Now I'm working on the rest of the housing.

oh that's nice, I like that:drool:

Hope this turns out well.

And if low pressure is an issue you can always run a bunch of these in parellel :).

parallel is for more flow volume, series is for higher pressure.

What about using a motor from a hard drive??? Preferably from a 7200 RPM drive. I would assume a HD motor would have a lot more power (torque - whatever) than a fan motor.

Hell...it even has the disks for the impeller ;)

Nico!, how does it work?, the epox will go all around the outside of the wooden mold?...

It's amazing stuff all right, I never knew it could be used like you've shown us, opened up a whole new area...

I'd like to see your 'swirl' baseplate machined as well...

Kudos...

PS, I've just noticed the channel widens out towards the exitpoint, good thinking!, wonder if it'll work?...

... and it's perfectly balanced

I've thought that; I have an old hard drive dismantled from where I take out the magnet of the head assembly. Unfortunately the motor electronics are located on the drive pcb, and it only spins for 5 seconds without the head. :(

nevermind, that was a work in progress pic, it lacks the outer shape.

I'm using slow curing epoxi, the one used for fibers impregnation for reinforced plastics. It's a lot more fluid than adhessive tipe, allows a good work time, it's absolutely waterproof, and I buy it by the Kg. :D

For the mold I'm using soft cardboard, painted with errr unmoldant? "desmoldante" in spanish.

You could use an old cd-rom motor. I know some RC guys who use those...

Seems like an interesting project. If it works we'll all have a new toy to get :p

Is that cardboard you've used to mold the impellor housing?, looks like wood strips!...

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I'd imagine HD & CD motors would be too wimpy, try the windscreen wiper motor of a car nico, they're 12V and you'd have some serious head!...

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Thinking about it, it HAS to be a fan motor, the magnets have to be outside the sealed coils, with motors the coils are usualy on the shaft that spins. Anything that uses brushes or a simular principal would be useless...

'Normal' motors are back to front/topsy~turvy if you know what I mean :shrug: ...

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These would make excellent pumps for NB & GPU only loops, coupled with a micro~radiator...

As I remember it, CD and HD motors are steppers, but the power rating would still be fairly weak. It should be more powerful than a fan motor though.

Get a bigger fan. You can probably find surplus 120mm+ fans with very high powered motors if you look hard enough. I know I've seen PDFs for 20w DC fans before.

True, but they're "low-torque" motors. Pressing it in water will cause it to run much slower, and with less force/torque.

The stepper is starting to look good to me, but would require a controller. It could be tweaked for maximum rpm/torque...

Well, this one is commonly called "Wood cardboard" :p It's 1mm thick but very soft to cut. I used a continuous strip with several half depht cuts to curve it.

I've seen 2 amps 12v 120mm fans, but are expensive to buy new to tear it apart, not very cost effective.:shrug:

Maybe it's possible to buy the brushless DC motor alone...

Hmm...

i got one of those (170mm) its a BEAST! 300cfm

i might rip it apart if this works good enough, only paid $15CAD :cool:

the project is very interesting considering the material of choise,

Pass or fail, I think it has broaden the insites of some of the DIYers as to the mediums we can use.

Now what I would like to see, is a HOW TO article writen up on just how you made the parts. From start to finish, to get an idea as to what other uses it may have (Jet knozzels comes to mind) and how hard or easy it is to work with.


PLEASE.... I asked nicley

Thanks, you flatter me :)

I don’t consider myself an expert in plastics; just have some DIY experience that can be helpful for the novice. Unfortunately can’t make a step by step guide as I don’t have many pictures of the process. Now I have the pump almost done but my brother is using the digicam for some days so there’s no pics to show. :(

The most commonly available resin for diy work is polyester, it’s very cheap and hard, but brittle. It requires precise dosification of components at hard to measure 50/1 relationships. That’s why I prefer epoxy, It’s more expensive but easier to mix, and very tough. It’s clear and can be polished for a crystal finish but you need to be very careful at mixing, as it likes to trap tiny bubbles. Ideally you should put the fresh mix in a vacuum chamber to extract all bubbles, but that’s not common equipment for DIYers. Another thing important with epoxy is curing; it could take weeks to reach at ambient temps the hardness you get with some hours of heat. In summer just can be left under the sun (if your sun is good enough :p ), or leave it close to a hot lamp.

