Dosing Pumps

[cyrilp]

Anybody using this kind of pumps?

Fluid Metering, Inc (http://www.fmipump.com/99pumpop.html)

[H20ENG]

Neat! Thats a new one to me, and I've seen tons of pumps.
Bet its an arm and 2 legs, though.
DIY???
Chris

[cyrilp]

Yes, they are pricey...
~$500 for OEM stepper motor driven unit

____
cyrilp

P.S. Will post some pictures of real pump later today

[Fredfish]

Hmmm...

Could make the shaft out of uhmw plastic. O-rings for a seal

I wonder how they couple the drive to the pump?

I wonder where you can get one of these surplus?

Anyone out there an engineer for abbot labs? :D :D

Fred.

[cyrilp]

Fredfish,

DIY seems absolutely impossible to me.
Precisely mated ceramic cylinder and piston will be a major problem. Surplus is the only option...

Anyway, here are some detailed pics:
http://www.smallreef.com/setup.html
____
cyrilp

[H20ENG]

I think it could be done with orings on a plastic shaft/ plunger.
How did you make an electronic bubble counter?

[Fredfish]

I agree H2OENG, but how the heck do you make the part on the drive mechanism with the ball in it that the rod from the pump shaft fits into?

I suppose it could be done, but not easily.

Cool pump though.

Fred.

[H20ENG]

Yeah, it'd be a little clunky without a nice machine shop, but could be done.
Looks like the angle of the pump head to the drive head is what adjusts volume (depth) of the stroke / cycle. Drill a hole into some UHMW tubing. Get a nylon ball to fit inside this hole. Drill the ball to thread a screw through to the pump plunger. Press fit some small washers over the ball into the hole to prevent the ball from coming out.
Are we on the right track here?

[Fredfish]

Are we on the right track here?

Yup.

From the pics, looks like the rod that fits into the ball is not threaded. It probably needs to move independantly from the ball.

Would a press fit washer stay in place on a piece of equipment that is continuously rotating? If the washers were also uhmw you could probably weld them in place.

I still can't quite visualize how the pump plunger mates into the drive shaft assembly. Why does the plunger not wobble off axis as the drive rotates? Hmmm... gonna need to set up a simple model to get a handle on this.

Fred.

[cyrilp]

Guys, please forget about diy...

Just shoot me an email if you want to play with this devices and I'll send you some (I bet you can't imagine how cheap they can be)

But keep in mind that you'll need a stepper motor driver to run it (I've got mine for $20 on eBay)

-----------------
And regarding "electronic bubble counter"....
That's a different story. Not finished yet - I'll post some update in a week.
But to start you can read this Omega's document (http://www.omega.com/toc_asp/frameset.html?book=Green&file=MASS_FLOW_REF)

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cyrilp

[Fredfish]

cyrilp

Don't have access to your email. I would love to play with one of these. You must have access to them surplus or something 'cause $500 is not cheap. :eek2:

email me so I can get back to you.

Fred.

[cyrilp]

Fredfish, YGPM

I've fixed my profile - e-mail accessible now

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cyrilp

[Scleractinian]

A couple of sellers on eBay have had these listed recently in quantity. They were cheap, but don't stepper motor drives need a proprietary control card? I looked at these as precision dosers, but decided to stick with my piston pump for continuous top off, my 4-channel peristaltic for phyto and C-Balance feed and a 1.4 gpm diaphragm pump operating on a 1% duty cycle for Nilsen reactor mixing and feed.


If I'm wrong about needing special control hardware, these stepper driven pumps become very interesting alternatives.


Rob

[SaltwaterSensei]

these pumps seem like alot of trouble to just dose some reef supplements. I made an easy doser out of an air pump and a 3 inch plastic tube.

Seems like something that one could acomlpish with alot less hassle.:) :hammer: :reading: :beachbum:

[Scleractinian]

I've used such a doser, and still occasionally use one for acclimation, etc. Try to dose a 2 part additive, pump viscous liquids or particulates (phyto), or push kalk from the basement to a tank in the living room with one though.

More complicated can mean easier, depending on what it is that you're trying to accomplish.

[SaltwaterSensei]

True. I guess, if the fluid you're trying to dose is really viscus then an air driven pump might be to inefficeint compared to that one or other ones more powerful. This pump however is indeed interesting and by looking at the little animation should work dispite the fluides viscosity.

[Fredfish]

Scleractinian

Can you post specs and make on that piston pump. I will be pumping phyto and am looking for a reliable, cost effective pump.

I suspect that the steppermotor on the FMI could be replaced with another type without too much difficulty.

Fred.

[Scleractinian]

I've never actually used the piston pump for phyto. I have used both a Buchler? 4-channel "polystaltic" peristaltic and a Cole Parmer Masterflex peristaltic to pump phyto and various food slurries.