Pump for nano. AKA Low profile magnet driven external pump.

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Nov 18, 2006
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Seattle/Sammamish, WA
So my K-nano isnt cutting it. And in addition to being too big, I cant control it. So... I built a powerhead myself.

Dry Side
DSCN1680.jpg


Wetside
DSCN1678.jpg


Underside of Wetside
DSCN1679.jpg


Dryside + Wetside with a 1/4" acrylic inbetween
DSCN1677.jpg


Controller
DSCN1681.jpg


HD Video will come tomorrow as well as the finished touches.
 
lol, yeah it is. I was actually making the cover for the wet side -.- I was drilling a small piece of pvc. I didnt have it clamped down and the drill took it and ripped 1/4 of my thumb nail up. Still hurts like sh*t and I didnt use that cover... FML.

I'm going to redo the cover so that its a 3/4" long piece of PVC, just long enough to cover the prop and drill holes along it to give it water to push. If that isnt enough.... then.. I'll make a mesh cover out of window screen or something like that.

So when I tested this thing, the flow diameter was HUGE. it was at least 3x the size of the prop, which is 1.2" I cant wait to try this under a larger amount of water and compare the flow to that of the k-nano.

Unfortunately, this pump is only for nanos. The operation on the dry side is virtually silent. Unlike most large/fast brushed/brushless motors. And because it is silent, it draws little power so less torque but high rpm, which essentially makes this motor possible for this application. If the rpm was low and the torque was low, it would be nearly impossible to start it.
 
Ouch!

That pump looks so sweet though. Have you seen parts to make a bigger one? I could use another "Vortech" on my bigger tank.

How much did it cost to make your pump?
 
Well, heres a price rundown:

Motor: 5$
Controller: 5$
Prop: 3.99$
Magnets: 5.25$
Misc Hardware: 5$

I had glue/epoxy/pvc, but if you didn't: 8$

Total price for me: ~25$
I did drop one prop in the toilet... and it snapped into many pieces... yesterday was not a good day. +3.99$

Well the wetside can be used with a stronger motor, just a magnet number increase would solve that side. Now for the dryside, the motor I chose was a COMPLETELY silent one. But say if you wanted to push closer to 1000-2000gph, the motor would be (1) more expensive, around 20$ and (2) MUCH louder. Unless it was a quality motor, or one that you wound yourself, which is cheaper. It can easily be done with a mediocre fast motor that spins upwards of 3000rpm with good torque, but it would definitely be as loud, if not louder than your skimmer..

pics to come, I just fabricated the cover for the wetside, its currently drying and afterwards, I need to spray paint it.

Video by tonight.
 
Thanks Rob,

When I get around to it, I'll try to design a large version of this pump for all you.... big tanked folk.. hahaha :p

dimensions of the wetside: 1.75"x1.75"x1.25" (Footprint x Height)
dimensions of the dryside: 2" diameter circle x 1.25" tall
 
Awesome. I've considered doing this myself. I'd love to see some more detailed build instructions
 
Thanks man.
Now that I've actually tested this pump, I can say that its probably pushing close to 180gph, but I really have no way to measure this... (does someone know how?)

The motor I was using was running at a stock (air resistance) of 2500rpm and .17A This gave me ~180gph. (the motor does not run at 2500rpm under water, theres magnet resistance and water resistance)

Theres another motor, it runs at 8000rpm and 1.5A. This is the motor I would use if I wanted to make a bigger pump. Although this motor is ~25$
 
Haha, true.

I think I just found my next motor. I'll be using the same wet side. Just modding the dryside with a new motor..... hopefully the magnets are enough especially since rpm will be ramped way up...
 
The new motor I got today was closer to 10,000rpm and 1A but it still didnt have enough torque. Does anyone have any ideas as to which brushless motors are very quiet but still quite powerful? needs to be at least ~1500rpm
 
So after thinking about a more powerful DIY exterior motor driven magnetic pump, I have come to the conclusion that it's just not in my best interest to search for one. I have discovered that the mj1200 runs at 1800rpm (under load) and with the prop mod, it moves 1500gph. So that is a goal for someone to shoot for when picking a motor. 1500rpm under load, and it varies what it is without load. (depends on the torque) and I havent looked into how much torque it takes to move water or how the torque varies with prop angles and etc. etc.

What I did do was finalize my nano sized DIY exterior motor driven magnetic pump so that it could be run in my 8g sps tank. Which might I add, is 100% sps now :)

Final Thoughts:
I did locate the vortech mp pump patent: HereAnd they said that the wetside and dryside were held together by the drive magnets and none other using magnets of a perferd 5 pounds. I, on the other hand, couldnt use 5 pound magnets because My motor was of too low torque. I used closer to 1.2 pound magnets, which was not enough to hold the 2 pieces together. So I added a third magnet just above the dryside housing and I encased a magnet in epoxy and just put it in the tank to hold the dryside on the other side. You will see a random black dot in the pictures, thats the wetside holding magnet and also a buldge on the housing of the dryside and thats the dryside holding magnet.

Final Pictures:
Wetside top down
DIYvortech3.jpg

Wetside under:
DIYvortech1.jpg

Side by Side:
DIYvortech2.jpg

Side by Side top down:
DIYvortech4.jpg


So With the rebuild of the wetside underside, I have decreased the friction which made the pump spin faster and push more water. As a rough guestimate comparing mainly to my k-nano, it pushes ~220gph with a flow diameter of 5"

The wetside is 1.25" in diameter, and 1.25" in height.

I'll post a video of it operating in my cube sometime tomorrow. This is WAY more quiet than a vortech. Some do say that a vortech is very quiet, but I have my skimmer off during the day, so there is zero sound (I have 2 80mm pc fans but those are only 15 db) Its a little louder than a k-nano when its submerged and you're listening from out of the water.

I dont know if I should post a tutorial or not. Although alot of the parts I used and the techniques I used in my nano build could be used for a larger sized pump in the future if someone wanted to do it. Give me some feedback on this please.
 

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