Hope this helps, feel free to ask anything you want.

Ok, so can you just place the piece in the oven at say, 200 degrees? (F)? or is that too hot? To cure it, i mean.

That little fan does in my honest opinion will not have enough tourque to give you more than a mear trickle.

I have made alot of rc boats and i am very familiar with the dynamics of water. The overall drag surface of a pump impellar is extremely large and requires alot of torque something that little motor will not give. This is just my two cents, and in this case i would love to be proven wrong, as I like how the structure of the pump is coming along.

He stated before that it is a test, and the real pump will be made by the "largest fan he can find".

Interesting enough, i have an old blow drier electrical motor wich is rated for 12v->24v . It has a substancial amout of torq. I'm not really interested in making a 12v pump but it is a good place to look for more "powerful" dc engines.

A temp controlled oven is ideal, just don't use the same you use for food cause everything will taste like plastic... :p I don't know the exact temp, just know it by touch. Is something that you can grab without burning, but not hold very much. sorry, no more precise data. :D With more heat it hardens faster, but it becomes yellowish.

About motors, the key factor is "brushless", to be able to seal it completely. Common DC motors will require a seal in the rotating shaft that is going to fail over time.

You know what are great dc motors? 5 Volt Drill Motors. They are rated at 5 volts but they run just fine at 12. The torque is truly amazing compared to the power consumption. They are also very small and easy to work with. One problem, when run at 12 volts and at alot of strain they make a considerable amount of heat. Also at 5 volts they work pretty good too.

Here is a nice place that has a lot of motors and fans (one fan reaches 12000, yes twelve thousand, RPM.) I was thinking of buying a high quality mirror from there to use for lapping.

Here's the the dc motors i had laying around:(big pictures)

http://clientes.netvisao.pt/carlo001/dc1.jpg

http://clientes.netvisao.pt/carlo001/dc2.jpg

Both are fast motors, with a good amount of torq.

Think how a FAN motor is constructed, it has the copperwire coils in the centre(easy to resin coat/seal) and the magnet on the outside, it's the outside that spins.

With a 'normal' motor the coils are on the outside of the shaft/magnets that spin, usualy in a curcular steel tube/case. It might be possible to encase the lot then lathe the outside and drill the centre, but then there's the bearings as well!, also the shaft is usualy ferrous metal... It's impossible if Nico says so, I recon he's carefuly considered it already :( ...

Needs to be a FAN motor people :shrug: ...

Does it HAVE to be DC though Nico?. I trust your resin as much as I trust Eheims :dome: ...

It's DC for plug and play convenience, forget about relays. :cool:

Terramex, it seems that if you turn on that motor, some spiders are going to loose their home. :D

I've made some tests, and the water drag is incredible. Just realized that was a mistake when I said that the bare hub makes 9700 rpm underwater. The motor with the base disk makes about 10500 rpm on air, and between 2200 and 3000 in water, depending on the amount of air bubbles inside the hub. :eek:

Just discovered that a small amout of air, between the coils and the magnet, improves performance a lot. Those are two concentric cylindrical surfaces very close together, and the viscosity of water between them makes a big drag.

And gekkos.
 

Probably :D. It does move alot of air, but also makes a considerable amout of noise. Anyway, i was thinking and it's a good assumption to say it wouldnt work underwater. Coating it and maintaining the rotor in working order would probably take too much time and effort ...

PS : full assembley, i found the rest later.

First performance numbers!
 

The pump, with just a 40 mm disc as the impeller, can move some water!

I tested it with 50 cm of 1/2" hose, moves 170 L/H at 0 head, and have the incredible max head of 20 cm! :p

Well, I'm happy this is starting to work, and remember that this is just a base line; Still need to make the impeller. I'm amazed that just a single disk can do something. :)

Find yourself on old cordless drill and take the motor. Those motors are designed for torque. Work excellent for water tasks.

Re: First performance numbers!
 

so are you going to make an impeller, or use multiple disks ala tesla?

and we want pics! (congrats on getting it working to some degree!)

Re: First performance numbers!
 

That's actually pretty impressive! I didn't think it could even get to that! Congratulations, and keep up the good work!