a ghetto prop balancer using the existing MJ rod placed on level raised platform. Then carefully see if I can balance the propeller so that both blades will balance out and neither is heavier than the other and just file off the prop blade a bit if one is heavier than the other. It is not exact as a prop balancer but close enough I think. One of these days soon I will have to break down and get a prop balancer though.


D.

 

[BCool]

With the 1.5" coupling can you use 2-1.75" props on a maxi jet 900 or do you need a stronger pump? For those of you who use 2-1.5" props on the 900 does it have power left to turn 2-1.75" props?

 

[dhnguyen]

I don't know really. Haven't tried a double 1.75" prop mod to say one way or another. You could volunteer yourself for this and let us know how you made out?

The MJ900 definitely has more than enough power to move one 1.75" prop so.... :hmm1:

D.

 

[BCool]

So, basically you think that it has good power with the dual 1.5 inch props. Thank you and I might end up being the volunteer, although I don't know if I want to break a maxi jet 900 to find out if it works.

 

[kevin_mic]

I thought I would make the observation that if you have a smaller tank (below 100 gallons) that 1.5" dual prop will put out as much flow as you can handle. Mine is a 75 gallon and my 1.5" prop easily takes care of one side of my tank.

 

[BCool]

I am doing a BB 30" cube. So what you are saying is that the 1.5" props on a 900 will be sufficient. I would appreciate your input.

 

[kevin_mic]

My maji-jet is a 1200 and with one 1.5" prop it spits out a TON of water. With your tank (30" cube -- 116 gallons) I think you could probably go either way and be ok. The 1.5" prop is the proven method so far but I guess it really depends on how much flow you want and how many maxi-jets your going to convert. All I was really trying to say is that if you have a smaller tank then the 1.5" prop works wonders and I doubt that their is any real need to go much bigger.