I got my hands on the MOAP (Mother Of All Pumps)

[UberBlue]

I just scored a Micropump series 101 centrifugal pump off Ebay

The housing and impeller are stainless steel 316. Everything else is PTFE (Teflon)



The cool thing about this bad boy is it uses a NEMA B23 motor mount. Those are pretty common so I should be able to pick up a DC brushless motor to compliment it. That of course means I can pick my flow rate and associated pump heat.

Another intersting thing about this pump is the impeller. It looks like it uses a hybrid closed impeller design. I'm speculating the white PTFE disk is hydraulicaly coupled to the face of the impeller at speed. That could explain the variences in the P/Q graph.

And the best part of all... It only cost me $50 brand spanking new. Still has the FME in the inlet/outlet.

[UberBlue]

Here's some more pics.

Hard to belive something that tiny can throw that kind of head.

[lolito_fr]

That looks real sweet.

quick+rough calc to get max head based on rotor diameter (d in m) and rpm:
hmax(m)=v^2/2.g
with v(m/s)=rpm.pi.d/60
g=9.8m/s^2

for 35mm dia rotor at 9000 rpm, we find hmax=13.9m
wow, don't you just love physics

[UberBlue]

Another advantage of a small diameter impeller is that less torque is required. Makes motor selection allot easier.

I'm damn excited. I had looked at these before but they are ~$300. Needless to say, I nearly soiled myself when I saw it with a "buy it now" button for $49.95.

Here's the motor I'm thinking about. I want to get it with a hall effect sensor so I can plug it into a fan header for RPM. Be a good way to correlate temp with motor RPM to find the sweet spot, and for software shut down should the pump ever die.

[lolito_fr]

Check the performance graphs, I'm not too sure about the continuous rated power output :shrug:

[UberBlue]

More than enough.

At 9K this pump only requires 13 in-oz. of torque. Looks like the B23-G-75 produces ~23 in-oz. @ 10K

The only concern I have is the current draw. 15.A @ 12 V = 186W. that's just a tad much for a rheostat. The B23-I-75 has the same specs but only draws 6.2 A, but probably at 3X the cost.

[lolito_fr]

ok, pay no heed, I'm just jealous, thats all!

seriously though, the pump pdf doesnt seem to mention torque requirements? I also need to convert oz-in into something meaningful (to me), like watts...

yeah, speed control will be a must. Look out for a PWM controller?

[UberBlue]

The PDF makes no mention of the torque requirements, but the motor it was attached to does.

To bad it's AC, brushed, and loud as hell. But I have plans for that controller. It's a variable AC controller. I'm wondering if I couldn't use it to control the AC voltage to a 12V dc power supply without blowing something up.

EDIT: GAH! Nevermind. It's a 90V DC variable power supply, but for the life of me I can't figure out why the motor is emblazened with 115V 60Hz AC.

[lolito_fr]

you scored the motor, pump _and_ controller for that price!? jeez.

On the downside, I would have thought pretty much any motor+pump running at 9krpm would be loud as hell. (with or without brushes)

[UberBlue]

99.9% of the motor noise was the commutation. Plus ozone smells funny.

At 9K RPM I don't think the noise is gonna be that bad considering the weight of the pump housing (~1 lb.). That should dampen down the high frequency impeller whine (go figure, 9KHZ or a harmonic of). That and mate it to a good quality, well balanced, sealed, and heavy motor I should be set.

[Butcher]

In theory it would be no noisier than a HDD and they're pretty quiet.

[lolito_fr]

Butcher, is your harddrive motor rated for 160W shaft power

[Butcher]

Seems unlikely, more like 6W.